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Wu Q, Ye F, Gu Q, Shao F, Long X, Zhan Z, Zhang J, He J, Zhang Y, Xiao Q. A customised down-sampling machine learning approach for sepsis prediction. Int J Med Inform 2024; 184:105365. [PMID: 38350181 DOI: 10.1016/j.ijmedinf.2024.105365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 12/17/2023] [Accepted: 01/29/2024] [Indexed: 02/15/2024]
Abstract
OBJECTIVE Sepsis is a life-threatening condition in the ICU and requires treatment in time. Despite the accuracy of existing sepsis prediction models, insufficient focus on reducing alarms could worsen alarm fatigue and desensitisation in ICUs, potentially compromising patient safety. In this retrospective study, we aim to develop an accurate, robust, and readily deployable method in ICUs, only based on the vital signs and laboratory tests. METHODS Our method consists of a customised down-sampling process and a specific dynamic sliding window and XGBoost to offer sepsis prediction. The down-sampling process was applied to the retrospective data for training the XGBoost model. During the testing stage, the dynamic sliding window and the trained XGBoost were used to predict sepsis on the retrospective datasets, PhysioNet and FHC. RESULTS With the filtered data from PhysioNet, our method achieved 80.74% accuracy (77.90% sensitivity and 84.42% specificity) and 83.95% (84.82% sensitivity and 82.00% specificity) on the test set of PhysioNet-A and PhysioNet-B, respectively. The AUC score was 0.89 for both datasets. On the FHC dataset, our method achieved 92.38% accuracy (88.37% sensitivity and 95.16% specificity) and 0.98 AUC score on the test set of FHC. CONCLUSION Our results indicate that the down-sampling process and the dynamic sliding window with XGBoost brought robust and accurate performance to give sepsis prediction under various hospital settings. The localisation and robustness of our method can assist in sepsis diagnosis in different ICU settings.
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Affiliation(s)
- Qinhao Wu
- Apriko Research, Eindhoven, the Netherlands; Department of Mathematics and Computer Science, Eindhoven University of Technology, De Zaale, Eindhoven, 5612 AZ, Noord Brabant, the Netherlands
| | - Fei Ye
- Apriko Research, Eindhoven, the Netherlands
| | - Qianqian Gu
- Digital, Data and Informatics, Natural History Museum, London, SW7 5BD, United Kingdom
| | - Feng Shao
- Apriko Research, Eindhoven, the Netherlands
| | - Xi Long
- Department of Electrical Engineering, Eindhoven University of Technology, De Zaale, Eindhoven, 5612 AZ, Noord Brabant, the Netherlands
| | - Zhuozhao Zhan
- Department of Mathematics and Computer Science, Eindhoven University of Technology, De Zaale, Eindhoven, 5612 AZ, Noord Brabant, the Netherlands
| | - Junjie Zhang
- E.N.T. Department, the First Hospital of Changsha, University of South China, Changsha, 410005, China
| | - Jun He
- Department of Critical Care Medicine, the First Hospital of Changsha, University of South China, Changsha, 410005, China
| | - Yangzhou Zhang
- Department of Critical Care Medicine, Xiangya Hospital, Central South University, Changsha, Changsha, 410008, China.
| | - Quan Xiao
- E.N.T. Department, the First Hospital of Changsha, University of South China, Changsha, 410005, China.
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van den Heuvel ER, Almalik O, Zhan Z. Simulation models for aggregated data meta-analysis: Evaluation of pooling effect sizes and publication biases. Stat Methods Med Res 2024; 33:359-375. [PMID: 38460950 DOI: 10.1177/09622802231206474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2024]
Abstract
Simulation studies are commonly used to evaluate the performance of newly developed meta-analysis methods. For methodology that is developed for an aggregated data meta-analysis, researchers often resort to simulation of the aggregated data directly, instead of simulating individual participant data from which the aggregated data would be calculated in reality. Clearly, distributional characteristics of the aggregated data statistics may be derived from distributional assumptions of the underlying individual data, but they are often not made explicit in publications. This article provides the distribution of the aggregated data statistics that were derived from a heteroscedastic mixed effects model for continuous individual data and a procedure for directly simulating the aggregated data statistics. We also compare our simulation approach with other simulation approaches used in literature. We describe their theoretical differences and conduct a simulation study for three meta-analysis methods: DerSimonian and Laird method for pooling aggregated study effect sizes and the Trim & Fill and precision-effect test and precision-effect estimate with standard errors method for adjustment of publication bias. We demonstrate that the choice of simulation model for aggregated data may have an impact on (the conclusions of) the performance of the meta-analysis method. We recommend the use of multiple aggregated data simulation models to investigate the sensitivity in the performance of the meta-analysis method. Additionally, we recommend that researchers try to make the individual participant data model explicit and derive from this model the distributional consequences of the aggregated statistics to help select appropriate aggregated data simulation models.
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Affiliation(s)
- Edwin R van den Heuvel
- Department of Mathematics and Computer Science, Eindhoven University of Technology, Eindhoven, the Netherlands
- Department of Preventive Medicine and Epidemiology, School of Medicine, Boston University, Boston, USA
| | - Osama Almalik
- Department of Mathematics and Computer Science, Eindhoven University of Technology, Eindhoven, the Netherlands
| | - Zhuozhao Zhan
- Department of Mathematics and Computer Science, Eindhoven University of Technology, Eindhoven, the Netherlands
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Lorente Flores CM, Zhan Z, Scholten AWJ, Hutten GJ, Vervoorn M, Niemarkt HJ. The Effects of a New Wireless Non-Adhesive Cardiorespiratory Monitoring Device on the Skin Conditions of Preterm Infants. Sensors (Basel) 2024; 24:1258. [PMID: 38400415 PMCID: PMC10892062 DOI: 10.3390/s24041258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 02/08/2024] [Accepted: 02/14/2024] [Indexed: 02/25/2024]
Abstract
AIM The aim of our study was to investigate skin conditions when wearing and removing a novel wireless non-adhesive cardiorespiratory monitoring device for neonates (Bambi-Belt) compared to standard adhesive electrodes. STUDY DESIGN This was a prospective study including preterm neonates requiring cardiorespiratory monitoring. Besides standard electrodes, the infants wore a Bambi Belt for 10 consecutive days. Their skin conditions were assessed using Trans Epidermal Water Loss (TEWL) and the Neonatal Skin Condition Score (NSCS) after daily belt and standard electrode removal. The ∆TEWL was calculated as the difference between the TEWL at the device's location (Bambi-Belt/standard electrode) and the adjacent control skin location, with a higher ∆TEWL indicating skin damage. RESULTS A total of 15 infants (gestational age (GA): 24.1-35.6 wk) were analyzed. The ΔTEWL significantly increased directly after electrode removal (10.95 ± 9.98 g/m2/h) compared to belt removal (5.18 ± 6.71 g/m2/h; F: 8.73, p = 0.004) and after the washout period (3.72 ± 5.46 g/m2/h vs. 1.86 ± 3.35 g/m2/h; F: 2.84, p = 0.09), although the latter did not reach statistical significance. The TEWL was not influenced by prolonged belt wearing. No significant differences in the NSCS score were found between the belt and electrode (OR: 0.69, 95% CI [0.17, 2.88], p = 0.6). CONCLUSION A new wireless non-adhesive device for neonatal cardiorespiratory monitoring was well tolerated in preterm infants and may be less damaging during prolonged wearing.
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Affiliation(s)
- Carmen M. Lorente Flores
- Máxima Medical Center, Department of Neonatology, De Run 4600, 5504 DB Veldhoven, The Netherlands; (C.M.L.F.); (M.V.)
| | - Zhuozhao Zhan
- Department of Mathematics and Computer Science, Eindhoven University of Technology, Groene Loper 3, 5612 AE Eindhoven, The Netherlands;
| | - Anouk W. J. Scholten
- Department of Neonatology, UMC location University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands (G.J.H.)
- Amsterdam Reproduction & Development Research Institute, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
| | - Gerard J. Hutten
- Department of Neonatology, UMC location University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands (G.J.H.)
- Amsterdam Reproduction & Development Research Institute, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
| | - Marieke Vervoorn
- Máxima Medical Center, Department of Neonatology, De Run 4600, 5504 DB Veldhoven, The Netherlands; (C.M.L.F.); (M.V.)
| | - Hendrik J. Niemarkt
- Máxima Medical Center, Department of Neonatology, De Run 4600, 5504 DB Veldhoven, The Netherlands; (C.M.L.F.); (M.V.)
- Department of Electrical Engineering, Eindhoven University of Technology, Groene Loper 3, 5612 AE Eindhoven, The Netherlands
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Huang Z, Tu X, Yu T, Zhan Z, Lin Q, Huang X. Peritumoural MRI radiomics signature of brain metastases can predict epidermal growth factor receptor mutation status in lung adenocarcinoma. Clin Radiol 2024; 79:e305-e316. [PMID: 38000953 DOI: 10.1016/j.crad.2023.10.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 10/05/2023] [Accepted: 10/18/2023] [Indexed: 11/26/2023]
Abstract
AIM To investigate whether magnetic resonance imaging (MRI) radiomics features of brain metastases (BMs) can predict epidermal growth factor receptor (EGFR) mutation status in lung adenocarcinoma. MATERIALS AND METHODS Between June 2014 and December 2022, 58 histopathologically confirmed lung adenocarcinoma patients (27 with EGFR wild-type, 31 with EGFR mutation) who underwent gadobenate dimeglumine-enhanced brain MRI were recruited retrospectively. A total of 123 metastatic brain lesions were allocated randomly into the training cohort (n=86) and test cohort (n=37) at a ratio of 7:3. Radiomics models based on multi-sequence MRI images in different regions such as volume of interest (VOI)enhancing tumour, VOIwholetumour, VOIperitumour 1mm, VOIperitumour 3mm, and VOIperitumour 5mm were built. The optimal radiomics model was integrated into the clinical or radiological indicators to construct a fusion model through multivariable logistic regression analysis. RESULTS The optimal radiomics model based on the VOIperitumour 1mm, a combination of nine features selected from the fluid-attenuated inversion recovery (FLAIR) sequence, yielded areas under the curves (AUCs) of >0.75 in the training and test cohorts. The prediction of the fusion model with integration of clinical factors (age) and radiomics score (the optimal radiomics model) was not better than that of the optimal radiomics model alone in the test cohort (AUC: 0.808 and 0.785, respectively, p=0.525). CONCLUSION The FLAIR radiomics model based on VOIperitumour 1mm as an effective biomarker helps predict EGFR mutation status in lung adenocarcinoma patients with BMs and then assists clinicians in selecting optimal treatment strategies.
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Affiliation(s)
- Z Huang
- Department of Radiology, Longyan First Affiliated Hospital of Fujian Medical University, No. 105 North 91 Road, Xinluo District, Fujian, 364000, China.
| | - X Tu
- Department of Orthopedics, Longyan First Affiliated Hospital of Fujian Medical University, No. 105 North 91 Road, Xinluo District, Fujian, 364000, China
| | - T Yu
- Department of Radiology, Longyan First Affiliated Hospital of Fujian Medical University, No. 105 North 91 Road, Xinluo District, Fujian, 364000, China
| | - Z Zhan
- Department of Radiology, Longyan First Affiliated Hospital of Fujian Medical University, No. 105 North 91 Road, Xinluo District, Fujian, 364000, China
| | - Q Lin
- Department of Radiology, Longyan First Affiliated Hospital of Fujian Medical University, No. 105 North 91 Road, Xinluo District, Fujian, 364000, China
| | - X Huang
- Department of Radiology, Longyan First Affiliated Hospital of Fujian Medical University, No. 105 North 91 Road, Xinluo District, Fujian, 364000, China
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van den Berge BA, Omar FMA, Werker PMN, Zhan Z, van den Heuvel ER, Broekstra DC. Treatment durability of limited fasciectomy vs. percutaneous needle fasciotomy for Dupuytren's disease. Plast Reconstr Surg 2024:00006534-990000000-02239. [PMID: 38289897 DOI: 10.1097/prs.0000000000011322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
BACKGROUND Patients with Dupuytren's disease (DD) are mostly surgically treated by percutaneous needle fasciotomy (PNF) or limited fasciectomy (LF), but data on time intervals to retreatment is lacking. We aimed to estimate the risk of retreatment within certain time periods after treatment with PNF and LF. METHODS We used data of participants of a cohort study on the course of DD who were treated only with PNF or LF. Our primary outcome measure was time to retreatment of DD. We included sex, age at first treatment and having a first degree relative with DD as confounders in our analysis. We applied a bivariate gamma frailty model to estimate the risk of retreatment within 1,3,5, 10 and 20 years after treatment with PNF and LF. RESULTS The time to retreatment was significantly shorter after treatment with PNF than after LF (Wald test 7.56, p<0.001). The estimated 10-year risk of retreatment for men who underwent their first treatment at a younger age and with a first degree relative with DD was 97% after PNF and 32% after LF. The estimated 10-year risk for women who underwent their first treatment at an older age without a first degree relative with DD was 20% after PNF and 6% after LF. CONCLUSIONS Our results show that the patients treated with PNF have a higher risk of retreatment. The results of this study could contribute to individualized information on the treatment durability in the future, which would improve patient counseling about the expected retreatment needs.
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Affiliation(s)
- Bente A van den Berge
- University of Groningen, University Medical Center Groningen, Department of Plastic Surgery, Groningen, the Netherlands
| | - Fatuma M A Omar
- Eindhoven University of Technology, Department of Mathematics and Computer Science, Eindhoven, the Netherlands
| | - Paul M N Werker
- University of Groningen, University Medical Center Groningen, Department of Plastic Surgery, Groningen, the Netherlands
| | - Zhuozhao Zhan
- Eindhoven University of Technology, Department of Mathematics and Computer Science, Eindhoven, the Netherlands
| | - Edwin R van den Heuvel
- Eindhoven University of Technology, Department of Mathematics and Computer Science, Eindhoven, the Netherlands
| | - Dieuwke C Broekstra
- University of Groningen, University Medical Center Groningen, Department of Plastic Surgery, Groningen, the Netherlands
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Scholten AWJ, Zhan Z, Niemarkt HJ, Vervoorn M, van Leuteren RW, de Jongh FH, van Kaam AH, Heuvel ERVD, Hutten GJ. Cardiorespiratory monitoring with a wireless and nonadhesive belt measuring diaphragm activity in preterm and term infants: A multicenter non-inferiority study. Pediatr Pulmonol 2023; 58:3574-3581. [PMID: 37795597 DOI: 10.1002/ppul.26695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 08/18/2023] [Accepted: 09/05/2023] [Indexed: 10/06/2023]
Abstract
INTRODUCTION We determined if the heart rate (HR) monitoring performance of a wireless and nonadhesive belt is non-inferior compared to standard electrocardiography (ECG). Secondary objective was to explore the belt's respiratory rate (RR) monitoring performance compared to chest impedance (CI). METHOD In this multicenter non-inferiority trial, preterm and term infants were simultaneously monitored with the belt and conventional ECG/CI for 24 h. HR monitoring performance was estimated with the HR difference and ability to detect cardiac events compared to the ECG, and the incidence of HR-data loss per second. These estimations were statistically compared to prespecified margins to confirm equivalence/non-inferiority. Exploratory RR analyses estimated the RR trend difference and ability to detect apnea/tachypnea compared to CI, and the incidence of RR-data loss per second. RESULTS Thirty-nine infants were included. HR monitoring with the belt was non-inferior to the ECG with a mean HR difference of 0.03 beats per minute (bpm) (standard error [SE] = 0.02) (95% limits of agreement [LoA]: [-5 to 5] bpm) (p < 0.001). Second, sensitivity and positive predictive value (PPV) for cardiac event detection were 94.0% (SE = 0.5%) and 92.6% (SE = 0.6%), respectively (p ≤ 0.001). Third, the incidence of HR-data loss was 2.1% (SE = 0.4%) per second (p < 0.05). The exploratory analyses of RR showed moderate trend agreement with a mean RR-difference of 3.7 breaths/min (SE = 0.8) (LoA: [-12 to 19] breaths/min), but low sensitivities and PPV's for apnea/tachypnea detection. The incidence of RR-data loss was 2.2% (SE = 0.4%) per second. CONCLUSION The nonadhesive, wireless belt showed non-inferior HR monitoring and a moderate agreement in RR trend compared to ECG/CI. Future research on apnea/tachypnea detection is required.
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Affiliation(s)
- Anouk W J Scholten
- Department of Neonatology, Emma Children's Hospital, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Amsterdam Reproduction & Development Research Institute, Amsterdam, The Netherlands
| | - Zhuozhao Zhan
- Department of Mathemaatics and Computer Science, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Hendrik J Niemarkt
- Department of Neonatology, Màxima Medical Center, Veldhoven, The Netherlands
| | - Marieke Vervoorn
- Department of Neonatology, Màxima Medical Center, Veldhoven, The Netherlands
| | - Ruud W van Leuteren
- Department of Neonatology, Emma Children's Hospital, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Amsterdam Reproduction & Development Research Institute, Amsterdam, The Netherlands
| | - Frans H de Jongh
- Department of Neonatology, Emma Children's Hospital, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Faculty of Science and Technology, University of Twente, Enschede, The Netherlands
| | - Anton H van Kaam
- Department of Neonatology, Emma Children's Hospital, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Amsterdam Reproduction & Development Research Institute, Amsterdam, The Netherlands
| | - Edwin R van den Heuvel
- Department of Mathemaatics and Computer Science, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Gerard J Hutten
- Department of Neonatology, Emma Children's Hospital, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Amsterdam Reproduction & Development Research Institute, Amsterdam, The Netherlands
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van den Broek JM, Heydari S, Zhan Z, van 't Veer M, Sammali F, Overeem S, van den Heuvel ER, Dekker LR. Can body position be arrhythmogenic? Sleep Med 2023; 105:21-24. [PMID: 36940516 DOI: 10.1016/j.sleep.2023.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 02/19/2023] [Accepted: 03/04/2023] [Indexed: 03/12/2023]
Abstract
INTRODUCTION Palpitations occurring in specific body positions are often reported by patients, but the effect of body position on arrhythmia has received little research attention. We hypothesize that resting body position can exert pro-arrhythmogenic effects in various ways. For example, lateral body position is known to increase change atrial and pulmonary vein dimensions. METHODS This observational study capitalizes on overnight polysomnography (PSG) recordings from a tertiary sleep clinic. PSGs were retrieved based on any mention of cardiac arrhythmia in the clinical report, irrespective of primary sleep diagnosis or (cardiac) comorbidities. Every instance of atrial ectopy was annotated and subgroups with a homogenous rate of atrial ectopy were created based on the Dunn index. A generalized linear mixed-effects model using age, sex, gender, sleep stage and body position was used to analyse the total amount of atrial ectopy in each combination of sleep stage and body position. Backward elimination was then performed to select the best subset of variables for the model. Presence of a respiratory event was then added to the model for the subgroup with a high atrial ectopy rate. RESULTS PSGs of 22 patients (14% female, mean age 61y) were clustered and analysed. Body position, sleep stage, age or sex did not have a significant effect on atrial ectopy in the subgroup with a low rate of atrial ectopy (N = 18). However, body position did significantly affect the rate of atrial ectopy in the subgroup with a high rate of atrial ectopy (N = 4; 18%). Respiratory events significantly altered the atrial ectopy rate in only three body positions across two patients. DISCUSSION In each individual with a high rate of atrial ectopy, the rate of atrial ectopy was significantly higher in either left or right decubital or supine position. Increase in atrial wall stretch in lateral decubital position and obstructive respiratory events in positional sleep apnea are two possible pathophysiological mechanisms, while avoidance of a body position due to symptomatic atrial ectopy in that position is an important limitation. CONCLUSION In a selected cohort of patients with a high rate of atrial ectopy during overnight polysomnography, the occurrence of atrial ectopy is related to resting body position.
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Affiliation(s)
- Jlpm Maarten van den Broek
- Department of Cardiology, Catharina Hospital, Eindhoven, the Netherlands; Department of Electrical Engineering, Eindhoven University of Technology, the Netherlands.
| | - Samaneh Heydari
- Department of Mathmatics, Eindhoven University of Technology, the Netherlands.
| | - Zhuozhao Zhan
- Department of Mathmatics, Eindhoven University of Technology, the Netherlands.
| | - Marcel van 't Veer
- Department of Cardiology, Catharina Hospital, Eindhoven, the Netherlands.
| | - Federica Sammali
- Department of Electrical Engineering, Eindhoven University of Technology, the Netherlands.
| | - Sebastiaan Overeem
- Kempenhaeghe Centre for Sleep Medicine, Heeze, the Netherlands; Department of Electrical Engineering, Eindhoven University of Technology, the Netherlands.
| | | | - Lukas R Dekker
- Department of Cardiology, Catharina Hospital, Eindhoven, the Netherlands; Department of Electrical Engineering, Eindhoven University of Technology, the Netherlands.
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Zhan Z, de Bock GH, van den Heuvel ER. Comparison of analysis methods and design choices for treatment-by-period interaction in unidirectional switch designs: a simulation study. BMC Med Res Methodol 2022; 22:294. [PMID: 36396984 PMCID: PMC9673415 DOI: 10.1186/s12874-022-01765-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 10/14/2022] [Indexed: 11/19/2022] Open
Abstract
Background Due to identifiability problems, statistical inference about treatment-by-period interactions has not been discussed for stepped wedge designs in the literature thus far. Unidirectional switch designs (USDs) generalize the stepped wedge designs and allow for estimation and testing of treatment-by-period interaction in its many flexible design forms. Methods Under different forms of the USDs, we simulated binary data at both aggregated and individual levels and studied the performances of the generalized linear mixed model (GLMM) and the marginal model with generalized estimation equations (GEE) for estimating and testing treatment-by-period interactions. Results The parallel group design had the highest power for detecting the treatment-by-period interactions. While there was no substantial difference between aggregated-level and individual-level analysis, the GLMM had better point estimates than the marginal model with GEE. Furthermore, the optimal USD for estimating the average treatment effect was not efficient for treatment-by-period interaction and the marginal model with GEE required a substantial number of clusters to yield unbiased estimates of the interaction parameters when the correlation structure is autoregressive of order 1 (AR1). On the other hand, marginal model with GEE had better coverages than GLMM under the AR1 correlation structure. Conclusion From the designs and methods evaluated, in general, parallel group design with a GLMM is, preferred for estimation and testing of treatment-by-period interaction in a clustered randomized controlled trial for a binary outcome. Supplementary Information The online version contains supplementary material available at 10.1186/s12874-022-01765-9.
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Almalik O, Zhan Z, van den Heuvel ER. Copas’ method is sensitive to different mechanisms of publication bias. Stat Probab Lett 2022. [DOI: 10.1016/j.spl.2022.109733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Varisco G, Peng Z, Kommers D, Zhan Z, Cottaar W, Andriessen P, Long X, van Pul C. Central apnea detection in premature infants using machine learning. Comput Methods Programs Biomed 2022; 226:107155. [PMID: 36215858 DOI: 10.1016/j.cmpb.2022.107155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 09/13/2022] [Accepted: 09/23/2022] [Indexed: 06/16/2023]
Abstract
BACKGROUND AND OBJECTIVE Apnea of prematurity is one of the most common diagnosis in neonatal intensive care units. Apneas can be classified as central, obstructive or mixed. According to the current international standards, minimal fluctuations or absence of fluctuations in the chest impedance (CI) suggest a central apnea (CA). However, automatic detection of reduced CI fluctuations leads to a high number of central apnea-suspected events (CASEs), the majority being false alarms. We aim to improve automatic detection of CAs by using machine learning to optimize detection of CAs among CASEs. METHODS Using an optimized algorithm for automated detection, all CASEs were detected in a population of 10 premature infants developing late-onset sepsis and 10 age-matched control patients. CASEs were inspected by two clinical experts and annotated as CAs or rejections in two rounds of annotations. A total of 47 features were extracted from the ECG, CI and oxygen saturation signals considering four 30 s-long moving windows, from 30 s before to 15 s after the onset of each CASE, using a moving step size of 5 s. Consecutively, new CA detection models were developed based on logistic regression with elastic net penalty, random forest and support vector machines. Performance was evaluated using both leave-one-patient-out and 10-fold cross-validation considering the mean area under the receiver-operating-characteristic curve (AUROC). RESULTS The CA detection model based on logistic regression with elastic net penalty returned the highest mean AUROC when features extracted from all four time windows were included, both using leave-one-patient-out and 10-fold cross-validation (mean AUROC of 0.88 and 0.90, respectively). Feature relevance was found to be the highest for features derived from the CI. A threshold for the false positive rate in the mean receiver-operating-characteristic curve equal to 0.3 led to a high percentage of correct detections for all CAs (78.2%) and even higher for CAs followed by a bradycardia (93.4%) and CAs followed by both a bradycardia and a desaturation (95.2%), which are more critical for the well-being of premature infants. CONCLUSIONS Models based on machine learning can lead to improved CA detection with fewer false alarms.
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Affiliation(s)
- Gabriele Varisco
- Applied Physics, Eindhoven University of Technology, Eindhoven, the Netherlands; Clinical Physics, Máxima Medical Center, Veldhoven, the Netherlands.
| | - Zheng Peng
- Applied Physics, Eindhoven University of Technology, Eindhoven, the Netherlands; Clinical Physics, Máxima Medical Center, Veldhoven, the Netherlands
| | - Deedee Kommers
- Applied Physics, Eindhoven University of Technology, Eindhoven, the Netherlands; Pediatrics, Máxima Medical Center, Veldhoven, the Netherlands
| | - Zhuozhao Zhan
- Mathematics and Computer Science, Eindhoven University of Technology, Eindhoven, the Netherlands
| | - Ward Cottaar
- Applied Physics, Eindhoven University of Technology, Eindhoven, the Netherlands
| | - Peter Andriessen
- Applied Physics, Eindhoven University of Technology, Eindhoven, the Netherlands; Pediatrics, Máxima Medical Center, Veldhoven, the Netherlands
| | - Xi Long
- Philips Research, Eindhoven, the Netherlands; Electrical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands.
| | - Carola van Pul
- Applied Physics, Eindhoven University of Technology, Eindhoven, the Netherlands; Clinical Physics, Máxima Medical Center, Veldhoven, the Netherlands
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Noben L, Lempersz C, van den Heuvel ER, Zhan Z, Vandenbussche FPHA, Coumans ABC, Haak MC, Vullings R, Oei SG, Clur SAB, van Laar JOEH. The electrical heart axis in fetuses with congenital heart disease, measured with non-invasive fetal electrocardiography. PLoS One 2022; 17:e0275802. [PMID: 36264863 PMCID: PMC9584524 DOI: 10.1371/journal.pone.0275802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 09/23/2022] [Indexed: 11/16/2022] Open
Abstract
OBJECTIVES To determine if the electrical heart axis in different types of congenital heart defects (CHD) differs from that of a healthy cohort at mid-gestation. METHODS Non-invasive fetal electrocardiography (NI-fECG) was performed in singleton pregnancies with suspected CHD between 16 and 30 weeks of gestation. The mean electrical heart axis (MEHA) was determined from the fetal vectorcardiogram after correction for fetal orientation. Descriptive statistics were used to determine the MEHA with corresponding 95% confidence intervals (CI) in the frontal plane of all fetuses with CHD and the following subgroups: conotruncal anomalies (CTA), atrioventricular septal defects (AVSD) and hypoplastic right heart syndrome (HRHS). The MEHA of the CHD fetuses as well as the subgroups was compared to the healthy control group using a spherically projected multivariate linear regression analysis. Discriminant analysis was applied to calculate the sensitivity and specificity of the electrical heart axis for CHD detection. RESULTS The MEHA was determined in 127 fetuses. The MEHA was 83.0° (95% CI: 6.7°; 159.3°) in the total CHD group, and not significantly different from the control group (122.7° (95% CI: 101.7°; 143.6°). The MEHA was 105.6° (95% CI: 46.8°; 164.4°) in the CTA group (n = 54), -27.4° (95% CI: -118.6°; 63.9°) in the AVSD group (n = 9) and 26.0° (95% CI: -34.1°; 86.1°) in the HRHS group (n = 5). The MEHA of the AVSD and the HRHS subgroups were significantly different from the control group (resp. p = 0.04 and p = 0.02). The sensitivity and specificity of the MEHA for the diagnosis of CHD was 50.6% (95% CI 47.5% - 53.7%) and 60.1% (95% CI 57.1% - 63.1%) respectively. CONCLUSION The MEHA alone does not discriminate between healthy fetuses and fetuses with CHD. However, the left-oriented electrical heart axis in fetuses with AVSD and HRHS was significantly different from the control group suggesting altered cardiac conduction along with the structural defect. TRIAL REGISTRATION Clinical trial registration number: NL48535.015.14.
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Affiliation(s)
- L. Noben
- Department of Obstetrics and Gynecology, Máxima Medical Center, Veldhoven, The Netherlands
- Eindhoven MedTech Innovation Center (e/MTIC), Eindhoven, The Netherlands
- * E-mail:
| | - C. Lempersz
- Department of Obstetrics and Gynecology, Máxima Medical Center, Veldhoven, The Netherlands
- Eindhoven MedTech Innovation Center (e/MTIC), Eindhoven, The Netherlands
| | - E. R. van den Heuvel
- Department of Mathematics and Computer Science, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Z. Zhan
- Department of Mathematics and Computer Science, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - F. P. H. A. Vandenbussche
- Department of Obstetrics and Gynecology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - A. B. C. Coumans
- Department of Obstetrics and Gynecology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - M. C. Haak
- Department of Obstetrics and Gynecology, Leiden University Medical Center, Leiden, The Netherlands
| | - R. Vullings
- Department of Obstetrics and Gynecology, Máxima Medical Center, Veldhoven, The Netherlands
- Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - S. G. Oei
- Department of Obstetrics and Gynecology, Máxima Medical Center, Veldhoven, The Netherlands
- Eindhoven MedTech Innovation Center (e/MTIC), Eindhoven, The Netherlands
- Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - S. A. B. Clur
- Department of Pediatric Cardiology, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - J. O. E. H. van Laar
- Department of Obstetrics and Gynecology, Máxima Medical Center, Veldhoven, The Netherlands
- Eindhoven MedTech Innovation Center (e/MTIC), Eindhoven, The Netherlands
- Department of Pediatric Cardiology, Amsterdam University Medical Centers, Amsterdam, The Netherlands
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12
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Almalik O, Zhan Z, van den Heuvel ER. Jointly pooling aggregated effect sizes and their standard errors from studies with continuous clinical outcomes. Biom J 2022; 64:1340-1360. [PMID: 35754152 PMCID: PMC9796109 DOI: 10.1002/bimj.202100108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 02/18/2022] [Accepted: 02/25/2022] [Indexed: 12/30/2022]
Abstract
The DerSimonian-Laird (DL) weighted average method for aggregated data meta-analysis has been widely used for the estimation of overall effect sizes. It is criticized for its underestimation of the standard error of the overall effect size in the presence of heterogeneous effect sizes. Due to this negative property, many alternative estimation approaches have been proposed in the literature. One of the earliest alternative approaches was developed by Hardy and Thompson (HT), who implemented a profile likelihood instead of the moment-based approach of DL. Others have further extended this likelihood approach and proposed higher-order likelihood inferences (e.g., Bartlett-type corrections). In addition, corrections factors for the estimated DL standard error, like the Hartung-Knapp-Sidik-Jonkman (HKSJ) adjustment, and the restricted maximum likelihood (REML) estimation have been suggested too. Although these improvements address the uncertainty in estimating the between-study variance better than the DL method, they all assume that the true within-study standard errors are known and equal to the observed standard errors of the effect sizes. Here, we will treat the observed standard errors as estimators for the within-study variability and we propose a bivariate likelihood approach that jointly estimates the overall effect size, the between-study variance, and the potentially heteroskedastic within-study variances. We study the performance of the proposed method by means of simulation, and compare it to DL (with and without HKSJ), HT, their higher-order likelihood methods, and REML. Our proposed approach seems to have better or similar coverages compared to the other approaches and it appears to be less biased in the case of heteroskedastic within-study variances when this heteroskedasticty is correlated with the effect size.
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Affiliation(s)
- Osama Almalik
- Department of Mathematics and Computer ScienceEindhoven University of TechnologyEindhovenThe Netherlands
| | - Zhuozhao Zhan
- Department of Mathematics and Computer ScienceEindhoven University of TechnologyEindhovenThe Netherlands
| | - Edwin R. van den Heuvel
- Department of Mathematics and Computer ScienceEindhoven University of TechnologyEindhovenThe Netherlands,Preventive Medicine and EpidemiologyDepartment of MedicineBoston UniversityUSA
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13
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Scholten AWJ, Zhan Z, Niemarkt HJ, Vervoorn M, van Leuteren RW, de Jongh FH, van Kaam AH, van den Heuvel ER, Hutten GJ. Multicentre paired non-inferiority study of the cardiorespiratory monitoring performance of the wireless and non-adhesive Bambi® belt measuring diaphragm activity in neonates: study protocol. BMJ Paediatr Open 2022; 6:10.1136/bmjpo-2022-001430. [PMID: 36053638 PMCID: PMC9185582 DOI: 10.1136/bmjpo-2022-001430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 04/26/2022] [Indexed: 11/04/2022] Open
Abstract
INTRODUCTION Cardiorespiratory monitoring is used in the neonatal intensive care unit (NICU) to assess the clinical status of newborn infants and detect critical deteriorations in cardiorespiratory function. Currently, heart rate (HR) is monitored by electrocardiography (ECG) and respiration by chest impedance (CI). Disadvantages of current monitoring techniques are usage of wired adhesive electrodes which may damage the skin and hinder care. The Bambi® belt is a wireless and non-adhesive alternative that enables cardiorespiratory monitoring by measuring electrical activity of the diaphragm via transcutaneous electromyography. A previous study showed feasibility of the Bambi® belt and this study compares the belt performance to ECG and CI. METHODS AND ANALYSIS This multicentre non-inferiority paired study will be performed in the NICU of the Máxima Medical Center (MMC) in Veldhoven and the Emma Children's Hospital, Amsterdam University Medical Centre (AmsterdamUMC) in Amsterdam, The Netherlands. 39 infants in different postmenstrual age groups (minimally 10 infants<30 weeks, between 30-32 weeks and >32 weeks) will be recruited. These infants will be monitored with the Bambi® belt in addition to standard ECG and CI for 24 hours. The primary outcome is the HR, studied with three criteria: (1) the limits of agreement of the HR measurements in terms of the second-to-second difference in the HR between the belt and standard ECG, (2) the detection of cardiac events consisting of bradycardia and tachycardia and (3) the quality of HR-monitoring. The secondary outcome is the respiratory rate (RR), studied with the criteria (1) agreement in RR-trend monitoring, (2) apnoea and tachypnoea detection and (3) reliable registrations. ETHICS AND DISSEMINATION This protocol was approved by the Medical Ethical Committee of the MMC and the Central Committee for Human Research. The MMC started patient recruitment in July and the AmsterdamUMC in August 2021. The results will be presented at conferences and published in peer-reviewed journals. TRIAL REGISTRATION NUMBER NL9480.
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Affiliation(s)
- Anouk W J Scholten
- Amsterdam UMC location University of Amsterdam, Department of Neonatology, Meibergdreef 9, Amsterdam, The Netherlands .,Amsterdam Reproduction & Development research institute, Amsterdam, The Netherlands
| | - Zhuozhao Zhan
- Eindhoven University of Technology, Department of Mathematics and Computer Science, Eindhoven, The Netherlands
| | - Hendrik J Niemarkt
- Máxima Medical Center, Department of Neonatology, Veldhoven, The Netherlands
| | - Marieke Vervoorn
- Máxima Medical Center, Department of Neonatology, Veldhoven, The Netherlands
| | - Ruud W van Leuteren
- Amsterdam UMC location University of Amsterdam, Department of Neonatology, Meibergdreef 9, Amsterdam, The Netherlands.,Amsterdam Reproduction & Development research institute, Amsterdam, The Netherlands
| | - Frans H de Jongh
- Amsterdam UMC location University of Amsterdam, Department of Neonatology, Meibergdreef 9, Amsterdam, The Netherlands.,University of Twente, Faculty of Science and Technology, Enschede, The Netherlands
| | - Anton H van Kaam
- Amsterdam UMC location University of Amsterdam, Department of Neonatology, Meibergdreef 9, Amsterdam, The Netherlands.,Amsterdam Reproduction & Development research institute, Amsterdam, The Netherlands
| | - Edwin R van den Heuvel
- Eindhoven University of Technology, Department of Mathematics and Computer Science, Eindhoven, The Netherlands
| | - G Jeroen Hutten
- Amsterdam UMC location University of Amsterdam, Department of Neonatology, Meibergdreef 9, Amsterdam, The Netherlands.,Amsterdam Reproduction & Development research institute, Amsterdam, The Netherlands
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14
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Affiliation(s)
- Edwin van den Heuvel
- Boston University, School of Medicine, Preventive Medicine and Epidemiology, 72 East Concorde Street, Boston 02118 MA, United States of America
- Eindhoven University of Technology, Department of Mathematics and Computer Science, Den Dolech 2, 5612 AZ Eindhoven, The Netherlands
| | - Zhuozhao Zhan
- Eindhoven University of Technology, Department of Mathematics and Computer Science, Den Dolech 2, 5612 AZ Eindhoven, The Netherlands
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15
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Varisco G, Kommers D, Long X, Zhan Z, Nano MM, Cottaar W, Andriessen P, Pul CV. Optimized Detection of Central Apneas Preceding Late-Onset Sepsis in Premature Infants. Annu Int Conf IEEE Eng Med Biol Soc 2021; 2021:5463-5468. [PMID: 34892362 DOI: 10.1109/embc46164.2021.9629528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
In neonatal intensive care units, respiratory traces of premature infants developing late onset sepsis (LOS) may also show episodes of apneas. However, since clinical patient monitors often underdetect apneas, clinical experts are required to investigate patients' traces looking for these events. In this work we present a method to optimize an existing algorithm for central apnea (CA) detection and how we used it together with human annotations to investigate the occurrence of CAs preceding LOS.The algorithm was optimized by using a previously-annotated dataset consisting of 90 hours, extracted from 10 premature infants. This allowed to double precision (19.7% vs 9.3%, median values per patient) without affecting recall (90.5% vs 94.5%) compared to the original algorithm. This choice caused the missed identification of just 1 additional CA (4 vs 3) in the whole dataset. The optimized algorithm was then used to annotate a second dataset consisting of 480 hours, extracted from 10 premature infants diagnosed with LOS. Annotations were corrected by two clinical experts.A significantly higher number of CA annotations was found in the 6 hours prior to sepsis onset (p-value < 0.05). The use of the optimized algorithm followed by human annotations proved to be a suitable, time-efficient method to annotate CAs before sepsis in premature infants, enabling future use in large datasets.
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16
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Zhan Z, Bastide-Van Gemert SL, Wiersum M, Heineman KR, Hadders-Algra M, Heuvel ERVD. A comparison of statistical methods for age-specific reference values of discrete scales. COMMUN STAT-SIMUL C 2021. [DOI: 10.1080/03610918.2021.1977824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Z. Zhan
- Mathematics and Computer Science, Technische Universiteit Eindhoven, Eindhoven, Netherlands
| | | | - M. Wiersum
- Paediatrics, Universitair Medisch Centrum Groningen – UMCG, Groningen, Netherlands
| | - K. R. Heineman
- Paediatrics, Universitair Medisch Centrum Groningen – UMCG, Groningen, Netherlands
| | - M. Hadders-Algra
- Obstetrics and Gynaecology, Universitair Medisch Centrum Groningen – UMCG, Groningen, Netherlands
| | - E. R. van den Heuvel
- Mathematics and Computer Science, Technische Universiteit Eindhoven, Eindhoven, Netherlands
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17
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Almalik O, Zhan Z, van den Heuvel ER. Tests for publication bias are unreliable in case of heteroscedasticity. Contemp Clin Trials Commun 2021; 22:100781. [PMID: 34179565 PMCID: PMC8209747 DOI: 10.1016/j.conctc.2021.100781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 04/16/2021] [Accepted: 04/28/2021] [Indexed: 10/25/2022] Open
Abstract
Regression based methods for the detection of publication bias in meta-analysis have been extensively evaluated in literature. When dealing with continuous outcomes, specific hidden factors (e.g., heteroscedasticity) may interfere with the test statistics. In this paper we investigate the influence of residual heteroscedasticity on the performance of four tests for publication bias: the Egger test, the Begg-Mazumdar test and two tests based on weighted regression. In the presence of heteroscedasticity, the Egger test and the weighted regression tests highly inflate the Type I error rate, while the Begg-Mazumdar test deflates the Type I error rate. Although all three tests already have low statistical power, heteroscedasticity typically reduces it further. Our results in combination with earlier discussions on publication bias tests lead us to conclude that application of these tests on continuous treatment effects is not warranted.
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Affiliation(s)
- Osama Almalik
- Department of Mathematics and Computer Science, Eindhoven University of Technology, Eindhoven, the Netherlands
| | - Zhuozhao Zhan
- Department of Mathematics and Computer Science, Eindhoven University of Technology, Eindhoven, the Netherlands
| | - Edwin R van den Heuvel
- Department of Mathematics and Computer Science, Eindhoven University of Technology, Eindhoven, the Netherlands.,Department of Preventive Medicine and Epidemiology, School of Medicine, Boston University, Boston, USA
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18
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Chen Y, Hong X, Liu L, Zhan Z, Li X, Pu C, Chen S, Liao S. [Anatomy of the deep circumflex iliac artery perforators and reconstruction of complex mandibular defects with chimeric deep circumflex iliac artery perforator flap]. Nan Fang Yi Ke Da Xue Xue Bao 2021; 41:754-759. [PMID: 34134964 DOI: 10.12122/j.issn.1673-4254.2021.05.17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
OBJECTIVE To investigate the anatomy of the perforator vessels of the deep circumflex iliac artery (DCIA) and the techniques for repairing mandibular complex defect using chimeric deep circumflex iliac artery perforator flap (DCIAPF). OBJECTIVE We analyzed the origin, distribution, number and courses of the perforator vessels of the DCIA, and measured the outside diameters of the vessels at the origin in 6 adult cadaveric specimens (12 sides) with latex perfusion. From July, 2018 to September, 2019, based on the results of anatomical study and imaging findings and using the digital surgical guide plate, we harvested DCIAPF from 4 patients for repairing mandibular body or angle defects and oral soft tissue defects. OBJECTIVE The perforating vessels of the DCIA included abdominal muscular branches, osteomusculocutaneous branches and terminal musculocutaneous branches. The abdominal muscle branches originated from the DCIA inguinal segment in 4 and from both the inguinal and iliac segments in 2 of the specimens. The osteomusculocutaneous branches all originated from the internal iliac crest in 75% and from both the inguinal and internal iliac crest segments in 25% of cases; the inguinal segment gave rise to only one perforating branch. The number of the musculocutaneous perforating branches was 1 (58.3%) or 2 (41.7%). In the 4 patients undergoing mandibular reconstruction, the DCIAPF survived in all cases with good recovery of the donor site wound. Satisfactory facial appearance with good oral morphology and occlusal relationship was achieved at 1 month postoperatively in all the patients. None of the patients experienced obvious functional abnormalities at the donor site, and imaging examination confirmed successful reconstruction of the oromandibular defects in all the cases. OBJECTIVE A good understanding of the anatomic characteristics of the perforator vessels of the DCIA combined with imaging examinations and digital surgery technology facilitates the harvest of DCIAPF for repairing mandibular body or angle defects complicated by oral soft tissue defects.
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Affiliation(s)
- Y Chen
- Department of Stomatology, First Affiliated Hospital of Bengbu Medical College, Bengbu 233004, China
| | - X Hong
- Department of Stomatology, First Affiliated Hospital of Bengbu Medical College, Bengbu 233004, China
| | - L Liu
- Department of Stomatology, First Affiliated Hospital of Bengbu Medical College, Bengbu 233004, China
| | - Z Zhan
- Department of Stomatology, First Affiliated Hospital of Bengbu Medical College, Bengbu 233004, China
| | - X Li
- Department of Stomatology, First Affiliated Hospital of Bengbu Medical College, Bengbu 233004, China
| | - C Pu
- Department of Ultrasonic Medicine, First Affiliated Hospital of Bengbu Medical College, Bengbu 233004, China
| | - S Chen
- Department of Anatomy, Bengbu Medical College, Bengbu 233030, China
| | - S Liao
- Department of Stomatology, First Affiliated Hospital of Bengbu Medical College, Bengbu 233004, China
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19
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Varisco G, Mortel H, Cabrera‐Quiros L, Atallah L, Hueske‐Kraus D, Long X, Cottaar EJE, Zhan Z, Andriessen P, Pul C. Optimisation of clinical workflow and monitor settings safely reduces alarms in the NICU. Acta Paediatr 2021; 110:1141-1150. [PMID: 33048364 PMCID: PMC7983880 DOI: 10.1111/apa.15615] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 09/16/2020] [Accepted: 10/07/2020] [Indexed: 11/29/2022]
Abstract
Aim To address alarm fatigue, a new alarm management system which ensures a quicker delivery of alarms together with waveform information on nurses' handheld devices was implemented and settings optimised. The effects of this clinical implementation on alarm rates and nurses' responsiveness were measured in an 18‐bed single family rooms neonatal intensive care unit (NICU). Methods The technical implementation of the alarm management system was followed by clinical workflow optimisation. Alarms and vital parameters from October 2017 to December 2019 were analysed. Measures included monitoring alarms, nurses' response to alarms and time spent by patients in different saturation ranges. A survey among nurses was performed to evaluate changes in alarm rate and use of protocols. Results A significant reduction of monitoring alarms per patient days was detected after the optimisation phase (in particular for SpO2 ≤ 80%, P < .001). More time was spent by infants within the optimal peripheral oxygen saturation range (88% < SpO2 < 95%, P < .001). Results from the surveys showed that false alarms are less likely to cause an inappropriate response after the optimisation phase. Conclusion The implementation of an alarm management solution and an optimisation programme can safely reduce the alarm burden inside of the NICU environment.
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Affiliation(s)
- Gabriele Varisco
- Applied Physics Eindhoven University of Technology Eindhoven The Netherlands
- Clinical Physics Máxima Medical Center Veldhoven The Netherlands
| | - Heidi Mortel
- Pediatrics Máxima Medical Center Veldhoven The Netherlands
| | - Laura Cabrera‐Quiros
- Applied Physics Eindhoven University of Technology Eindhoven The Netherlands
- Clinical Physics Máxima Medical Center Veldhoven The Netherlands
| | | | | | - Xi Long
- Philips Research Eindhoven The Netherlands
- Electrical Engineering Eindhoven University of Technology Eindhoven The Netherlands
| | - Eduardus JE Cottaar
- Applied Physics Eindhoven University of Technology Eindhoven The Netherlands
| | - Zhuozhao Zhan
- Mathematics and Computer Science Eindhoven University of Technology Eindhoven The Netherlands
| | - Peter Andriessen
- Applied Physics Eindhoven University of Technology Eindhoven The Netherlands
- Pediatrics Máxima Medical Center Veldhoven The Netherlands
| | - Carola Pul
- Applied Physics Eindhoven University of Technology Eindhoven The Netherlands
- Clinical Physics Máxima Medical Center Veldhoven The Netherlands
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20
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Post RAJ, Regis M, Zhan Z, van den Heuvel ER. How did governmental interventions affect the spread of COVID-19 in European countries? BMC Public Health 2021; 21:411. [PMID: 33637062 PMCID: PMC7908011 DOI: 10.1186/s12889-021-10257-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 01/17/2021] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND To reduce the transmission of the severe acute respiratory syndrome coronavirus 2 in its first wave, European governments have implemented successive measures to encourage social distancing. However, it remained unclear how effectively measures reduced the spread of the virus. We examined how the effective-contact rate (ECR), the mean number of daily contacts for an infectious individual to transmit the virus, among European citizens evolved during this wave over the period with implemented measures, disregarding a priori information on governmental measures. METHODS We developed a data-oriented approach that is based on an extended Susceptible-Exposed-Infectious-Removed (SEIR) model. Using the available data on the confirmed numbers of infections and hospitalizations, we first estimated the daily total number of infectious-, exposed- and susceptible individuals and subsequently estimated the ECR with an iterative Poisson regression model. We then compared change points in the daily ECRs to the moments of the governmental measures. RESULTS The change points in the daily ECRs were found to align with the implementation of governmental interventions. At the end of the considered time-window, we found similar ECRs for Italy (0.29), Spain (0.24), and Germany (0.27), while the ECR in the Netherlands (0.34), Belgium (0.35) and the UK (0.37) were somewhat higher. The highest ECR was found for Sweden (0.45). CONCLUSIONS There seemed to be an immediate effect of banning events and closing schools, typically among the first measures taken by the governments. The effect of additionally closing bars and restaurants seemed limited. For most countries a somewhat delayed effect of the full lockdown was observed, and the ECR after a full lockdown was not necessarily lower than an ECR after (only) a gathering ban.
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Affiliation(s)
- Richard A J Post
- Department of Mathematics and Computer science, Eindhoven University of Technology, P.O. Box 513, 5600, MB, Eindhoven, The Netherlands
| | - Marta Regis
- Department of Mathematics and Computer science, Eindhoven University of Technology, P.O. Box 513, 5600, MB, Eindhoven, The Netherlands
| | - Zhuozhao Zhan
- Department of Mathematics and Computer science, Eindhoven University of Technology, P.O. Box 513, 5600, MB, Eindhoven, The Netherlands
| | - Edwin R van den Heuvel
- Department of Mathematics and Computer science, Eindhoven University of Technology, P.O. Box 513, 5600, MB, Eindhoven, The Netherlands. .,Department of Preventive Medicine and Epidemiology, School of Medicine, Boston University, Boston, MA, 02118, USA.
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21
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Cabrera-Quiros L, Varisco G, Zhan Z, Long X, Andriessen P, Cottaar EJE, van Pul C. Estimation of Heart Rate Directly from ECG Spectrogram in Neonate Intensive Care Units. Annu Int Conf IEEE Eng Med Biol Soc 2020; 2020:320-323. [PMID: 33017993 DOI: 10.1109/embc44109.2020.9176176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This paper presents a simple yet novel method to estimate the heart frequency (HF) of neonates directly from the ECG signal, instead of using the RR-interval signals as generally done in clinical practices. From this, the heart rate (HR) can be derived. Thus, we avoid the use of peak detectors and the inherent errors that come with them.Our method leverages the highest Power Spectral Densities (PSD) of the ECG, for the bins around the frequencies related to heart rates for neonates, as they change in time (spectrograms).We tested our approach with the monitoring data of 6 days for 52 patients in a Neonate Intensive Care Unit (NICU) and compared against the HR from a commercial monitor, which produced a sample every second. The comparison showed that 92.4% of the samples have a difference lower than 5bpm. Moreover, we obtained a median MAE (Mean Absolute Error) between subjects equal to 2.28 bpm and a median RMSE (Root Mean Square Error) equal to 5.82 bpm. Although tested for neonates, we hypothesize that this method can also be customized for other populations.Finally, we analyze the failure cases of our method and found a direct co-allocation of errors due to moments with higher PSD in the lower frequencies with the presence of critical alarms related to other physiological systems (e.g. desaturation).
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22
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Zhan Z, den Heuvel ER. Correction for “Optimal unidirectional switch designs” by Zhuozhao Zhan, Geertruida H. de Bock, and Edwin R. van den Heuvel. Stat Med 2020; 39:2587. [DOI: 10.1002/sim.8553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 03/02/2020] [Indexed: 11/06/2022]
Affiliation(s)
- Zhuozhao Zhan
- Department of Mathematics and Computer ScienceEindhoven University of Technology Eindhoven Netherlands
| | - Edwin R. den Heuvel
- Department of Mathematics and Computer ScienceEindhoven University of Technology Eindhoven Netherlands
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23
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van den Heuvel ER, van Driel SAW, Zhan Z. A bivariate zero-inflated Poisson control chart: Comments and corrections on earlier results. COMMUN STAT-THEOR M 2020. [DOI: 10.1080/03610926.2020.1736304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Edwin R. van den Heuvel
- Department of Mathematics and Computer Science, Eindhoven University of Technology, Eindhoven, Netherlands
| | - Stephan A. W. van Driel
- Department of Mathematics and Computer Science, Eindhoven University of Technology, Eindhoven, Netherlands
| | - Zhuozhao Zhan
- Department of Mathematics and Computer Science, Eindhoven University of Technology, Eindhoven, Netherlands
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Chen D, Yuan S, Lao M, Zhan Y, Xu H, Liang L, Cai X, Wang X, Zhan Z. Umbilical arterial Doppler ultrasonography predicts late pregnancy outcomes in patients with lupus nephritis: a multicenter study from southern China. Lupus 2019; 28:1312-1319. [PMID: 31495267 DOI: 10.1177/0961203319873702] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVES To investigate the fetal adverse pregnancy outcomes (APOs) and the predictive value of umbilical arterial Doppler ultrasonography in the third trimester in pregnant women with lupus nephritis (LN). METHODS A retrospective cohort study enrolling 203 LN patients from 2007 to 2017 was performed. Ultrasonic parameters were recorded. RESULTS Fetal APOs occurred in 103 patients (103/203, 50.7%). Sixty-six pregnancies (66/203, 32.5%) ended with preterm births. The incidence rate of intrauterine growth restriction (IUGR) was 18.2% (37/203). Fetal distress was noted in 23 pregnancies (23/203, 11.3%). All the Doppler parameters elevated in patients with IUGR, fetal distress, and composite conditions. Resistance index (RI) indicated the highest risk of IUGR and composite APOs. The cutoff values were 0.66 and 0.67, respectively. Sensitivities were 51.4% and 33.7%, and specificities were 87.4% and 92.1%. Peak velocity of the umbilical arteries at end-systole (Vmax, abbreviated as S) to that at end-diastole (Vmin, abbreviated as D) (S/D) ratio was also a best predictor for IUGR, with the optimal cutoff value of 2.88. Sensitivity and specificity were comparable with RI. Pulsatility index (PI) over 0.84 was an ideal indicator for fetal distress with an optimal combination of sensitivity (89.5%) and specificity (51.6%). CONCLUSIONS Fetal complications were frequent in patients with LN. Umbilical arterial Doppler ultrasonography was a useful measure to predict late IUGR, fetal distress, and the composite APOs.
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Affiliation(s)
- D Chen
- Department of Rheumatology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - S Yuan
- Department of Rheumatology, South China University of Technology, Guangzhou, China
| | - M Lao
- Department of Rheumatology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.,Department of Geriatrics, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Y Zhan
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - H Xu
- Department of Rheumatology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - L Liang
- Department of Rheumatology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - X Cai
- Department of Rheumatology, South China University of Technology, Guangzhou, China
| | - X Wang
- Department of Ultrasound, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Z Zhan
- Department of Rheumatology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
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Abstract
Nonalcoholic fatty liver disease (NAFLD) includes nonalcoholic simple fatty liver, nonalcoholic steatohepatitis, liver cirrhosis, and liver cancer and is the most common liver disease in the world. The complex pathogenesis of NAFLD is a major concern among researchers. CD36 is a transmembrane glycoprotein that takes up fatty acid and binds to oxidized low-density lipoprotein in the liver, and therefore, it is involved in the development and progression of NAFLD. With reference to the latest research findings, this article reviews the association between CD36 and NAFLD and the role of CD36.
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Affiliation(s)
- Z Zhan
- Department of Infectious Diseases, Institute for Viral Hepatitis, the Key Laboratory of Molecular Biology for Infectious Diseases, Chinese Ministry of Education, the Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
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Lao M, Wang X, Ding M, Yang Z, Chen H, Liang L, Zhan Z, Chen D. Invasive fungal disease in patients with systemic lupus erythematosus from Southern China: a retrospective study. Lupus 2018; 28:77-85. [PMID: 30526329 DOI: 10.1177/0961203318817118] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Objective To investigate the characteristics and associated factors of invasive fungal disease in patients with systemic lupus erythematosus from Southern China. Methods A retrospective study was performed. Demographic and clinical characteristics, laboratory data, and radiographic manifestations were recorded. Results A total of 45 lupus patients with invasive fungal disease (incidence 1.1%) were included. Twenty-three cases (51.1%) were infected with mold and 22 cases (48.9%) with yeast. Aspergillus spp. (44.4%) and Cryptococcus spp. (33.3%) were common. Aspergillosis mainly occurred in the lung. Cryptococcosis developed in the lung (40.0%), meninges (46.7%) and bloodstream (13.3%). Compared with yeast infection, mold infection tended to develop in patients with active lupus nephritis (65.2% vs. 31.8%, P = 0.03) and the mortality rate was higher (20.0% vs. 0%, P = 0.001). Co-infection with bacteria, virus or superficial fungi occurred in 12 patients (26.7%). Multivariate logistic regression analysis indicated that lymphopenia (odds ratio 2.65, 95% confidential interval 1.14–6.20, P = 0.02) and an accumulated dose of glucocorticoid (odds ratio 1.58, 95% confidence interval 1.10–2.25, P = 0.01) was associated with invasive fungal disease in lupus patients. Conclusion Mold infection tended to develop in patients with active lupus disease with high mortality. Co-infection is not rare. Lymphopenia and an accumulated dose of glucocorticoid are associated with invasive fungal disease in lupus patients.
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Affiliation(s)
- M. Lao
- Department of Rheumatology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
- Department of Geriatrics, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - X. Wang
- Department of Ultrasound, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - M. Ding
- Department of Geriatrics, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Z. Yang
- Department of Pathology, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China
| | - H. Chen
- Department of Respirology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - L. Liang
- Department of Rheumatology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Z. Zhan
- Department of Rheumatology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - D. Chen
- Department of Rheumatology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
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Zhan Z, de Bock GH, van den Heuvel ER. Optimal unidirectional switch designs. Stat Med 2018; 37:3573-3588. [PMID: 30003557 DOI: 10.1002/sim.7853] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 05/16/2018] [Accepted: 05/31/2018] [Indexed: 11/07/2022]
Abstract
Stepped wedge designs and delayed start designs can all be considered as special cases of the so-called unidirectional switch design. This paper provides optimal proportions of clusters that are allocated to switch patterns in a unidirectional switch design to minimize the asymptotic variance of the treatment effect estimator. This unique optimal design applies to certain cross-sectional and longitudinal variance component models. When the intraclass correlation coefficient is zero, the optimal unidirectional switch design coincides with the classic (cluster) parallel group design. The optimal unidirectional switch design is more efficient than the optimal stepped wedge design and delayed start designs. Compared with the uniform unidirectional switch design, the efficiency gain of the optimal unidirectional switch design can be substantial, but it depends on the intraclass correlation and the cluster size. We also showed that augmenting the optimal stepped wedge design with pure control pattern is more efficient than the optimal stepped wedge design. In addition, robust minimax design for unidirectional switch design, delayed start design, and stepped wedge design are provided.
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Affiliation(s)
- Zhuozhao Zhan
- Department of Mathematics and Computer Science, Eindhoven University of Technology, Eindhoven, The Netherlands.,Department of Epidemiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Geertruida H de Bock
- Department of Epidemiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Edwin R van den Heuvel
- Department of Mathematics and Computer Science, Eindhoven University of Technology, Eindhoven, The Netherlands
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Singh SC, Li H, Yao C, Zhan Z, Yu W, Yu Z, Guo C. Structural and compositional control in copper selenide nanocrystals for light-induced self-repairable electrodes. Nano Energy 2018; 51:774-785. [PMID: 30177955 PMCID: PMC6100260 DOI: 10.1016/j.nanoen.2018.07.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
In nature, self-healing can be induced by sunlight for damage and wound repair, and this phenomenon is very important to living species for prolonging their lives. This self-repairing feature is obviously highly desirable for non-biological materials and manmade systems. In this paper, we demonstrate, for the first time, that battery electrodes can be self-repaired when exposed to sunlight. Here, we show that the optical, and photoelectrochemical (PEC) properties can be controlled by varying structural and compositional parameters of copper selenide nanocrystals (NCs). Cation to anion ratio in copper selenide (Cu2±xSe) NCs can be controlled over a wide range of 1.3-2.7 by simply changing the reaction temperature and impurity. Light-induced self-repairable behavior is demonstrated with electrochemical (EC) and PEC performances of electrodes made with stoichiometric copper selenide NCs. This nature-inspired, self-repairing behavior can be applied to batteries, supercapacitors, and photo-electrochemical fuel generators.
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Affiliation(s)
- Subhash C. Singh
- The Institute of Optics, University of Rochester, New York 14627, United States
- Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP), Changchun, China
| | - Huiyan Li
- The Institute of Optics, University of Rochester, New York 14627, United States
| | - Chaonan Yao
- Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP), Changchun, China
| | - Z. Zhan
- The Institute of Optics, University of Rochester, New York 14627, United States
| | - Weili Yu
- Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP), Changchun, China
| | - Zhi Yu
- Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP), Changchun, China
| | - Chunlei Guo
- The Institute of Optics, University of Rochester, New York 14627, United States
- Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP), Changchun, China
- Corresponding author at: The Institute of Optics, University of Rochester, New York 14627, United States.
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Koleva-Kolarova R, De Jonge C, Abu Hantash M, Zhan Z, Postema E, Feenstra T, Pijnappel R, Greuter M, De Bock G. A modelling study to evaluate the costs and effects of lowering the starting age of population breast cancer screening. Eur J Cancer 2018. [DOI: 10.1016/s0959-8049(18)30274-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Zhang Y, Hu S, Zhou JY, Sun HS, Zhang H, Zheng Z, Zhu XD, Li GR, Gui XM, Zhan Z, Jin DH. Design and performance testing of an axial-flow ventricular assist device developed at the Fu Wai Hospital in Beijing. Int J Artif Organs 2018; 31:983-7. [PMID: 19089800 DOI: 10.1177/039139880803101108] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Purpose Various ventricular assist devices (VADs) have been developed for clinical use in recent years. The aim of a multidisciplinary research team at the Fuwai Hospital of the Peking Union Medical College is to design and develop an axial flow left ventricular assist device (LVAD) for adults. Methods Using Computational Fluid Dynamics (CFD), the inflow characteristics of the axial flow pump were analyzed. After CFD analysis, the axial pump was fabricated using a 5-axis, computer numerical control (CNC) milling machine. Performances of the pump both in vitro and in vivo were tested. Results This VAD, which was developed after numerous CFD analyses for the flow characteristics of the pump, is 58.5 mm long, 30 mm wide and weighs 120 g. The pump can deliver 5 lpm for pressures of 100 mmHg over 8500 rpm. The NIH value was 0.01 g/100 L. The hemolysis, which was evaluated in an in vivo test, was a bit higher than the normal value, but remained within an acceptable range. Conclusions Performance of the pump in vitro and in vivo was considered sufficient for an LVAD. Further design improvements are being undertaken in terms of hemolysis and thrombosis to improve the biocompatibility of the pump.
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Affiliation(s)
- Y. Zhang
- Research Center for Cardiovascular Regenerative Medicine, Fu Wai Hospital, Beijing - China
- Department of Cardiovascular Surgery, Fu Wai Hospital, Beijing - China
| | - S.S. Hu
- Research Center for Cardiovascular Regenerative Medicine, Fu Wai Hospital, Beijing - China
- Department of Cardiovascular Surgery, Fu Wai Hospital, Beijing - China
| | - J.-Y. Zhou
- Research Center for Cardiovascular Regenerative Medicine, Fu Wai Hospital, Beijing - China
| | - H.-S. Sun
- Department of Cardiovascular Surgery, Fu Wai Hospital, Beijing - China
| | - H. Zhang
- Research Center for Cardiovascular Regenerative Medicine, Fu Wai Hospital, Beijing - China
- Department of Cardiovascular Surgery, Fu Wai Hospital, Beijing - China
| | - Z. Zheng
- Research Center for Cardiovascular Regenerative Medicine, Fu Wai Hospital, Beijing - China
- Department of Cardiovascular Surgery, Fu Wai Hospital, Beijing - China
| | - X.-D. Zhu
- Department of Cardiovascular Surgery, Fu Wai Hospital, Beijing - China
| | - G.-R. Li
- Research Center for Cardiovascular Regenerative Medicine, Fu Wai Hospital, Beijing - China
- Department of Cardiovascular Surgery, Fu Wai Hospital, Beijing - China
| | - X.-M. Gui
- School of Jet Propulsion, Beijing University of Aeronautics and Astronautics, Beijing - China
| | - Z. Zhan
- School of Jet Propulsion, Beijing University of Aeronautics and Astronautics, Beijing - China
| | - D.-H. Jin
- School of Jet Propulsion, Beijing University of Aeronautics and Astronautics, Beijing - China
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Zhan Z, Verberne CJ, van den Heuvel ER, Grossmann I, Ranchor AV, Wiggers T, de Bock GH. Psychological effects of the intensified follow-up of the CEAwatch trial after treatment for colorectal cancer. PLoS One 2017; 12:e0184740. [PMID: 28922422 PMCID: PMC5603155 DOI: 10.1371/journal.pone.0184740] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 08/25/2017] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND The aim of the study was to evaluate psychological effects of the state-of-art intensified follow-up protocol for colorectal cancer patients in the CEAwatch trial. METHOD At two time points during the CEAwatch trial questionnaires regarding patients' attitude towards follow-up, patients' psychological functioning and patients' experiences and expectations were sent to participants by post. Linear mixed models were fitted to assess the influences and secular trends of the intensified follow-up on patients' attitude towards follow-up and psychological functioning. As secondary outcome, odds ratios were calculated using ordinal logistic mixed model to compare patients' experiences to their expectations, as well as their experiences at two different time points. RESULTS No statistical significant effects of the intensified follow-up were found on patients' attitude towards the follow-up and psychological functioning variables. Patients had high expectations of the intensified follow-up and their experiences at the second time point were more positive compared to the scores at the first time point. CONCLUSION The intensified follow-up protocol posed no adverse effects on patients' attitude towards follow-up and psychological functioning. In general, patients were more nervous and anxious at the start of the new follow-up protocol, had high expectations of the new follow-up protocol and were troubled by the nuisances of the blood sample testing. As they spent more time in the follow-up and became more adapted to it, the nervousness and anxiety decreased and the preference for the frequent blood test became high in replacement of conversations with the doctors.
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Affiliation(s)
- Zhuozhao Zhan
- Department of Epidemiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Charlotte J. Verberne
- Department of Surgery, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Edwin R. van den Heuvel
- Department of Epidemiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- Department of Mathematics and Computer Science, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Irene Grossmann
- Department of Surgery, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- Department of Surgery afd. P, Aarhus University Hospital, Aarhus, Denmark
| | - Adelita V. Ranchor
- Department of Health Sciences, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Theo Wiggers
- Department of Surgery, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Geertruida H. de Bock
- Department of Epidemiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
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Long YL, Pan WZ, Zhan Z, Jin QC, Zhou DX. [Analysis of pulmonary valve function in patients with tetralogy of Fallot after radical surgery]. Zhonghua Xin Xue Guan Bing Za Zhi 2017; 45:722-725. [PMID: 28851192 DOI: 10.3760/cma.j.issn.0253-3758.2017.08.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To analyze the pulmonary valve function in patients with tetralogy of Fallot after radical surgery. Methods: Clinical data of 263 patients (119 male, mean age (33.2±11.5) years old) with tetralogy of Fallot underwent radical surgery in our hospital from January 2010 to June 2016 were retrospectively analyzed. According to age, patients were divided into 14-17 years old group (14 cases), 18-29 years old group (100 cases), 30-39 years old group (61 cases) and above 40 years old group (87 cases). The patients were divided into pulmonary regurgitation group (87 cases) and control group (176 cases) according to weather they have moderate or severe pulmonary regurgitation. Echocardiographic data were compared among groups. Results: A total of 83 patients received re-operation. The median age of the primary radical operation was 9 (5, 13) years, and the median time from the primary radical operation to echocardiographic follow-up was 5 (1, 13) years. Among the 263 enrolled patients, prevalence of pulmonary regurgitation was 36.1% (95/263), and pulmonary stenosis was evidenced in 28 patients (10.6%). The ratio of moderate to severe tricuspid regurgitation was 14.3% (2/14), 27.0% (27/100), 32.8% (20/61) and 37.9% (33/87) in 14-17 years old group, 18-29 years old group, 30-39 years old group and above 40 years old group, respectively (P=0.029), while prevalence of moderate and severe pulmonary regurgitation, moderate and severe pulmonary valve stenosis, pulmonary valve transvalvular pressure >40 mmHg (1 mmHg=0.133 kPa), right atrial and right ventricular enlargement ratio were similar among groups (all P>0.05). The ratio of moderate and severe tricuspid regurgitation and right ventricular enlargement in the pulmonary regurgitation group was significantly higher than in the control group (40.2% (35/87) vs. 27.3% (48/176) and 96.6% (84/87) vs. 87.5% (154/176), all P<0.05), while left ventricular ejection fraction, right atrial enlargement, and right ventricular wall thickness were similar between the two groups (all P>0.05). Conclusion: Pulmonary regurgitation is a common clinical feature among survivors of tetralogy of Fallot patients after radical surgery, and moderate to severe pulmonary regurgitation increases the risk of tricuspid regurgitation and enlargement of the right ventricle.
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Affiliation(s)
- Y L Long
- Department of Cardiology, Shanghai Institute of cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai 200032, China
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Verberne CJ, Zhan Z, van den Heuvel ER, Oppers F, de Jong AM, Grossmann I, Klaase JM, de Bock GH, Wiggers T. Survival analysis of the CEAwatch multicentre clustered randomized trial. Br J Surg 2017; 104:1069-1077. [PMID: 28376235 DOI: 10.1002/bjs.10535] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 11/30/2016] [Accepted: 02/08/2017] [Indexed: 01/09/2023]
Abstract
BACKGROUND The CEAwatch randomized trial showed that follow-up with intensive carcinoembryonic antigen (CEA) monitoring (CEAwatch protocol) was better than care as usual (CAU) for early postoperative detection of colorectal cancer recurrence. The aim of this study was to calculate overall survival (OS) and disease-specific survival (DSS). METHODS For all patients with recurrence, OS and DSS were compared between patients detected by the CEAwatch protocol versus CAU, and by the method of detection of recurrence, using Cox regression models. RESULTS Some 238 patients with recurrence were analysed (7·5 per cent); a total of 108 recurrences were detected by CEA blood test, 64 (55·2 per cent) within the CEAwatch protocol and 44 (41·9 per cent) in the CAU group (P = 0·007). Only 16 recurrences (13·8 per cent) were detected by patient self-report in the CEAwatch group, compared with 33 (31·4 per cent) in the CAU group. There was no significant improvement in either OS or DSS with the CEAwatch protocol compared with CAU: hazard ratio 0·73 (95 per cent 0·46 to 1·17) and 0·78 (0·48 to 1·28) respectively. There were no differences in survival when recurrence was detected by CT versus CEA measurement, but both of these methods yielded better survival outcomes than detection by patient self-report. CONCLUSION There was no direct survival benefit in favour of the intensive programme, but the CEAwatch protocol led to a higher proportion of recurrences being detected by CEA-based blood test and reduced the number detected by patient self-report. This is important because detection of recurrence by blood test was associated with significantly better survival than patient self-report, indirectly supporting use of the CEAwatch protocol.
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Affiliation(s)
- C J Verberne
- Departments of Surgery, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands
| | - Z Zhan
- Departments of Epidemiology, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands
| | - E R van den Heuvel
- Departments of Epidemiology, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands.,Department of Mathematics and Computer Science, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - F Oppers
- Departments of Epidemiology, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands
| | - A M de Jong
- Departments of Epidemiology, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands
| | - I Grossmann
- Departments of Surgery, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands.,Department of Gastrointestinal Surgery, Aarhus University Hospital, Aarhus, Denmark
| | - J M Klaase
- Department of Surgery, Medical Spectrum Twente, Enschede, The Netherlands
| | - G H de Bock
- Departments of Epidemiology, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands
| | - T Wiggers
- Departments of Surgery, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands
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van der Sluis FJ, Zhan Z, Verberne CJ, Muller Kobold AC, Wiggers T, de Bock GH. Predictive performance of TPA testing for recurrent disease during follow-up after curative intent surgery for colorectal carcinoma. Clin Chem Lab Med 2017; 55:269-274. [PMID: 27522097 DOI: 10.1515/cclm-2016-0207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2016] [Accepted: 07/14/2016] [Indexed: 11/15/2022]
Abstract
BACKGROUND The aim of the present study was to investigate the predictive performance of serial tissue polypeptide antigen (TPA) testing after curative intent resection for detection of recurrence of colorectal malignancy. METHODS Serum samples were obtained in 572 patients from three different hospitals during follow-up after surgery. Test characteristics of serial TPA testing were assessed using a cut-off value of 75 U/L. The relation with American Joint Committee on Cancer stage and the potential additive value of tissue polypeptide antigen testing upon standard carcinoembryonic antigen (CEA) testing were investigated. RESULTS The area under the receiver operating characteristic curve of TPA for recurrent disease was 0.70, indicating marginal usefulness as a predictive test. Forty percent of cases that were detected by CEA testing would have been missed by TPA testing alone, whilst most cases missed by CEA were also not detected by TPA testing. In the subpopulation of patients with stage III disease predictive performance was good (area under the curve 0.92 within 30 days of diagnosing recurrent disease). In this group of patients, 86% of cases that were detected by CEA were also detected by TPA. CONCLUSIONS Overall, TPA is a relatively poor predictor for recurrent disease during follow-up. When looking at the specific subpopulation of patients with stage III disease predictive performance of TPA was good. However, TPA testing was not found to be superior to CEA testing in this specific subpopulation.
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Abstract
Clinical trials may apply or use a sequential introduction of a new treatment to determine its efficacy or effectiveness with respect to a control treatment. The reasons for choosing a particular switch design have different origins. For instance, they may be implemented for ethical or logistic reasons or for studying disease-modifying effects. Large-scale pragmatic trials with complex interventions often use stepped wedge designs (SWDs), where all participants start at the control group, and during the trial, the control treatment is switched to the new intervention at different moments. They typically use cross-sectional data and cluster randomization. On the other hand, new drugs for inhibition of cognitive decline in Alzheimer's or Parkinson's disease typically use delayed start designs (DSDs). Here, participants start in a parallel group design and at a certain moment in the trial, (part of) the control group switches to the new treatment. The studies are longitudinal in nature, and individuals are being randomized. Statistical methods for these unidirectional switch designs (USD) are quite complex and incomparable, and they have been developed by various authors under different terminologies, model specifications, and assumptions. This imposes unnecessary barriers for researchers to compare results or choose the most appropriate method for their own needs. This paper provides an overview of past and current statistical developments for the USDs (SWD and DSD). All designs are formulated in a unified framework of treatment patterns to make comparisons between switch designs easier. The focus is primarily on statistical models, methods of estimation, sample size calculation, and optimal designs for estimation of the treatment effect. Other relevant open issues are being discussed as well to provide suggestions for future research in USDs.
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Affiliation(s)
- Zhuozhao Zhan
- 1 Department of Epidemiology, University Medical Center Groningen, the Netherlands
| | - Geertruida H de Bock
- 1 Department of Epidemiology, University Medical Center Groningen, the Netherlands
| | - Edwin R van den Heuvel
- 2 Department of Mathematics and Computer Science, Technology University Eindhoven, the Netherlands
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Verberne C, Zhan Z, De Bock G, Wiggers T. 95. Intensifying colorectal cancer follow-up – Survival analysis of the randomized multicenter CEAwatch trial. Eur J Surg Oncol 2016. [DOI: 10.1016/j.ejso.2016.06.102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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Zhan Z, de Bock GH, Wiggers T, van den Heuvel E. The analysis of terminal endpoint events in stepped wedge designs. Stat Med 2016; 35:4413-4426. [PMID: 27311403 DOI: 10.1002/sim.7004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 05/03/2016] [Accepted: 05/04/2016] [Indexed: 12/25/2022]
Abstract
The stepped wedge design is a unique clinical trial design that allows for a sequential introduction of an intervention. However, the statistical analysis is unclear when this design is applied in survival data. The time-dependent introduction of the intervention in combination with terminal endpoints and interval censoring makes the analysis more complicated. In this paper, a time-on-study scale discrete survival model was constructed. Simulations were conducted primarily to study the performance of our model for different settings of the stepped wedge design. Secondary, we compared our approach to continuous Cox proportional hazard model. The results show that the discrete survival model estimates the intervention effects unbiasedly. If the length of the censoring interval is increased, the precision of the estimates is decreased. Without left truncation and late entry, the number of steps improves the precision of the estimates, whereas in combination of left truncation and late entry, the number of steps decreases the precision. Given the same number of participants and clusters, a parallel group design has higher precision than a stepped wedge design. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Zhuozhao Zhan
- Department of Epidemiology, University Medical Center Groningen, Groningen, The Netherlands
| | - Geertruida H de Bock
- Department of Epidemiology, University Medical Center Groningen, Groningen, The Netherlands
| | - Theo Wiggers
- Department of Surgery, University Medical Center Groningen, Groningen, The Netherlands
| | - Edwin van den Heuvel
- Department of Epidemiology, University Medical Center Groningen, Groningen, The Netherlands. .,Department of Mathematics and Computer Science, Eindhoven University of Technology, Eindhoven, The Netherlands.
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Zhan Z, Chen D, Yang Y, Liang L. THU0362 Adverse Pregnancy Outcomes and Associated Factors in Patients with Systemic Lupus Erythematosus. Ann Rheum Dis 2016. [DOI: 10.1136/annrheumdis-2016-eular.2931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Chen D, Zhan Z. AB0442 Spectrum and Drug Resistance of Bacteria Isolated from Hospitalized Patients with Systemic Lupus Erythematosus. Ann Rheum Dis 2016. [DOI: 10.1136/annrheumdis-2016-eular.1943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Koleva-Kolarova RG, Zhan Z, Greuter MJW, Feenstra TL, De Bock GH. Correspondence - Reply to THEBREAST-D-15-702. Breast 2016; 27:184-5. [PMID: 27056287 DOI: 10.1016/j.breast.2016.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 03/08/2016] [Indexed: 11/29/2022] Open
Affiliation(s)
- Rositsa G Koleva-Kolarova
- Department of Epidemiology, University of Groningen, University Medical Center Groningen, PO Box 30.001, 9700RB Groningen, The Netherlands; Department of Primary Care and Public Health Sciences, Division of Health and Social Care Research, King's College London, Guy's, AH 3.2, SE1 1UL London, United Kingdom.
| | - Zhuozhao Zhan
- Department of Epidemiology, University of Groningen, University Medical Center Groningen, PO Box 30.001, 9700RB Groningen, The Netherlands.
| | - Marcel J W Greuter
- Department of Radiology, University of Groningen, University Medical Center Groningen, PO Box 30.001, 9700RB Groningen, The Netherlands.
| | - Talitha L Feenstra
- Department of Epidemiology, University of Groningen, University Medical Center Groningen, PO Box 30.001, 9700RB Groningen, The Netherlands; National Institute for Public Health and the Environment (RIVM), Centre for Nutrition, Prevention and Health Services Research, PO Box 1, 3720BA Bilthoven, The Netherlands.
| | - Geertruida H De Bock
- Department of Epidemiology, University of Groningen, University Medical Center Groningen, PO Box 30.001, 9700RB Groningen, The Netherlands.
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Koleva-Kolarova RG, Zhan Z, Greuter MJW, Feenstra TL, De Bock GH. To screen or not to screen for breast cancer? How do modelling studies answer the question? ACTA ACUST UNITED AC 2015; 22:e380-2. [PMID: 26628880 DOI: 10.3747/co.22.2889] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Breast cancer screening is a topic of hot debate, and currently no general consensus has been reached on starting and ending ages and screening intervals, in part because of a lack of precise estimations of the benefit-harm ratio. Simulation models are often applied to account for the expected benefits and harms of regular screening; however, the degree to which the model outcomes are reliable is not clear. In a recent systematic review, we therefore aimed to assess the quality of published simulation models for breast cancer screening of the general population. The models were scored according to a framework for qualitative assessment. We distinguished seven original models that utilized a common model type, modelling approach, and input parameters. The models predicted the benefit of regular screening in terms of mortality reduction; and overall, their estimates compared well to estimates of mortality reduction from randomized controlled trials. However, the models did not report on the expected harms associated with regular screening. We found that current simulation models for population breast cancer screening are prone to many pitfalls; their outcomes bear a high overall risk of bias, mainly because of a lack of systematic evaluation of evidence to calibrate the input parameters and a lack of external validation. Our recommendations concerning future modelling are therefore to use systematically evaluated data for the calibration of input parameters, to perform external validation of model outcomes, and to account for both the expected benefits and the expected harms so as to provide a clear balance and cost-effectiveness estimation and to adequately inform decision-makers.
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Affiliation(s)
- R G Koleva-Kolarova
- Department of Epidemiology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Z Zhan
- Department of Epidemiology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - M J W Greuter
- Department of Radiology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - T L Feenstra
- Department of Epidemiology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands; ; rivm , Bilthoven, Netherlands
| | - G H De Bock
- Department of Epidemiology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
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Chen D, Zhan Z. AB1116 Associated Factors of Erosive Arthritis in Rheumatoid Arthritis and Other Connective Tissue Diseases: A Retrospective Study from Southern Chinese Population. Ann Rheum Dis 2015. [DOI: 10.1136/annrheumdis-2015-eular.1870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Zhan Z, Chen D, Liang L. AB0627 Tuberculosis in Systemic Lupus Erythematosus Patients: Experiences from an Endemic Area in Southern China. Ann Rheum Dis 2015. [DOI: 10.1136/annrheumdis-2015-eular.2152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Koleva-Kolarova RG, Zhan Z, Greuter MJW, Feenstra TL, De Bock GH. Simulation models in population breast cancer screening: A systematic review. Breast 2015; 24:354-63. [PMID: 25906671 DOI: 10.1016/j.breast.2015.03.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Revised: 03/17/2015] [Accepted: 03/24/2015] [Indexed: 11/15/2022] Open
Abstract
The aim of this review was to critically evaluate published simulation models for breast cancer screening of the general population and provide a direction for future modeling. A systematic literature search was performed to identify simulation models with more than one application. A framework for qualitative assessment which incorporated model type; input parameters; modeling approach, transparency of input data sources/assumptions, sensitivity analyses and risk of bias; validation, and outcomes was developed. Predicted mortality reduction (MR) and cost-effectiveness (CE) were compared to estimates from meta-analyses of randomized control trials (RCTs) and acceptability thresholds. Seven original simulation models were distinguished, all sharing common input parameters. The modeling approach was based on tumor progression (except one model) with internal and cross validation of the resulting models, but without any external validation. Differences in lead times for invasive or non-invasive tumors, and the option for cancers not to progress were not explicitly modeled. The models tended to overestimate the MR (11-24%) due to screening as compared to optimal RCTs 10% (95% CI - 2-21%) MR. Only recently, potential harms due to regular breast cancer screening were reported. Most scenarios resulted in acceptable cost-effectiveness estimates given current thresholds. The selected models have been repeatedly applied in various settings to inform decision making and the critical analysis revealed high risk of bias in their outcomes. Given the importance of the models, there is a need for externally validated models which use systematical evidence for input data to allow for more critical evaluation of breast cancer screening.
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Affiliation(s)
- Rositsa G Koleva-Kolarova
- University of Groningen, University Medical Center Groningen, Department of Epidemiology, PO Box 30.001, 9700RB Groningen, The Netherlands.
| | - Zhuozhao Zhan
- University of Groningen, University Medical Center Groningen, Department of Epidemiology, PO Box 30.001, 9700RB Groningen, The Netherlands.
| | - Marcel J W Greuter
- University of Groningen, University Medical Center Groningen, Department of Radiology, PO Box 30.001, 9700RB Groningen, The Netherlands.
| | - Talitha L Feenstra
- University of Groningen, University Medical Center Groningen, Department of Epidemiology, PO Box 30.001, 9700RB Groningen, The Netherlands; RIVM, PO Box 1, 3720BA Bilthoven, The Netherlands.
| | - Geertruida H De Bock
- University of Groningen, University Medical Center Groningen, Department of Epidemiology, PO Box 30.001, 9700RB Groningen, The Netherlands.
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Zhu M, Liu C, Wang D, Zhan Z. Detection of serum anti-melanocyte antibodies and identification of related antigens in patients with vitiligo. Genet Mol Res 2015; 14:16060-73. [DOI: 10.4238/2015.december.7.19] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Traversa FL, Zhan Z, Oriols X. Absorption and injection models for open time-dependent quantum systems. Phys Rev E Stat Nonlin Soft Matter Phys 2014; 90:023304. [PMID: 25215848 DOI: 10.1103/physreve.90.023304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Indexed: 06/03/2023]
Abstract
In the time-dependent simulation of pure states dealing with transport in open quantum systems, the initial state is located outside of the active region of interest. Using the superposition principle and the analytical knowledge of the free time evolution of such a state outside the active region, together with absorbing layers and remapping, a model for a very significant reduction of the computational burden associated with the numerical simulation of open time-dependent quantum systems is presented. The model is specially suited to study (many-particle and high-frequency effects) quantum transport, but it can also be applied to any other research field where the initial time-dependent pure state is located outside of the active region. From numerical simulations of open quantum systems described by the (effective mass) Schrödinger and (atomistic) tight-binding equations, a reduction of the computational burden of about two orders of magnitude for each spatial dimension of the domain with a negligible error is presented.
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Affiliation(s)
- F L Traversa
- Departament d'Enginyeria Electrònica, Universitat Autònoma de Barcelona, 08193-Bellaterra (Barcelona), Spain
| | - Z Zhan
- Departament d'Enginyeria Electrònica, Universitat Autònoma de Barcelona, 08193-Bellaterra (Barcelona), Spain
| | - X Oriols
- Departament d'Enginyeria Electrònica, Universitat Autònoma de Barcelona, 08193-Bellaterra (Barcelona), Spain
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Chen D, Zhan Z. SAT0029 Clinical Features and Risk Factors of Infection in Patients with Systemic Lupus Erythematosus: Experience from A Single Institute of Southern China. Ann Rheum Dis 2014. [DOI: 10.1136/annrheumdis-2014-eular.3052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Zhan Z, Chen D, Yuan S, Liang L. SAT0034 Assessment of Ovarian Reserve with Anti-MÜLlerian Hormone in Female Patients with Systemic Lupus Erythematosus. Ann Rheum Dis 2014. [DOI: 10.1136/annrheumdis-2014-eular.4316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Liao X, Luo Y, Zhan Z, Du J, Hu Z, Wang J, Guo J, Hu Z, Yan X, Pan Q, Xia K, Tang B, Shen L. SPG35 contributes to the second common subtype of AR-HSP in China: frequency analysis and functional characterization of FA2H gene mutations. Clin Genet 2014; 87:85-9. [PMID: 24359114 DOI: 10.1111/cge.12336] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 12/13/2013] [Accepted: 12/18/2013] [Indexed: 11/29/2022]
Abstract
Hereditary spastic paraplegias (HSPs) encompass a clinically and genetically heterogeneous group of neurodegenerative disorders. Recently, mutations in fatty acid 2-hydroxylase gene (FA2H) have been identified responsible for HSPs type 35 (SPG35). This study aims to define the contribution of FA2H to Chinese autosomal recessive HSP (AR-HSP) patients and provide insights into the enzymatic functions of the novel mutations. Direct sequencing of FA2H was conducted in 31 AR-HSP families and 55 sporadic cases without SPG11, SPG15, SPG5 and SPG7 gene mutations. Enzymatic activity of the mutated proteins was further examined. Three novel mutations were found in two Chinese families, including two compound heterozygous mutations (c.388C>T/p.L130F and c.506+6C>G) and one homozygous mutation (c.230T>G/p.L77R). The c.506+6C>G splice-site mutation led to the deletion of exon 3. Measurement of enzymatic functions revealed a significant reduction in the enzymatic activity of FA2H associated with p.L130F and p.L77R. Overall, our data widens the spectrum of the mutations on FA2H, and functional analyses indicate that these mutations severely impair the enzymatic activity of FA2H. Furthermore, frequency analysis shows that SPG35 is the second most common subtype of AR-HSP in China.
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Affiliation(s)
- X Liao
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
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Lian F, Wang Y, Xu H, Chen D, Zhan Z, Liang L, Qiu Q, Ye Y, Yang X. AB0634 Chinese experience with tripterygium wilfordii multiglycoside as long-term maintenance therapy in lupus nephritis. Ann Rheum Dis 2014. [DOI: 10.1136/annrheumdis-2012-eular.634] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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