Radiomics nomogram based on MRI water imaging identifying symptomatic nerves of patients with primary trigeminal neuralgia: A preliminary study

The study proposes a combined nomogram based on radiomics features from magnetic resonance neurohydrography and clinical features to identify symptomatic nerves in patients with primary trigeminal neuralgia. We retrospectively analyzed 140 patients with clinically confirmed trigeminal neuralgia. Out of these, 24 patients constituted the external validation set, while the remaining 116 patients contributed a total of 231 nerves, comprising 118 symptomatic nerves, and 113 normal nerves. Radiomics features were extracted from the MRI water imaging (t2-mix3d-tra-spair). Radiomics feature selection was performed using L1 regularization-based regression, while clinical feature selection utilized univariate analysis and multivariate logistic regression. Subsequently, radiomics, clinical, and combined models were developed by using multivariate logistic regression, and a nomogram of the combined model was drawn. The performance of nomogram in discriminating symptomatic nerves was assessed through the area under the curve (AUC) of receiver operating characteristics, accuracy, and calibration curves. Clinical applications of the nomogram were further evaluated using decision curve analysis. Five clinical factors and 13 radiomics signatures were ultimately selected to establish predictive models. The AUCs in the training and validation cohorts were 0.77 (0.70-0.84) and 0.82 (0.72-0.92) with the radiomics model, 0.69 (0.61-0.77) and 0.66 (0.53-0.79) with the clinical model, 0.80 (0.74-0.87), and 0.85 (0.76-0.94) with the combined model, respectively. In the external validation set, the AUCs for the clinical, radiomics, and combined models were 0.70 (0.60-0.79), 0.78 (0.65-0.91), and 0.81 (0.70-0.93), respectively. The calibration curve demonstrated that the nomogram exhibited good predictive ability. Moreover, The decision curve analysis curve indicated shows that the combined model holds high clinical application value. The integrated model, combines radiomics features from magnetic resonance neurohydrography with clinical factors, proves to be effective in identify symptomatic nerves in trigeminal neuralgia. The diagnostic efficacy of the combined model was notably superior to that of the model constructed solely from conventional clinical features.

Performance of Tools and Measures to Predict Fluid Responsiveness in Pediatric Shock and Critical Illness: A Systematic Review and Meta-Analysis

OBJECTIVES

In this systematic review and meta-analysis we asked: Do predictors of fluid responsiveness in children perform comparably: 1) in the PICU as in non-PICU settings? 2) in shock states compared with nonshock states? Additionally, 3) is there an association between preload responsiveness and clinical response?

DATA SOURCES

Ovid Medline, PubMed, and Embase databases were searched from inception through May 2022.

STUDY SELECTION

Included studies reported physiological response to IV fluid administration in humans less than 18 years. Only studies reporting an area under the receiver operating characteristic curve (AUROC) were included for descriptive analysis. Only studies for which a se could be estimated were included for meta-analysis.

DATA EXTRACTION

Title, abstract, full text screening, and extraction were completed by two authors (S.B.W., J.M.W.). Variables extracted included predictors ("tools") and outcome measures ("reference tests") of fluid responsiveness, demographic, and clinical variables.

DATA SYNTHESIS

We identified 62 articles containing 204 AUROCs for 55 tools, primarily describing mechanically ventilated children in an operating room or PICU. Meta-analysis across all tools showed poor predictive performance (AUROC, 0.66; 95% CI, 0.63-0.69), although individual performance varied greatly (range, 0.49-0.87). After controlling for PICU setting and shock state, PICU setting was associated with decreased predictive performance (coefficient, -0.56; p = 0.0007), while shock state was associated with increased performance (0.54; p = 0.0006). Effect of PICU setting and shock state on each tool was not statistically significant but analysis was limited by sample size. The association between preload responsiveness and clinical response was rarely studied but results did not suggest an association. Ultrasound measurements were prone to inherent test review and incorporation biases.

CONCLUSIONS

We suggest three opportunities for further research in fluid responsiveness in children: 1) assessing predictive performance of tools during resuscitation in shock states; 2) separating predictive tool from reference test when using ultrasound techniques; and 3) targeting decreasing time in a shock state, rather than just increase in preload.

The clinical implications of choroidal thickness combined with tear VEGFA in coronary artery disease

OBJECTIVE

The purpose of this study was to evaluate the effect of choroidal thickness and tear vascular endothelial growth factor A (VEGFA) as biomarkers of coronary artery disease (CAD).

METHODS

This study was a retrospective observational case-control trial. A total of 637 patients who underwent coronary angiography to assess their coronary artery status were included. The patients were divided into two groups: 200 people in the No CAD group and 437 people in the CAD group. We evaluated the choroidal thickness of the right foveal membrane in all patients through optical coherence tomography angiography examination. We also collected tear samples from patients to measure VEGFA. The ROC curve and its area under the curve (AUC) were used for analysis.

RESULTS

The central foveal choroid in the No CAD group was significantly thicker than that in the CAD group (289.09 μm ± 38.41; 229.03 μm ± 33.44, P  < 0.01). The tear VEGFA in the CAD group was higher than that in the No CAD group (706.15 ng/mL ± 147.42; 419.66 ng/mL ± 105.85, P  < 0.01). Spearman analysis showed that the correlation between choroidal thickness and Gensini score was -0.7387 ( P  < 0.01). The correlation between tear VEGFA level and Gensini score was 0.8636 ( P  < 0.01). Taking choroidal thickness and tear VEGFA as independent variables, we obtained AUC = 0.9647 (95% CI 0.9506-0.9789, P  < 0.01) through binary logic regression and ROC curve analysis.

CONCLUSION

The combination of choroidal thickness and tear VEGFA in patients can serve as a clinical marker of CAD and its severity.

The relationship between nonsystematic delay discounting and low-quality survey responses in a sample of smokers: ROC curve analysis

Delay discounting (DD), the decrease of the subjective value of a reward as the delay to its receipt increases, is a crucial aspect of decision-making processes. As evidence continues to mount, additional attention needs to be given to nonsystematic DD, a response pattern that has been reported in the literature but rarely investigated. We noticed in our recent online research an increase in the proportion of nonsystematic DD responses across samples, consistent with the so-called Amazon Mechanical Turk (MTurk) data quality crisis. The significant proportion of nonsystematic responses created an opportunity to investigate its association with data quality in the present study. In a sample of smokers recruited from MTurk (n = 210), three independent quality check indexes evaluated participants' response quality. The degree of nonsystematic DD was quantified by the algorithms developed by Johnson and Bickel (2008). The area under the receiver operating characteristic curve (AUC) predicting response quality by nonsystematic DD was obtained. The observed AUC values were at the extreme of the null distributions (ps < .001) in a permutation test. Furthermore, the nonsystematic DD cutoffs provided in Johnson and Bickel (2008) showed good sensitivity (0.77-0.93), albeit low-moderate specificity (0.42-0.74), in detecting low-quality responses. The findings showed that nonsystematic DD was associated with low-quality responses, although other factors contributing to the nonsystematic responses remain to be identified. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Comparison of Race-Based and Non-Race-Based Glomerular Filtration Rate Equations for the Assessment of Renal Functional Risk Before Nephrectomy

OBJECTIVE

To compare the performance of race-based and race-neutral estimated glomerular filtration rate (eGFR) calculators in patients undergoing kidney surgery.

METHODS

Analysis of institutional kidneys surgeries from 2006-2021 was conducted. Demographics, serum creatinine (SCr), protein dipstick, and creatinine clearance (CrCl) were assessed within 1 week prior to surgery. SCr was used to calculate eGFR using 3 models: Modification of Diet in Renal Disease (MDRD), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI 2009), and CKD-EPI 2021. Patients were classified based on Kidney Disease: Improving Global Outcomes (KDIGO) criteria for CKD staging and prognosis, with urine CrCl treated as benchmark for analysis. Receiver operating characteristic (ROC) analysis evaluated accuracy of eGFR calculators' binary discrimination of eGFR less than 60 mL/min. CKD stage agreement between eGFR and urine CrCl was assessed.

RESULTS

A total of 554 kidney surgeries in 336 patients had necessary laboratory data for analysis. The cohort was 62% male, with a median age of 47. Within this cohort, 8.1% (n=45) were Black, and 80% (n=441) were White. glomerular filtration rate (GFR) from 24-hour urine CrCl normalized by BSA did not vary significantly from eGFR by SCr based calculators. The proportion of patients with eGFR <60 significantly differed when using Modification of Diet in Renal Disease, CKD-EPI 2009, and CKD-EPI 2021 equations when compared to CrCl (P<.001). Still, they performed equivalently in the staging of CKD, as well as in predicting GFR of less than 60, and classifying CKD prognosis of "moderately increased or higher".

CONCLUSION

A race-neutral eGFR calculator can perform equivalently to established eGFR calculators, with the added benefit of mitigating biases that account for racial disparities in nephrectomy decision making.

The Clinical Implementation of NEWS, SOFA, and CALL Scores in Predicting the In-Hospital Outcome of Severe or Critical COVID-19 Patients

OBJECTIVE

To date, there is no specific validated coronavirus disease 2019 score to assess the disease severity. This study aimed to evaluate the performance of the National Early Warning Score, Sequential Organ Failure Assessment, and Comorbidity-Age-Lymphocyte count-Lactate dehydrogenase scores in predicting the in-hospital outcome of critical or severe coronavirus disease 2019 patients.

MATERIALS AND METHODS

Single-centered analytical study was carried out in the coronavirus disease 2019 high dependency unit from April to August 2020. National Early Warning Score, Sequential Organ Failure Assessment, and Comorbidity-Age-Lymphocyte count-Lactate dehydrogenase scores were calculated for each critical to severely ill coronavirus disease 2019 patient. The diagnostic accuracy of these 3 scores in determining the in-hospital outcome of coronavirus disease 2019 patients was assessed by area under the receiver operating characteristic curve. The cut-off value of each score along with sensitivity, specificity, and positive and negative likelihood ratio were calculated by Youden index. Predictors of outcome in coronavirus disease 2019 patients were analyzed by Cox-regression analysis.

RESULTS

The area under the curve was highest for the Comorbidity-Age-Lymphocyte count-Lactate dehydrogenase score (area under the curve=0.85) while the Sequential Organ Failure Assessment score had an area under the curve of 0.72. The cut-off values for National Early Warning Score score was 8 (sensitivity=72.34%, specificity=76.10%), Sequential Organ Failure Assessment score was 3 (sensitivity=68.97%, specificity=67.42%), and Comorbidity-Age-Lymphocyte count-Lactate dehydrogenase score was 8 (sensitivity=88.89%, specificity=66.67%). The pairwise comparison showed that the difference between the area under the curve of these 3 scores was statistically insignificant (P > .05). The rate of mortality and invasive ventilation was significantly high in groups with high National Early Warning Score, Sequential Organ Failure Assessment, and Comorbidity-Age-Lymphocyte count-Lactate dehydrogenase scores (P > .0001). These 3 scores, age, low platelets, and high troponin-T levels were found to be statistically significant predictors of outcome Conclusion:Comorbidity-Age-Lymphocyte count-Lactate dehydrogenase score had a good area under the curve, the highest sensitivity of its cut-off value, required only 4 parameters, and is easy to calculate so it may be a better tool among the 3 scores in outcome prediction for coronavirus disease 2019 patients.

The lowest effective plasma concentration of atomoxetine in pediatric patients with attention deficit/hyperactivity disorder: A non-randomized prospective interventional study

BACKGROUND

Atomoxetine (ATX) is used as a first-line, non-stimulant treatment for attention-deficit/hyperactivity disorder (ADHD), although no studies have systematically examined the relationship between plasma concentration and clinical efficacy. We conducted this non-randomized prospective interventional study to examine the relationship between plasma concentration of ATX and clinical efficacy.

METHODS

Forty-three ADHD pediatric patients received ATX, and the steady-state through plasma concentration of the last daily dose that was maintained for at least 4 weeks were determined by high-performance liquid chromatography.

RESULTS

The receiver operating characteristic curve suggested that when plasma concentration exceeded 64.60 ng/mL, scores on the ADHD-Rating Scale improved by 50% or more (P = .14). Although 6 of the 8 final responders were unresponsive at the initial dose (.72 ± .04 mg/kg [mean ± standard deviation]), they responded after increasing the ATX dose to the final dose (1.52 ± .31 mg/kg). Excluding 7 outlier participants, the concentration was 83.3 ± 32.3 ng/mL in 7 responders and was significantly higher than 29.5 ± 23.9 ng/mL (P < .01) for the 29 non-responders.

CONCLUSIONS

These results suggest that a minimum effective plasma concentration of ATX is required to achieve sufficient clinical efficacy. We hypothesized a mechanism that results in the realization of a clinical effect when the plasma concentration exceeds a certain threshold in the potential response group, whereas will not improve even if the plasma concentration is increased in the unqualified non-responder group.

Clinical Scoring Systems in Predicting the Outcomes of Small Bowel Bleeding

BACKGROUND

The aim was to assess the clinical Glasgow-Blatchford score (GBS), Rockall score (CRS), and AIMS65 score in predicting outcomes (rebleeding, need for intervention, and length of stay) among patients with small bowel hemorrhage.

METHODS

We conducted a retrospective study of patients with small bowel bleeding (SBB). Rebleeding, need for intervention, and length of stay was investigated by 3 scoring systems. The area under the receiver operator characteristic curve was used to analyze the performance of 3 scoring systems.

RESULTS

Among 162 included patients, the scores of rebleeding, intervention, and length of stay ≥10 days groups were higher than no rebleeding, non-intervention, and length of stay <10 days groups, respectively (P < .05). The CRS, GBS, and AIMS65 scoring systems demonstrated statistically significant difference in predicting rebleeding (AUROC 0.693 vs. 0.790 vs. 0.740; all P < .01), intervention (AUROC: 0.726 vs. 0.825 vs. 0.773; all P < .01) and length of stay (AUROC 0.651 vs. 0.631 vs. 0.635; all P < .05). Higher cut-off scores achieved better sensitivity/specificity [rebleeding (CRS > 2, GBS > 7, AIMS65 > 0); need for intervention (CRS > 2, GBS > 7, AIMS65 > 0); length of stay (CRS > 0, GBS > 7, AIMS65 > 1)] in the risk stratification.

CONCLUSIONS

The GBS system is reliable to be recommended for routine use in predicting rebleeding and the need for intervention for early decision making in patients with SBB. The 3 scoring systems are poorly useful in predicting length of stay.

Tailoring Body Mass Index for Prediction of Obesity in Young Adults: A Multi-Centric Study on MBBS Students of Southeast India

INTRODUCTION

Body mass index (BMI) has been used for a long period as a surrogative measure for obesity. But BMI does not differentiate between fat and nonfat tissue (blood, bone, and muscle) due to which it is not considered accurate anymore. But since BMI is easier to estimate and used widely for assessment of obesity, it is better if it is re-standardized according to the body fat percentage (BFP) of a specific population, community, and their ethnicity.

OBJECTIVE

To estimate and propose the BMI cut-off values in young Indian population especially MBBS students taking BFP as a standard.

DESIGN

This is a cross-sectional study. Anthropometric data (age, gender, height, weight, waist circumference, and hip circumference) were collected from the participants after taking consent. BMI was calculated using Quetelet's Rule. BFP was estimated using Omron Body fat Monitor (HBF 385). It measures the BFP by the bioelectrical impedance (BI) method. Data were analyzed with appropriate statistical tests and receiver operating curve (ROC) curves were drawn to find the cut-off values of BMI to determine obesity.

SETTING

The present study is a multi-centric study conducted in four medical colleges (two in each state; Odisha and Andhra Pradesh, India).

PARTICIPANTS

Apparently healthy MBBS students aged 18-24 years were included in this study. Students having any chronic or acute illnesses were excluded from the study. Out of 904 students contacted from four medical colleges, 863 (430 males and 433 females) consented and participated.

RESULTS

Some 863 MBBS students have participated in this study. After adjusting for age, BMI was found to be higher in males. BMI was found to be 29.33 for males and in females it was 29.06. BFP was higher in females (34.23) as compared to males (20.77). Waist hip ratio was found to be higher in females (0.92) than in males (0.84). Whereas, fat free mass (FFM) and fat free mass index (FFMI) are higher in males, i.e., 56.24 and 18.48 respectively. Most appropriate cut-off value for obesity on ROC curve was found to be 22.09 (sensitivity 84.5%, specificity 83.46%) in males and that of females was 23.73 (sensitivity 85.26, specificity 81.23). Whereas, the conventional cut-off of 25 for males had sensitivity of only 46% and that of females was 70.5%. For total population BMI cut-off value was found to be 22.2 with 81% sensitivity and 74% specificity.  Conclusion: We propose the cut-off value for overweight/obesity in males to be 22.09 kg/m² and for females to be 23.73 kg/m² in young adult Indian population. These values were found to have more sensitivity and specificity than current BMI cut-off value.

Impaired immune and coagulation systems may be early risk factors for COVID-19 patients: A retrospective study of 118 inpatients from Wuhan, China

The coronavirus disease 2019 (COVID-19) outbreak has become a global health threat and will likely be one of the greatest global challenges in the near future. The battle between clinicians and the COVID-19 outbreak may be a "protracted war."The objective of this study was to investigate the risk factors for in-hospital mortality in patients with COVID-19, so as to provide a reference for the early diagnosis and treatment.This study retrospectively enrolled 118 patients diagnosed with COVID-19, who were admitted to Eastern District of Renmin Hospital of Wuhan University from February 04, 2020 to March 04, 2020. The demographics and laboratory data were collected and compared between survivors and nonsurvivors. The risk factors of in-hospital mortality were explored by univariable and multivariable logistic regression to construct a clinical prediction model, the prediction efficiency of which was verified by receiver-operating characteristic (ROC) curve.A total of 118 patients (49 males and 69 females) were included in this study; the results revealed that the following factors associated with in-hospital mortality: older age (odds ratio [OR] 1.175, 95% confidence interval [CI] 1.073-1.287, P = .001), neutrophil count greater than 6.3 × 10 cells/L (OR 7.174, (95% CI 2.295-22.432, P = .001), lymphocytopenia (OR 0.069, 95% CI 0.007-0.722, P = .026), prothrombin time >13 seconds (OR 11.869, 95% CI 1.433-98.278, P = .022), D-dimer >1 mg/L (OR 22.811, 95% CI 2.224-233.910, P = .008) and procalcitonin (PCT) >0.1 ng/mL (OR 23.022, 95% CI 3.108-170.532, P = .002). The area under the ROC curve (AUC) of the above indicators for predicting in-hospital mortality were 0.808 (95% CI 0.715-0.901), 0.809 (95% CI 0.710-0.907), 0.811 (95% CI 0.724-0.898), 0.745 (95% CI 0.643-0.847), 0.872 (95% CI 0.804-0.940), 0.881 (95% CI 0.809-0.953), respectively. The AUC of combined diagnosis of these aforementioned factors were 0.992 (95% CI 0.981-1.000).In conclusion, older age, increased neutrophil count, prothrombin time, D-dimer, PCT, and decreased lymphocyte count at admission were risk factors associated with in-hospital mortality of COVID-19. The prediction model combined of these factors could improve the early identification of mortality risk in COVID-19 patients.

Serum ammonia levels on admission for predicting sepsis patient mortality at D28 in the emergency department: A 2-center retrospective study

We assessed the predictive value of serum ammonia level on admission for the 28-day mortality of patients with sepsis.We retrospectively included septic patients admitted to the emergency department of West China Hospital, Sichuan University and The Fourth People's Hospital of Zigong city from June 2017 to May 2018. Patients were divided into 2 groups according to 28-day survival. Comparisons of serum ammonia level and sequential organ failure assessment (SOFA) score were made between 2 groups. Multivariate logistic regression models were employed to determine independent risk factors affecting 28-day mortality rate, and receiver operating characteristic (ROC) curve was also used to evaluate the efficacy of risk factors.Total of 316 patients were included into the study, 221 survived to 28 days and 95 were died before 28 days. The 28-day mortality rate was 30.06%. Multivariate logistic regression analyses revealed that the ammonia level, C reactive protein, SOFA score, and the leukocyte were independent risk factors for the 28-day mortality rate. In predicting the 28-day mortality rate, the SOFA score presented an area under the ROC curve (AUC) of 0.815, and the ammonia levels presented the AUC of 0.813.The ammonia level, C reactive protein, SOFA score, and the leukocyte are independent risk factors for 28-day mortality rate in septic patients. Moreover, the serum ammonia and SOFA score have similar predictive values. The serum ammonia level is also a suitable early indicator for prognostic evaluation of patients with sepsis as well.

Amount of physical activity necessary for a normal level of high-sensitivity C-reactive protein in ELSA-Brasil: a cross-sectional study

BACKGROUND

Studies have shown that physical activity levels can be inversely associated with high-sensitivity C-reactive protein (hs-CRP) levels. However, the amount of physical activity required to maintain normal hs-CRP levels is still a matter for speculation.

OBJECTIVE

To identify the amount of physical activity necessary to discriminate the hs-CRP levels in adults.

DESIGN AND SETTING

Cross-sectional study at six teaching and research institutions.

METHODS

The study sample comprised 10,231 adults aged 35 to 74 years who were participants in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). Receiver operating characteristic (ROC) curves were constructed to compare the amount of physical activity in two domains (leisure time and commuting) with hs-CRP levels. The sensitivity and specificity were calculated to identify the best cutoff for physical activity level that would be needed to maintain normal levels of hs-CRP (< 3 mg/l).

RESULTS

The area under the ROC curve was only statistically significant for discriminating normal levels of hs-CRP according to the amount of physical activity when the two study domains were added together. The accumulated physical activity level of 200 minutes/week was the best cutoff for discriminating normal levels of hs-CRP in adults of both sex.

CONCLUSIONS

Physical activity in the leisure-time and commuting domains together, of duration 200 minutes/week, was associated with normal hs-CRP values.

The use of APACHE II, SOFA, SAPS 3, C-reactive protein/albumin ratio, and lactate to predict mortality of surgical critically ill patients: A retrospective cohort study

Several prognostic indices have been employed to predict the outcome of surgical critically ill patients. Among them, acute physiology and chronic health evaluation (APACHE) II, sequential organ failure assessment (SOFA) and simplified acute physiology score (SAPS 3) are widely used. It seems that biological markers such as C-reactive protein (CRP), albumin, and blood lactate levels correlate with the degree of inflammation during the immediate postoperative phase and could be used as independent predictors. The objective of this study is to compare the different predictive values of prognostic indices and biological markers in the outcome of 847 surgical patients admitted to the intensive care unit (ICU) in the postoperative phase.The patients were divided into survivors (n = 765, 57.4% males, age 61, interquartile range 51-71) and nonsurvivors (n = 82, 57.3% males, age 70, interquartile range 58-79). APACHE II, APACHE II death probability (DP), SOFA, SAPS 3, SAPS 3 DP, CRP, albumin, and lactate were recorded on ICU admission (first 24 hours). The area under the ROC curve (AUROC) and 95% confidence interval (95% CI) were used to measure the index accuracy to predict mortality.The AUROC and 95% CI for APACHE II, APACHE II DP, SOFA, SAPS 3, SAPS 3 DP, CRP/albumin ratio, CRP, albumin, and lactate were 0.850 (0.824-0.873), 0.855 (0.829-0.878), 0.791 (0.762-0.818), 0.840 (0.813-0.864), 0.840 (0.813-0.864), 0.731 (0.700-0.761), 0.708 (0.676-0.739), 0.697 (0.665-0.728), and 0.601 (0.567-0.634), respectively. The ICU and overall in-hospital mortality were 6.6 and 9.7%, respectively. The APACHE II, APACHE II DP, SAPS 3, SAPS 3 DP, and SOFA scores showed a better performance than CRP/albumin ratio, CRP, albumin, or lactate to predict in-hospital mortality of surgical critically ill patients.Even though all indices were able to discriminate septic from nonseptic patients, only APACHE II, APACHE II DP, SOFA and to a lesser extent SAPS 3, SAPS 3 DP, and blood lactate levels could predict in the first 24-hour ICU admission surgical patients who have survived sepsis.

Significance of contrast-enhanced ultrasonography in differential diagnosis of thyroid nodules

The present study was aimed to compare the application values between 2-dimensional color Doppler ultrasonography (2DUS) and contrast-enhanced ultrasonography (CEUS) in the differential diagnosis of thyroid malignant nodules.A total of 124 patients suspectedly diagnosed with malignant thyroid nodules under conventional gray-scale ultrasonography were recruited in this study. All enrolled patients were examined by both 2DUS and CEUS.A total of 153 nodules (94.44%) and 45 cases (90.00%) with malignant nodules were detected by the CEUS. No significant differences were noted in nodule detection rates between 2DUS and CEUS (χ = 1.170, P = .279; χ = 0.796, P = .372). The aspect ratio, microcalcification, internal echo, borderline, Vmax, resistance index, and total scores of malignant nodules were higher than those of benign nodules (all P < .05) when diagnosed by 2DUS. The peripheral/internal enhancement time, peak intensity, local enhancement, ring enhancement, and total scores of malignant nodules were significantly higher compared with those of benign nodules (all P < .05) by CEUS. Total score of malignant nodules diagnosed by 2DUS was approximately 3.5 and 2.3 points for CEUS. The diagnostic accuracy of 2DUS as observed by area under the curve was 0.821 with the cut-off value of 3.9, the sensitivity was 82.5%, and the specificity was 85.6%. The diagnostic accuracy of CEUS was 0.862 with the cut-off value of 2.8, the sensitivity was 86.7%, and the specificity was 91.3%.Both 2DUS and CEUS are worthy of application values in the differential diagnosis from benign to malignant thyroid nodules.

Time Spent in Sedentary Behaviour as Discriminant Criterion for Frailty in Older Adults

This paper aims to analyse whether time spent in sedentary behaviour was a discriminant criterion for frailty in older adults. This was a cross-sectional study conducted in a sample of 457 elderly individuals aged ≥60 years. Frailty was defined as the presence of three or more of the following criteria: Unintentional weight loss, low walking speed at a 4.57 m course, reduced manual grip strength, exhaustion and insufficient physical activity level. Participants were classified into two groups: Non-frail or frail. Exposure to sedentary behaviour was assessed by the time spent sitting during a typical week, according to the adapted version of the International Physical Activity Questionnaire. Descriptive (mean, frequency) and inferential statistics (Poisson regression, Pearson’s Chi-square, Receiver Operating Characteristic Curve) were used to analyse the data, comparing them to the time-related areas exposed to sedentary behaviour by gender and the presence of fragility. The prevalence of frailty was 22.1% (n = 101). The most accurate cut-off points of sitting time for predicting frailty were >495 min/day (men) or >536 min/day (women). Time spent in sedentary behaviour can be used to indicate fragility in the elderly of both sexes.

Is the admission test for a course in medicine a good predictor of academic performance? A case-control experience at the school of medicine of Turin

OBJECTIVES

The usefulness of university admission tests to medical schools has been discussed in recent years. In the academic year 2014-15 in Italy, several students who failed the admission test appealed to the regional administrative court ('Tribunale Amministrativo Regionale'-TAR) requesting to be included, despite their test results, and all were admitted to their respective courses. The existence of this population of students generated a control group, in order to evaluate the predictive capacity of the admission test. The aim of the present work is to discuss the ability of university admission tests to predict subsequent academic success.

SETTING AND PARTICIPANTS

The study involved 683 students who enrolled onto the first year of the degree course in medicine in the academic year 2014-15 at the University of Turin (Molinette and San Luigi Gonzaga colleges). The students were separated into two categories: those who passed the admission test (n1=531) and those who did not pass the admission test but won their appeal in the TAR (n2=152).

OUTCOMES

The validity of the admission test was analysed using specificity, sensitivity, positive and negative likelihood ratios (LH+, LH-), receiver operating characteristic (ROC) curves, area under the ROC curve (AUC), and relative (95% CI).

RESULTS

The results showed that the admission test appeared to be a good tool for predicting the academic performances in the first year of the course (AUC=0.70, 95% CI 0.64 to 0.76). Moreover, some subject areas seemed to have a greater discriminating capacity than others. In general, students who obtained a high score in scientific questions were more likely to obtain the required standards during the first year (LH+ 1.22, 95% CI 1.14 to 1.25).

CONCLUSIONS

Based on a consistent statistical approach, our study seems to confirm the ability of the admission test to predict academic success in the first year at the school of medicine of Turin.

micro-RNA screening and prediction model construction for diagnosis of salt-sensitive essential hypertension

Commonly used tests for diagnosis of salt-sensitive hypertension (SSH) are complex and time-consuming, so new methods are required. Many studies have demonstrated roles for miRNAs in hypertension; however, the diagnostic value of miRNAs has yet to be determined for human SSH. In this study, we examined miRNA expression profiles by initial high-throughput miRNA sequencing of samples from patients with salt-sensitive and salt-resistant hypertension (SSH and SRH, respectively; n = 6, both groups), followed by validation by quantitative real-time polymerase chain reaction (qRT-PCR) in a larger cohort (n = 91). We also evaluated differences in baseline characteristics (e.g., age, sex, body mass index, consumption of specific foods) between the SSH and SRH groups. Of 36 miRNAs identified as differentially expressed between SSH and SRH groups by RNA-Seq, 8 were analyzed by qRT-PCR. There were significant differences in the expression levels of hsa-miR-361-5p and hsa-miR-362-5p between the 2 groups (P = .023 and.049, respectively). In addition, there were significant differences in sauce and poultry consumption between the 2 groups (P = .004 and.001, respectively). The areas under the curve (AUC) determined by receptor operating characteristic (ROC) analysis for hsa-miR-361-5p and all 8 miRNAs were 0.793 (95% CI, 0.698-0.888; sensitivity = 73.9%, specificity = 74.4%; P < .001) and 0.836 (95% CI, 0.749-0.922; sensitivity = 80.4%, specificity = 81.4%; P < .001), respectively, when sauce and poultry consumption were included in the models. Assay feasibility and economic considerations make hsa-miR-361-5p combined with the dietary factors the preferred markers for diagnosis of SSH.

Leptin as a predictor of metabolic syndrome in prepubertal children

OBJECTIVE

Leptin has been suggested as a potential biomarker of cardiovascular risk. This paper aims to ascertain, based on a sample of prepubertal children, which serum leptin value best suited to identify metabolic syndrome (MS).

SUBJECTS AND METHODS

This observational, cross-sectional study recruited children from the outpatient pediatrics clinic, with the purpose of validating serum leptin level cutoffs to identify MS. All obese and overweight children who met eligibility criteria were included in the study, as was a sample of normal-weight children. The sample underwent clinical assessment and blood fasting glucose, lipid profile, insulin, and leptin were measured. Sensitivity and specificity were estimated for each leptin measurement, using MS as the outcome. These values were used to construct a receiver operating characteristic (ROC) curve. The association between MS and leptin was assessed using logistic models to predict MS.

RESULTS

A total of 65 normal weight, 46 overweight, and 164 obese children were analyzed (160 boys, 115 girls; age: 93.7 ± 17.8 months). The most appropriate leptin cutoff was 13.4 ng/mL (sensitivity 67.6%; specificity 68.9%; accuracy 72.1%). The logistic model indicated that leptin levels above 13.4 ng/dL were significantly associated with MS and that, for every 1 ng/dL increase in leptin levels, the odds of MS increase by 3% (p = 0.002; OR 1.03; 95% CI 1.01-1.05).

CONCLUSIONS

Leptin may be a useful biomarker of cardiovascular risk in prepubertal children, with an optimal cutoff of 13.4 ng/mL. Identification of potential new risk markers for cardiovascular disease in children could contribute to the development of preventive strategies.

Screening for physical inactivity among adults: the value of distance walked in the six-minute walk test. A cross-sectional diagnostic study

CONTEXT AND OBJECTIVES

Accelerometry provides objective measurement of physical activity levels, but is unfeasible in clinical practice. Thus, we aimed to identify physical fitness tests capable of predicting physical inactivity among adults.

DESIGN AND SETTING

Diagnostic test study developed at a university laboratory and a diagnostic clinic.

METHODS

188 asymptomatic subjects underwent assessment of physical activity levels through accelerometry, ergospirometry on treadmill, body composition from bioelectrical impedance, isokinetic muscle function, postural balance on a force platform and six-minute walk test. We conducted descriptive analysis and multiple logistic regression including age, sex, oxygen uptake, body fat, center of pressure, quadriceps peak torque, distance covered in six-minute walk test and steps/day in the model, as predictors of physical inactivity. We also determined sensitivity (S), specificity (Sp) and area under the curve of the main predictors by means of receiver operating characteristic curves.

RESULTS

The prevalence of physical inactivity was 14%. The mean number of steps/day (≤ 5357) was the best predictor of physical inactivity (S = 99%; Sp = 82%). The best physical fitness test was a distance in the six-minute walk test and ≤ 96% of predicted values (S = 70%; Sp = 80%). Body fat > 25% was also significant (S = 83%; Sp = 51%). After logistic regression, steps/day and distance in the six-minute walk test remained predictors of physical inactivity.

CONCLUSION

The six-minute walk test should be included in epidemiological studies as a simple and cheap tool for screening for physical inactivity.

Disadvantages of using the area under the receiver operating characteristic curve to assess imaging tests: a discussion and proposal for an alternative approach

OBJECTIVES

The objectives are to describe the disadvantages of the area under the receiver operating characteristic curve (ROC AUC) to measure diagnostic test performance and to propose an alternative based on net benefit.

METHODS

We use a narrative review supplemented by data from a study of computer-assisted detection for CT colonography.

RESULTS

We identified problems with ROC AUC. Confidence scoring by readers was highly non-normal, and score distribution was bimodal. Consequently, ROC curves were highly extrapolated with AUC mostly dependent on areas without patient data. AUC depended on the method used for curve fitting. ROC AUC does not account for prevalence or different misclassification costs arising from false-negative and false-positive diagnoses. Change in ROC AUC has little direct clinical meaning for clinicians. An alternative analysis based on net benefit is proposed, based on the change in sensitivity and specificity at clinically relevant thresholds. Net benefit incorporates estimates of prevalence and misclassification costs, and it is clinically interpretable since it reflects changes in correct and incorrect diagnoses when a new diagnostic test is introduced.

CONCLUSIONS

ROC AUC is most useful in the early stages of test assessment whereas methods based on net benefit are more useful to assess radiological tests where the clinical context is known. Net benefit is more useful for assessing clinical impact.

KEY POINTS

• The area under the receiver operating characteristic curve (ROC AUC) measures diagnostic accuracy. • Confidence scores used to build ROC curves may be difficult to assign. • False-positive and false-negative diagnoses have different misclassification costs. • Excessive ROC curve extrapolation is undesirable. • Net benefit methods may provide more meaningful and clinically interpretable results than ROC AUC.

Stratification of complexity in congenital heart surgery: comparative study of the Risk Adjustment for Congenital Heart Surgery (RACHS-1) method, Aristotle basic score and Society of Thoracic Surgeons-European Association for Cardio- Thoracic Surgery (STS-EACTS) mortality score

OBJECTIVE

To determine whether stratification of complexity models in congenital heart surgery (RACHS-1, Aristotle basic score and STS-EACTS mortality score) fit to our center and determine the best method of discriminating hospital mortality.

METHODS

Surgical procedures in congenital heart diseases in patients under 18 years of age were allocated to the categories proposed by the stratification of complexity methods currently available. The outcome hospital mortality was calculated for each category from the three models. Statistical analysis was performed to verify whether the categories presented different mortalities. The discriminatory ability of the models was determined by calculating the area under the ROC curve and a comparison between the curves of the three models was performed.

RESULTS

360 patients were allocated according to the three methods. There was a statistically significant difference between the mortality categories: RACHS-1 (1) - 1.3%, (2) - 11.4%, (3)-27.3%, (4) - 50 %, (P<0.001); Aristotle basic score (1) - 1.1%, (2) - 12.2%, (3) - 34%, (4) - 64.7%, (P<0.001); and STS-EACTS mortality score (1) - 5.5 %, (2) - 13.6%, (3) - 18.7%, (4) - 35.8%, (P<0.001). The three models had similar accuracy by calculating the area under the ROC curve: RACHS-1- 0.738; STS-EACTS-0.739; Aristotle- 0.766.

CONCLUSION

The three models of stratification of complexity currently available in the literature are useful with different mortalities between the proposed categories with similar discriminatory capacity for hospital mortality.

Proxy markers of serum retinol concentration, used alone and in combination, to assess population vitamin A status in Kenyan children: a cross-sectional study

BACKGROUND

Serum retinol concentration determined by high-performance liquid chromatography (HPLC) is recommended by the World Health Organization to assess population vitamin A status. This assay is expensive, technically demanding and rarely available in developing countries. Our objective was a) to assess the diagnostic performance of proxy markers in detecting vitamin A deficiency and b) to derive decision rules based on these markers to estimate vitamin A deficiency prevalence.

METHODS

A survey was conducted in 15 rural primary schools in Eastern Province, Kenya, with 375 children aged 6 to 12 years (25 randomly selected per school). Serum retinol concentration <0.70 μmol/L by HPLC was used to define vitamin A deficiency. Proxy markers for vitamin A deficiency were serum concentrations of retinol binding protein (RBP), transthyretin, retinol measured by fluorometry and RBP:transthyretin molar ratio.

RESULTS

The prevalence of vitamin A deficiency (HPLC) was 18%. Transthyretin and RBP showed the best diagnostic performance individually, with area-under-the-curve (AUC) values of 0.96 and 0.93. When combined, and with C-reactive protein added, the AUC increased to 0.98. A simple decision rule {(-15.277 × [RBP, μmol/L] - 7.013 × [Transthyretin, μmol/L] + 0.367 × [C-reactive protein, mg/L] + 24.714) > 0.496} yielded prevalence estimates of vitamin A deficiency that is unbiased by diagnostic error.

CONCLUSIONS

The combination of transthyretin, RBP and C-reactive protein concentrations could eventually replace retinol concentration by HPLC in resource-poor settings as the preferred method to assess the population burden of vitamin A deficiency.

Identifying and enhancing risk thresholds in the detection of elder financial abuse: a signal detection analysis of professionals' decision making

BACKGROUND

Financial abuse of elders is an under acknowledged problem and professionals' judgements contribute to both the prevalence of abuse and the ability to prevent and intervene. In the absence of a definitive "gold standard" for the judgement, it is desirable to try and bring novice professionals' judgemental risk thresholds to the level of competent professionals as quickly and effectively as possible. This study aimed to test if a training intervention was able to bring novices' risk thresholds for financial abuse in line with expert opinion.

METHODS

A signal detection analysis, within a randomised controlled trial of an educational intervention, was undertaken to examine the effect on the ability of novices to efficiently detect financial abuse. Novices (n = 154) and experts (n = 33) judged "certainty of risk" across 43 scenarios; whether a scenario constituted a case of financial abuse or not was a function of expert opinion. Novices (n = 154) were randomised to receive either an on-line educational intervention to improve financial abuse detection (n = 78) or a control group (no on-line educational intervention, n = 76). Both groups examined 28 scenarios of abuse (11 "signal" scenarios of risk and 17 "noise" scenarios of no risk). After the intervention group had received the on-line training, both groups then examined 15 further scenarios (5 "signal" and 10 "noise" scenarios).

RESULTS

Experts were more certain than the novices, pre (Mean 70.61 vs. 58.04) and post intervention (Mean 70.84 vs. 63.04); and more consistent. The intervention group (mean 64.64) were more certain of abuse post-intervention than the control group (mean 61.41, p = 0.02). Signal detection analysis of sensitivity (A´) and bias (C) revealed that this was due to the intervention shifting the novices' tendency towards saying "at risk" (C post intervention -.34) and away from their pre intervention levels of bias (C-.12). Receiver operating curves revealed more efficient judgments in the intervention group.

CONCLUSION

An educational intervention can improve judgements of financial abuse amongst novice professionals.

Accuracy of the Berger-Exner test for detecting third-order selection bias in randomised controlled trials: a simulation-based investigation

BACKGROUND

Randomised controlled trials (RCT) are highly influential upon medical decisions. Thus RCTs must not distort the truth. One threat to internal trial validity is the correct prediction of future allocations (selection bias). The Berger-Exner test detects such bias but has not been widely utilized in practice. One reason for this non-utilisation may be a lack of information regarding its test accuracy. The objective of this study is to assess the accuracy of the Berger-Exner test on the basis of relevant simulations for RCTs with dichotomous outcomes.

METHODS

Simulated RCTs with various parameter settings were generated, using R software, and subjected to bias-free and selection bias scenarios. The effect size inflation due to bias was quantified. The test was applied in both scenarios and the pooled sensitivity and specificity, with 95% confidence intervals for alpha levels of 1%, 5%, and 20%, were computed. Summary ROC curves were generated and the relationships of parameters with test accuracy were explored.

RESULTS

An effect size inflation of 71% - 99% was established. Test sensitivity was 1.00 (95% CI: 0.99 - 1.00) for alpha level 1%, 5%, and 20%; test specificity was 0.94 (95% CI: 0.93 - 0.96); 0.82 (95% CI: 0.80 - 0.84), and 0.56 (95% CI: 0.54 - 0.58) for alpha 1%, 5%, and 20%, respectively. Test accuracy was best with the maximal procedure used with a maximum tolerated imbalance (MTI) = 2 as the randomisation method at alpha 1%.

CONCLUSIONS

The results of this simulation study suggest that the Berger-Exner test is generally accurate for identifying third-order selection bias.

Long working hours and work-related cerebro-cardiovascular disease in Korea

The aim of the present study was to determine a good discriminatory cutoff for long working hours as a surrogate of chronic overload at work, which is associated with the approval of workers' compensation claims for work-related cerebro-cardiovascular disease (WR-CVD) in Korea. We evaluated weekly working hours for four weeks prior to the onset of disease for all manufacturing industry claimants (N=319) of WR-CVD in 2010. The discrimination of long working hours in predicting approval of worker's compensation pertaining to WR-CVD was compared across cases. The cutoff was calculated with sensitivity, specificity, and the area under the curve with 95% CI using the receiver operating curve (ROC) method. The cutoff point was thus calculated to be 60.75 h (AUC=0.89, 95% CI [0.84-0.93]), showing a sensitivity value of 65% and specificity of 94%. This is the first study to report that long working hours could be a predictor with good discrimination and high specificity of approval of WR-CVD cases. In Korea, long working hours and widespread chronic overload at work are recognized as a social problem. Our study results suggest an appropriate cutoff for working hours as an indicator of chronic overload for the purpose of approving claims of WR-CVD. Furthermore, these results could contribute to improving the consistency of evaluation.

Predictive accuracy of risk factors and markers: a simulation study of the effect of novel markers on different performance measures for logistic regression models

The change in c-statistic is frequently used to summarize the change in predictive accuracy when a novel risk factor is added to an existing logistic regression model. We explored the relationship between the absolute change in the c-statistic, Brier score, generalized R(2) , and the discrimination slope when a risk factor was added to an existing model in an extensive set of Monte Carlo simulations. The increase in model accuracy due to the inclusion of a novel marker was proportional to both the prevalence of the marker and to the odds ratio relating the marker to the outcome but inversely proportional to the accuracy of the logistic regression model with the marker omitted. We observed greater improvements in model accuracy when the novel risk factor or marker was uncorrelated with the existing predictor variable compared with when the risk factor has a positive correlation with the existing predictor variable. We illustrated these findings by using a study on mortality prediction in patients hospitalized with heart failure. In conclusion, the increase in predictive accuracy by adding a marker should be considered in the context of the accuracy of the initial model.

The impact of maternal characteristics on the moderately premature infant: an antenatal maternal transport clinical prediction rule

OBJECTIVE

Moderately premature infants, defined here as those born between 30⁰/₇ and 34⁶/₇ weeks gestation, comprise 3.9% of all births in the United States and 32% of all preterm births. Although long-term outcomes for these infants are better than for less mature infants, morbidity and mortality are still substantially increased in comparison with infants born at term. There is an added survival benefit resulting from birth at a tertiary neonatal care center, and although many of these infants require tertiary level care, delivery at lower level hospitals and subsequent neonatal transfer are still common. Our primary aim was to determine the impact of maternal characteristics and antenatal medical management on the early neonatal course of the moderately premature infant. The secondary aim was to create a clinical prediction rule to determine which infants require intubation and mechanical ventilation in the first 24 h of life. Such a prediction rule could inform the decision to transfer maternal-fetal patients before delivery to a facility with a Level III neonatal intensive care unit (NICU), where optimal care could be provided without the requirement for a neonatal transfer.

STUDY DESIGN

Data for this analysis came from the cohort of infants in the Moderately Premature Infant Project (MPIP) database, a multicenter cohort study of 850 infants born at gestational age 30⁰/₇ and 34⁶/₇ weeks, with birth weight between 591 to 3540 g. [corrected], who were discharged to home alive. We built a logistic regression model to identify maternal characteristics associated with need for tertiary care, as measured by administration of surfactant. Using statistically significant covariates from this model, we then created a numerical decision rule to predict need for tertiary care.

RESULT

In multivariate modeling, four factors were associated with reduction in the need for tertiary care, including non-White race (odds ratio (OR)=0.5, (0.3, 0.7)), older gestational age, female gender (OR=0.6 (0.4, 0.8)) and use of antenatal corticosteroids (OR=0.5, (0.3, 0.8)). The clinical prediction rule to discriminate between infants who received surfactant, versus those who did not, had an area under the curve of 0.77 (0.73, 0.8).

CONCLUSION

Four antenatal risk factors are associated with a requirement for Level III NICU care as defined by the need for surfactant administration. Future analyses will examine a broader spectrum of antenatal characteristics and revalidate the prediction rule in an independent cohort.

Confidence intervals and bands for the binormal ROC curve revisited

Two types of confidence intervals (CIs) and confidence bands (CBs) for the receiver operating characteristic (ROC) curve are studied: pointwise CIs and simultaneous CBs. An optimized version of the pointwise CI with the shortest width is developed. A new ellipse-envelope simultaneous CB for the ROC curve is suggested as an adaptation of the Working-Hotelling-type CB implemented in a paper by Ma and Hall (1993). Statistical simulations show that our ellipse-envelope CB covers the true ROC curve with a probability close to nominal while the coverage probability of the Ma and Hall CB is significantly smaller. Simulations also show that our CI for the area under the ROC curve is close to nominal while the coverage probability of the CI suggested by Hanley and McNail (1982) uniformly overestimates the nominal value. Two examples illustrate our simultaneous ROC bands: radiation dose estimation from time to vomiting and discrimination of breast cancer from benign abnormalities using electrical impedance measurements.

Analysis of biomarker data: logs, odds ratios, and receiver operating characteristic curves

PURPOSE OF REVIEW

We discuss two data analysis issues for studies that use binary clinical outcomes (whether or not an event occurred): the choice of an appropriate scale and transformation when biomarkers are evaluated as explanatory factors in logistic regression and assessing the ability of biomarkers to improve prediction accuracy for event risk.

RECENT FINDINGS

Biomarkers with skewed distributions should be transformed before they are included as continuous covariates in logistic regression models. The utility of new biomarkers may be assessed by measuring the improvement in predicting event risk after adding the biomarkers to an existing model. The area under the receiver operating characteristic (ROC) curve (C-statistic) is often cited; it was developed for a different purpose, however, and may not address the clinically relevant questions. Measures of risk reclassification and risk prediction accuracy may be more appropriate.

SUMMARY

The appropriate analysis of biomarkers depends on the research question. Odds ratios obtained from logistic regression describe associations of biomarkers with clinical events; failure to accurately transform the markers, however, may result in misleading estimates. Although the C-statistic is often used to assess the ability of new biomarkers to improve the prediction of event risk, other measures may be more suitable.

A parametric ROC model-based approach for evaluating the predictiveness of continuous markers in case-control studies

The predictiveness curve shows the population distribution of risk endowed by a marker or risk prediction model. It provides a means for assessing the model's capacity for stratifying the population according to risk. Methods for making inference about the predictiveness curve have been developed using cross-sectional or cohort data. Here we consider inference based on case-control studies, which are far more common in practice. We investigate the relationship between the ROC curve and the predictiveness curve. Insights about their relationship provide alternative ROC interpretations for the predictiveness curve and for a previously proposed summary index of it. Next the relationship motivates ROC based methods for estimating the predictiveness curve. An important advantage of these methods over previously proposed methods is that they are rank invariant. In addition they provide a way of combining information across populations that have similar ROC curves but varying prevalence of the outcome. We apply the methods to prostate-specific antigen (PSA), a marker for predicting risk of prostate cancer.

Use of body mass index and percentage overweight cutoffs to screen Japanese children and adolescents for obesity-related risk factors

BACKGROUND

Cutoffs based on percentage overweight (POW) are used for screening students in Japan; however, body mass index (BMI) is more common in the rest of the world. To screen for risk factors related to obesity among Japanese primary and secondary school students, we compared fasting and postprandial values, and the receiver operating characteristic (ROC) curves for the POW and BMI criteria.

METHODS

The subjects were students aged 10 and 13 years living in Shunan City, Japan between 2006 and 2008 (n = 6566). POW and International Obesity Taskforce (IOTF) BMI criteria were used to screen for obesity-related risk factors. The lower (20%, 18-year-old equivalent: 25 kg/m(2)) and higher (50%, 18-year-old equivalent: 30 kg/m(2)) cutoffs were examined, and ROC curves were drawn.

RESULTS

Fasting cholesterol levels were higher than postprandial levels. The prevalences of overweight/obesity were 6.6% to 10.0% using the lower cutoff and 0.6% to 5.0% using the higher cutoff. Among overweight subjects under fasting conditions, dyslipidemia was present in 12% to 52%, hypertriglyceridemia in 29% to 54%, hyperglycemia in 11% to 21%, and hypertension in 15% to 40%. Although the use of the lower and higher POW cutoffs resulted in lower sensitivity and the higher specificity, the POW and BMI ROC curves largely overlapped. However, for girls aged 10 years, the POW curve for >or=3 risks factors was lower than that of the latter (P = 0.013).

CONCLUSIONS

For Japanese aged 10 and 13 years, both BMI and POW are useful for risk factor screening. However, subjects may be misclassified with dyscholesterolemia if postprandial blood samples are used.

Relationship between patient satisfaction and objective functional outcome after surgical treatment for distal radius fractures

STUDY DESIGN

Prospective cohort.

INTRODUCTION

Patient satisfaction is increasingly used as a metric of health care outcomes. The relationship between patient satisfaction and functional outcomes metrics is understudied.

PURPOSE

To determine the minimum recovery needed in grip strength, key pinch strength, and arc of motion needed for patient satisfaction after treatment of distal radius fracture (DRF) with volar locking plating system placement.

METHODS

A prospective cohort of 125 DRF patients was evaluated three months after surgery for grip strength, key pinch strength, wrist arc of motion, and satisfaction with hand strength and wrist arc of motion. Receiver operating characteristic curves were constructed using patient satisfaction items as the "gold standard" and each functional measure of outcome as a predictor.

RESULTS

We found that the optimal cutpoints to distinguish satisfaction from dissatisfaction occurred when patients had recovered 65% of their grip strength, 87% of their key grip strength, and 95% of the wrist arc of motion, as measured as percents of their uninjured wrists.

CONCLUSIONS

A much greater wrist range of motion must be recovered for patients to be satisfied than what is needed to perform activities of daily living.

LEVEL OF EVIDENCE

Diagnosis level 2.

The predictive receiver operating characteristic curve for the joint assessment of the positive and negative predictive values

Binary test outcomes typically result from dichotomizing a continuous test variable, observable or latent. The effect of the threshold for test positivity on test sensitivity and specificity has been studied extensively in receiver operating characteristic (ROC) analysis. However, considerably less attention has been given to the study of the effect of the positivity threshold on the predictive value of a test. In this paper we present methods for the joint study of the positive (PPV) and negative predictive values (NPV) of diagnostic tests. We define the predictive receiver operating characteristic (PROC) curve that consists of all possible pairs of PPV and NPV as the threshold for test positivity varies. Unlike the simple trade-off between sensitivity and specificity exhibited in the ROC curve, the PROC curve displays what is often a complex interplay between PPV and NPV as the positivity threshold changes. We study the monotonicity and other geometric properties of the PROC curve and propose summary measures for the predictive performance of tests. We also formulate and discuss regression models for the estimation of the effects of covariates.

Optimal cutoff values for overweight: using body mass index to predict incidence of hypertension in 18- to 65-year-old Chinese adults

Studies aimed at identifying BMI cutoffs representing increased diseased risk for Asians are typically based on cross-sectional studies. This study determines an optimal BMI cutoff for overweight that represents elevated incidence of hypertension in Chinese adults with data from the China Health and Nutrition Survey 2000-2004 prospective cohort. Cumulative incidence was calculated by dividing new cases of hypertension over the study period by the total at-risk population, aged 18-65 y, in 2000. Sex-specific receiver operating characteristic curves were used to assess the sensitivity and specificity of BMI as a predictor of hypertension incidence. Four-year cumulative incidences of hypertension (13% for women and 19% for men) were related (P < 0.005) to the increase in BMI. The crude area under the curves (AUC) were 0.62 (95% CI: 0.59-0.65) and 0.62 (95% CI: 0.58-0.65) for men and women, respectively; the age-adjusted AUC were 0.68 (95% CI: 0.65-0.70) and 0.71 (95% CI: 0.68-0.74) for men and women, respectively. A BMI of 23.5 kg/m(2) for women and 22.5 kg/m(2) for men provided the highest sensitivity and specificity (60%). The finding was consistent in different age groups. A BMI level of 25 kg/m(2) provided lower sensitivities (36% for women and 29% for men) with higher specificities (80% for women and 85% for men). Our study supported the hypothesis that the BMI cutoff to define overweight should be lower in Chinese than that in Western populations.

Predictors of death or bronchopulmonary dysplasia in preterm infants with respiratory failure

OBJECTIVES

To identify the variables that predict death/physiologic bronchopulmonary dysplasia (BPD) in preterm infants with severe respiratory failure.

STUDY DESIGN

The study was a secondary analysis of data from the NICHD Neonatal Research Network trial of inhaled nitric oxide (iNO) in preterm infants. Stepwise logistic regression models and Classification and Regression Tree (CART) models were developed for the outcome of death or physiologic BPD (O(2) at 36 weeks post-menstrual age).

RESULT

Death and/or BPD was associated with lower birth weight, higher oxygen requirement, male gender, additional surfactant doses, higher oxygenation index and outborn status, but not the magnitude of response in PaO(2) to iNO. The positive predictive value of the CART model was 82% at 95% sensitivity.

CONCLUSIONS

The major factors associated with death/BPD were an increased severity of respiratory failure, lower birth weight, male gender and outborn status, but not the magnitude of initial response to iNO.

The performance of the Japanese version of the K6 and K10 in the World Mental Health Survey Japan

Two new screening scales for psychological distress, the K6 and K10, have been developed using the item response theory and shown to outperform existing screeners in English. We developed their Japanese versions using the standard back-translaton method and included them in the World Mental Health Survey Japan (WMH-J), which is a psychiatric epidemiologic study conducted in seven communities across Japan with 2436 participants. The WMH-J used the WMH Survey Initiative version of the Composite International Diagnostic Interview (CIDI) to assess the 30-day Diagnostic and Statistical Manual of Mental Disorders--Fourth Edition (DSM-IV). Performance of the two screening scales in detecting DSM-IV mood and anxiety disorders, as assessed by the areas under receiver operating characteristic curves (AUCs), was excellent, with values as high as 0.94 (95% confidence interval = 0.88 to 0.99) for K6 and 0.94 (0.88 to 0.995) for K10. Stratum-specific likelihood ratios (SSLRs), which express screening test characteristics and can be used to produce individual-level predicted probabilities of being a case from screening scale scores and pretest probabilities in other samples, were strikingly similar between the Japanese and the original versions. The Japanese versions of the K6 and K10 thus demonstrated screening performances essentially equivalent to those of the original English versions.

Appropriate waist circumference cutoff values for persons with multiple cardiovascular risk factors in Japan: a large cross-sectional study

BACKGROUND

In Japan, the current standard waist circumference cutoff value for persons with multiple cardiovascular risk factors remains controversial. In this study we aimed to analyze the health-check examination data from a large Japanese population and propose a revised waist circumference cutoff value.

METHODS

Subjects of this study were 12,725 adults who underwent a health-check by thorough medical examination between April 2006 and March 2007. Medical examinations included measurement of waist circumference, fasting blood triglycerides, HDL cholesterol, glucose concentrations, blood pressure and collection of demographic characteristics. Receiver operating characteristic (ROC) curve analysis was utilized to find appropriate waist circumference cutoff values in relation to multiple cardiovascular risk factors with two or more of the following: dyslipidemia (hypertriglyceridemia or low HDL cholesterol), hypertension, and hyperglycemia defined by the Japanese criteria of metabolic syndrome.

RESULTS

The average age of the subjects was 50.7 years (standard deviation [SD]: 8.8) for men and 49.7 years (SD: 8.6) for women. ROC curve analysis showed maximum sensitivity plus specificity at a waist circumference of 87 cm in men (0.66 and 0.62, respectively) and 83 cm in women (0.73 and 0.70). When analyzed by ten-year age groups, the ROC curves for younger age groups were shifted up and to the left compared to older age groups, but associations between cutoff values and age were not clear.

CONCLUSION

In Japan, the appropriate cutoff value of waist circumference for persons with multiple cardiovascular risk factors is 87 cm for men and 83 cm for women.

Clinical data predict neurodevelopmental outcome better than head ultrasound in extremely low birth weight infants

OBJECTIVE

To determine the relative contribution of clinical data versus head ultrasound scanning (HUS) in predicting neurodevelopmental impairment (NDI) in extremely low birth weight infants.

STUDY DESIGN

A total of 2103 extremely low birth weight infants (<1000 g) admitted to a National Institute of Child Health and Human Development Neonatal Research Network center who underwent HUS within the first 28 days, a repeat one around 36 weeks' postmenstrual age, and neurodevelopmental assessment at 18 to 22 months corrected age were selected. Multivariate logistic regression models were developed with clinical or HUS variables. The primary outcome was the predictive abilities of the HUS performed before 28 days after birth and closer to 36 weeks postmenstrual age, either alone or in combination with "Early" and "Late" clinical variables.

RESULTS

Models with clinical variables alone predicted NDI better than models with only HUS variables at both 28 days and 36 weeks (both P < .001), and the addition of the HUS data did not improve prediction. NDI was absent in 30% and 28% of the infants with grade IV intracranial hemorrhage or periventricular leukomalacia, respectively, but was present in 39% of the infants with a normal HUS result.

CONCLUSIONS

Clinical models were better than HUS models in predicting neurodevelopment.

An introduction to biomarkers: applications to chronic kidney disease

Diagnosis and management of chronic kidney disease (CKD) will be characterized in the future by an increasing use of biomarkers-quantitative indicators of biologic or pathologic processes that vary continuously with progression of the process. "Classical" biomarkers of CKD progression include quantitative proteinuria, the percentage of sclerotic glomeruli or fractional interstitial fibrosis. New candidate biomarkers (e.g., urinary proteomic patterns) are being developed based on both mechanistic and "shotgun" approaches. Validation of potential biomarkers in prospective studies as surrogate endpoints for hard clinical outcomes is often complicated by the long lag time to the ultimate clinical outcome (e.g., end-stage renal disease). The very dense data sets that result from shotgun approaches on small numbers of patients carry a significant risk of model overfitting, leading to spurious associations. New analytic methods can help to decrease this risk. It is likely that clinical practice will come to depend increasingly on multiplex (vector) biomarkers used in conjunction with risk markers in early diagnosis as well as to guide therapy.

Reliability and validity of the severe impairment battery (SIB) in Korean dementia patients

This study was conducted to examine the reliability, validity and clinical utility of the Severe Impairment Battery (SIB) for a Korean population. 69 dementia patients with Clinical Dementia Rating (CDR) stages 2 or 3 were participated in this study. The SIB, Korean version-Mini Mental State Examination (K-MMSE), CDR, and Seoul-Activities of Daily Living (S-ADL) were administered. The validity of the SIB was confirmed by evaluating the correlation coefficients between the SIB and K-MMSE, CDR, S-ADL, which were found to be significant. Cronbach's alpha for the total SIB score and each subscale score showed high significance, and the item-total correlation for each subscale was also acceptable. The test-retest correlation for the total SIB score and subscale scores were significant, except for the praxis and orienting to name. The total SIB score and subscale scores were examined according to CDR. The results suggest that the SIB can differentiate the poor performances of severely impaired dementia patients. On the basis of the receiver operating characteristic (ROC), it can be concluded that the SIB is able to accurately discriminate between CDR 2 and 3 patients. The results of this study suggest that the SIB is a reliable and valid instrument for evaluating severe dementia patients in Korean population.

Scoring method for early prediction of neonatal chronic lung disease using modified respiratory parameters

In our previous study, we have demonstrated that peak inspiratory pressure over birth weight (PIP/kg) and mean airway pressure over birth weight (MAP/kg) were more significant risk factors for the development of neonatal chronic lung disease (CLD) than PIP and MAP. We aimed to develop a scoring method using the modified respiratory variables (SMUMRV) to predict CLD at early postnatal period. From 1997 to 1999, a retrospective review was performed for 197 infants <1,500 g for the development of the SMUMRV based on statistical analysis. From 2000 to 2001, calculated scores on day 4, 7 and 10 of life were obtained prospectively for 107 infants <1,500 g. Predictive values and the area under the receiver operator characteristic curve (AUC) were determined and compared with the result of the previous regression model. Gestational age, birth weight, 5 min Apgar score, PIP/kg at 12 hr of age, fractional inspired oxygen (FiO2), MAP/kg, modified oxygenation index and ventilatory mode were selected as parameters of SMUMRV. No significant differences of AUCs were found between the SMUMRV and the Yoder model. It is likely that our scoring method provides reliable values for predicting the development of CLD in very low birth weight infants.

Prostate-specific antigen testing accuracy in community practice

BACKGROUND

Most data on prostate-specific antigen (PSA) testing come from urologic cohorts comprised of volunteers for screening programs. We evaluated the diagnostic accuracy of PSA testing for detecting prostate cancer in community practice.

METHODS

PSA testing results were compared with a reference standard of prostate biopsy. Subjects were 2,620 men 40 years and older undergoing (PSA) testing and biopsy from 1/1/95 through 12/31/98 in the Albuquerque, New Mexico metropolitan area. Diagnostic measures included the area under the receiver-operating characteristic curve, sensitivity, specificity, and likelihood ratios.

RESULTS

Cancer was detected in 930 subjects (35%). The area under the ROC curve was 0.67 and the PSA cutpoint of 4 ng/ml had a sensitivity of 86% and a specificity of 33%. The likelihood ratio for a positive test (LR+) was 1.28 and 0.42 for a negative test (LR-). PSA testing was most sensitive (90%) but least specific (27%) in older men. Age-specific reference ranges improved specificity in older men (49%) but decreased sensitivity (70%), with an LR+ of 1.38. Lowering the PSA cutpoint to 2 ng/ml resulted in a sensitivity of 95%, a specificity of 20%, and an LR+ of 1.19.

CONCLUSIONS

PSA testing had fair discriminating power for detecting prostate cancer in community practice. The PSA cutpoint of 4 ng/ml was sensitive but relatively non-specific and associated likelihood ratios only moderately revised probabilities for cancer. Using age-specific reference ranges and a PSA cutpoint below 4 ng/ml improved test specificity and sensitivity, respectively, but did not improve the overall accuracy of PSA testing.

Combining ADA, protein and IFN-gamma best allows discrimination between tuberculous and malignant pleural effusion

BACKGROUND

The purpose of this study is to assess the usefulness of various enzymes, cytokines and biochemical studies of pleural fluid for the differential diagnosis of tuberculosis from malignant pleural effusions, and to clarify the role of combining diagnostic tests.

METHODS

The study group included 39 cases with tuberculous effusions and 31 cases with malignant effusions, whose diagnoses were confirmed by pleural biopsy, cytology or microbiological methods. We compared pleural fluid levels of ADA, TNF-alpha, IFN-gamma, IL-2, IL-6, IL-8, pH, protein, glucose, cholesterol, triglyceride, amylase and lactic dehydrogenase between tuberculous and malignant effusions. Using stepwise logistic regression analysis, we evaluated the benefit of combining various parameters. Receiver operating characteristic(ROC) curves of ADA, cytokines and equations generated from regression analyses were plotted and compared with the area under curve(AUC). Cut-off values showing the best diagnostic accuracy were selected and compared.

RESULTS

Compared to malignant effusion, tuberculous effusion showed significantly higher levels of ADA, IFN-gamma, TNF-alpha and IL-2. There was a good correlation between IFN-gamma and TNF-alpha. By stepwise logistic regression analysis, IFN-gamma, protein and ADA were independent variables predicting tuberculous from malignant effusions. The diagnostic accuracy and AUC of regression equation was greater than any other single parameters.

CONCLUSION

For the differential diagnosis of tuberculosis and malignant pleural effusions, combining ADA, protein and IFN-gamma best allows discrimination.