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Dirks NF, den Elzen WPJ, Hillebrand JJ, Jansen HI, Boekel ET, Brinkman J, Buijs MM, Demir AY, Dijkstra IM, Endenburg SC, Engbers P, Gootjes J, Janssen MJW, Kniest-de Jong WHA, Kok MB, Kamphuis S, Kruit A, Michielsen E, Wolthuis A, Boelen A, Heijboer AC. Should we depend on reference intervals from manufacturer package inserts? Comparing TSH and FT4 reference intervals from four manufacturers with results from modern indirect methods and the direct method. Clin Chem Lab Med 2024; 62:1352-1361. [PMID: 38205847 DOI: 10.1515/cclm-2023-1237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 12/30/2023] [Indexed: 01/12/2024]
Abstract
OBJECTIVES Correct interpretation of thyroid function tests relies on correct reference intervals (RIs) for thyroid-stimulating hormone (TSH) and free thyroxine (FT4). ISO15189 mandates periodic verification of RIs, but laboratories struggle with cost-effective approaches. We investigated whether indirect methods (utilizing historical laboratory data) could replace the direct approach (utilizing healthy reference individuals) and compared results with manufacturer-provided RIs for TSH and FT4. METHODS We collected historical data (2008-2022) from 13 Dutch laboratories to re-establish RIs by employing indirect methods, TMC (for TSH) and refineR (for FT4). Laboratories used common automated platforms (Roche, Abbott, Beckman or Siemens). Indirect RIs (IRIs) were determined per laboratory per year and clustered per manufacturer (>1.000.000 data points per manufacturer). Direct RIs (DRIs) were established in 125 healthy individuals per platform. RESULTS TSH IRIs remained robust over the years for all manufacturers. FT4 IRIs proved robust for three manufacturers (Roche, Beckman and Siemens), but the IRI upper reference limit (URL) of Abbott showed a decrease of 2 pmol/L from 2015. Comparison of the IRIs and DRIs for TSH and FT4 showed close agreement using adequate age-stratification. Manufacturer-provided RIs, notably Abbott, Roche and Beckman exhibited inappropriate URLs (overall difference of 0.5-1.0 µIU/mL) for TSH. For FT4, the URLs provided by Roche, Abbott and Siemens were overestimated by 1.5-3.5 pmol/L. CONCLUSIONS These results underscore the importance of RI verification as manufacturer-provided RIs are often incorrect and RIs may not be robust. Indirect methods offer cost-effective alternatives for laboratory-specific or platform-specific verification of RIs.
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Affiliation(s)
- Niek F Dirks
- Endocrine Laboratory, Department of Laboratory Medicine, Amsterdam UMC Location University of Amsterdam, Amsterdam, The Netherlands
- Atalmedial Diagnostic Centers, Amsterdam, The Netherlands
- Department of Clinical Chemistry, Hematology & Immunology, Northwest Clinics, Alkmaar, The Netherlands
| | - Wendy P J den Elzen
- Laboratory Specialized Diagnostics & Research, Department of Laboratory Medicine, Amsterdam UMC Location University of Amsterdam, Amsterdam, The Netherlands
- Amsterdam Public Health Research Institute, Amsterdam, The Netherlands
| | - Jacquelien J Hillebrand
- Endocrine Laboratory, Department of Laboratory Medicine, Amsterdam UMC Location University of Amsterdam, Amsterdam, The Netherlands
- Amsterdam Gastroenterology, Endocrinology & Metabolism, Amsterdam, The Netherlands
| | - Heleen I Jansen
- Endocrine Laboratory, Department of Laboratory Medicine, Amsterdam UMC Location University of Amsterdam, Amsterdam, The Netherlands
- Amsterdam Gastroenterology, Endocrinology & Metabolism, Amsterdam, The Netherlands
- Endocrine Laboratory, Department of Laboratory Medicine, Amsterdam UMC Location Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Edwin Ten Boekel
- Department of Clinical Chemistry, Hematology & Immunology, Northwest Clinics, Alkmaar, The Netherlands
| | - Jacoline Brinkman
- Department of Clinical Chemistry, St. Jansdal Hospital, Harderwijk, The Netherlands
| | | | - Ayse Y Demir
- Laboratory for Clinical Chemistry and Hematology, Meander Medical Center, Amersfoort, The Netherlands
| | - Ineke M Dijkstra
- Clinical Chemistry, St Antonius Hospital, Nieuwegein, The Netherlands
| | - Silvia C Endenburg
- Department of Clinical Chemistry and Hematology, Dicoon, Gelderse Vallei Hospital, Ede, The Netherlands
| | - Paula Engbers
- Department of Clinical Chemistry, Treant Care Group, Hoogeveen, The Netherlands
| | | | - Marcel J W Janssen
- Laboratory of Clinical Chemistry and Hematology, VieCuri Medical Center, Venlo, The Netherlands
| | | | - Maarten B Kok
- Saltro Diagnostic Center, Unilabs Netherlands, Utrecht, The Netherlands
| | - Stephan Kamphuis
- Eurofins Clinical Diagnostics, Gelre Hospitals, Apeldoorn, The Netherlands
| | - Adrian Kruit
- Medical Laboratory, Nij Smellinghe Hospital, Drachten, The Netherlands
| | | | - Albert Wolthuis
- Stichting Certe Medische Diagnostiek en Advies, Groningen, The Netherlands
| | - Anita Boelen
- Endocrine Laboratory, Department of Laboratory Medicine, Amsterdam UMC Location University of Amsterdam, Amsterdam, The Netherlands
- Amsterdam Gastroenterology, Endocrinology & Metabolism, Amsterdam, The Netherlands
- Amsterdam Reproduction & Development Research Institute, Amsterdam, The Netherlands
| | - Annemieke C Heijboer
- Endocrine Laboratory, Department of Laboratory Medicine, Amsterdam UMC Location University of Amsterdam, Amsterdam, The Netherlands
- Amsterdam Gastroenterology, Endocrinology & Metabolism, Amsterdam, The Netherlands
- Amsterdam Reproduction & Development Research Institute, Amsterdam, The Netherlands
- Endocrine Laboratory, Department of Laboratory Medicine, Amsterdam UMC Location Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
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2
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Ma C, Yu Z, Qiu L. Development of next-generation reference interval models to establish reference intervals based on medical data: current status, algorithms and future consideration. Crit Rev Clin Lab Sci 2024; 61:298-316. [PMID: 38146650 DOI: 10.1080/10408363.2023.2291379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 11/30/2023] [Indexed: 12/27/2023]
Abstract
Evidence derived from laboratory medicine plays a pivotal role in the diagnosis, treatment monitoring, and prognosis of various diseases. Reference intervals (RIs) are indispensable tools for assessing test results. The accuracy of clinical decision-making relies directly on the appropriateness of RIs. With the increase in real-world studies and advances in computational power, there has been increased interest in establishing RIs using big data. This approach has demonstrated cost-effectiveness and applicability across diverse scenarios, thereby enhancing the overall suitability of the RI to a certain extent. However, challenges persist when tests results are influenced by age and sex. Reliance on a single RI or a grouping of RIs based on age and sex can lead to erroneous interpretation of results with significant implications for clinical decision-making. To address this issue, the development of next generation of reference interval models has arisen at an historic moment. Such models establish a curve relationship to derive continuously changing reference intervals for test results across different age and sex categories. By automatically selecting appropriate RIs based on the age and sex of patients during result interpretation, this approach facilitates clinical decision-making and enhances disease diagnosis/treatment as well as health management practices. Development of next-generation reference interval models use direct or indirect sampling techniques to select reference individuals and then employed curve fitting methods such as splines, polynomial regression and others to establish continuous models. In light of these studies, several observations can be made: Firstly, to date, limited interest has been shown in developing next-generation reference interval models, with only a few models currently available. Secondly, there are a wide range of methods and algorithms for constructing such models, and their diversity may lead to confusion. Thirdly, the process of constructing next-generation reference interval models can be complex, particularly when employing indirect sampling techniques. At present, normative documents pertaining to the development of next-generation reference interval models are lacking. In summary, this review aims to provide an overview of the current state of development of next-generation reference interval models by defining them, highlighting inherent advantages, and addressing existing challenges. It also describes the process, advanced algorithms for model building, the tools required and the diagnosis and validation of models. Additionally, a discussion on the prospects of utilizing big data for developing next-generation reference interval models is presented. The ultimate objective is to equip clinical laboratories with the theoretical framework and practical tools necessary for developing and optimizing next-generation reference interval models to establish next-generation reference intervals while enhancing the use of medical data resources to facilitate precision medicine.
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Affiliation(s)
- Chaochao Ma
- Department of Laboratory Medicine, Peking Union Medical College, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
- Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, Beijing, China
| | - Zheng Yu
- Department of Operations Research and Financial Engineering, Princeton University, Princeton University, Princeton, NJ, USA
| | - Ling Qiu
- Department of Laboratory Medicine, Peking Union Medical College, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
- State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Science, Beijing, China
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3
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Zheng J, Tang Y, Peng X, Zhao J, Chen R, Yan R, Peng Y, Zhang W. Indirect estimation of pediatric reference interval via density graph deep embedded clustering. Comput Biol Med 2024; 169:107852. [PMID: 38134750 DOI: 10.1016/j.compbiomed.2023.107852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 11/10/2023] [Accepted: 12/11/2023] [Indexed: 12/24/2023]
Abstract
Establishing reference intervals (RIs) for pediatric patients is crucial in clinical decision-making, and there is a critical gap of pediatric RIs in China. However, the direct sampling technique for establishing RIs is resource-intensive and ethically challenging. Indirect estimation methods, such as unsupervised clustering algorithms, have emerged as potential alternatives for predicting reference intervals. This study introduces deep graph clustering methods into indirect estimation of pediatric reference intervals. Specifically, we propose a Density Graph Deep Embedded Clustering (DGDEC) algorithm, which incorporates a density feature extractor to enhance sample representation and provides additional perspectives for distinguishing different levels of health status among populations. Additionally, we construct an adjacency matrix by computing the similarity between samples after feature enhancement. The DGDEC algorithm leverages the adjacency matrix to capture the interrelationships between patients and divides patients into different groups, thereby estimating reference intervals for the potential healthy population. The experimental results demonstrate that when compared to other indirect estimation techniques, our method ensures the predicted pediatric reference intervals in different age and gender groups are closer to the true values while maintaining good generalization performance. Additionally, through ablation experiments, our study confirms that the similarity between patients and the multi-scale density features of samples can effectively describe the potential health status of patients.
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Affiliation(s)
- Jianguo Zheng
- State Key Laboratory of Multimodal Artificial Intelligence Systems, Institute of Automation, Chinese Academy of Sciences, Beijing, China.
| | - Yongqiang Tang
- State Key Laboratory of Multimodal Artificial Intelligence Systems, Institute of Automation, Chinese Academy of Sciences, Beijing, China.
| | - Xiaoxia Peng
- Center for Clinical Epidemiology and Evidence-Based Medicine, National Center for Children's Health, Beijing Children's Hospital, Capital Medical University, Beijing, China.
| | - Jun Zhao
- Information Center, National Center for Children's Health, Beijing Children's Hospital, Capital Medical University, Beijing, China.
| | - Rui Chen
- State Key Laboratory of Multimodal Artificial Intelligence Systems, Institute of Automation, Chinese Academy of Sciences, Beijing, China.
| | - Ruohua Yan
- Center for Clinical Epidemiology and Evidence-Based Medicine, National Center for Children's Health, Beijing Children's Hospital, Capital Medical University, Beijing, China.
| | - Yaguang Peng
- Center for Clinical Epidemiology and Evidence-Based Medicine, National Center for Children's Health, Beijing Children's Hospital, Capital Medical University, Beijing, China.
| | - Wensheng Zhang
- State Key Laboratory of Multimodal Artificial Intelligence Systems, Institute of Automation, Chinese Academy of Sciences, Beijing, China.
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Chen J, Fan L, Yang Z, Yang D. Comparison of results and age-related changes in establishing reference intervals for CEA, AFP, CA125, and CA199 using four indirect methods. Pract Lab Med 2024; 38:e00353. [PMID: 38221990 PMCID: PMC10787276 DOI: 10.1016/j.plabm.2023.e00353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 12/18/2023] [Accepted: 12/20/2023] [Indexed: 01/16/2024] Open
Abstract
•The reference intervals calculated using RefineR, Kosmic, TMC, and non-parametric methods are similar.•TMC algorithm is more robust, demonstrates a high pass rate among the four methods and has the ability to automatically isolate outliers.•The reference intervals of CA125 and CA199 showed significant differences between age and sex.
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Affiliation(s)
- Juping Chen
- Department of Laboratory Medicine, Liangzhu Branch of the First Affiliated Hospital of Zhejiang University, Zhejiang, China
- School of Public Health, Zhejiang University School of Medicine, Zhejiang, China
| | - Lina Fan
- Department of Laboratory Medicine, The First Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang, China
| | - Zheng Yang
- Department of Laboratory Medicine, The First Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang, China
| | - Dagan Yang
- Department of Laboratory Medicine, The First Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang, China
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Cervinski MA, Bietenbeck A, Katayev A, Loh TP, van Rossum HH, Badrick T. Advances in clinical chemistry patient-based real-time quality control (PBRTQC). Adv Clin Chem 2023; 117:223-261. [PMID: 37973321 DOI: 10.1016/bs.acc.2023.08.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
Patient-Based Real-Time Quality Control involves monitoring an assay using patient samples rather than external material. If the patient population does not change, then a shift in the long-term assay population results represents the introduction of a change in the assay. The advantages of this approach are that the sample(s) are commutable, it is inexpensive, the rules are simple to interpret and there is virtually continuous monitoring of the assay. The disadvantages are that the laboratory needs to understand their patient population and how they may change during the day, week or year and the initial change of mindset required to adopt the system. The concept is not new, having been used since the 1960s and widely adopted on hematology analyzers in the mid-1970s. It was not widely used in clinical chemistry as there were other stable quality control materials available. However, the limitations of conventional quality control approaches have become more evident. There is a greater understanding of how to collect and use patient data in real time and a range of powerful algorithms which can identify changes in assays. There are more assays on more samples being run. There is also a greater interest in providing a theoretical basis for the validation and integration of these techniques into routine practice.
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Affiliation(s)
- Mark A Cervinski
- Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, and the Geisel School of Medicine at Dartmouth, Hanover, NH, United States
| | - Andreas Bietenbeck
- Institut für Klinische Chemie und Pathobiochemie Klinikum, Munich, Germany
| | - Alex Katayev
- Laboratory Corporation of America Holdings, Elon, Burlington, NC, United States
| | | | - Huub H van Rossum
- The Netherlands Cancer Institute, Amsterdam, The Netherlands; Huvaros, The Netherlands
| | - Tony Badrick
- RCPA Quality Assurance Programs, St Leonards, Sydney, Australia.
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Doyle K, Bunch DR. Reference intervals: past, present, and future. Crit Rev Clin Lab Sci 2023; 60:466-482. [PMID: 37036018 DOI: 10.1080/10408363.2023.2196746] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 03/03/2023] [Accepted: 03/24/2023] [Indexed: 04/11/2023]
Abstract
Clinical laboratory test results alone are of little value in diagnosing, treating, and monitoring health conditions; as such, a clinically actionable cutoff or reference interval is required to provide context for result interpretation. Healthcare practitioners base their diagnoses, follow-up treatments, and subsequent testing on these reference points. However, they may not be aware of inherent limitations related to the definition and derivation of reference intervals. Laboratorians are responsible for providing the reference intervals they report with results. Yet, the establishment and verification of reference intervals using conventional direct methods are complicated by resource constraints or unique patient demographics. To facilitate standardized reference interval best practices, multiple global scientific societies are actively drafting guidelines and seeking funding to promote these initiatives. Numerous national and international multicenter collaborations demonstrate the ability to leverage combined resources to conduct large reference interval studies by direct methods. However, not all demographics are equally accessible. Novel indirect methods are attractive solutions that utilize computational methods to define reference distributions and reference intervals from mixed data sets of pathologic and non-pathologic patient test results. In an effort to make reference intervals more accurate and personalized, individual-based reference intervals are shown to be more useful than population-based reference intervals in detecting clinically significant analyte changes in a patient that might otherwise go unrecognized when using wider, population-based reference intervals. Additionally, continuous reference intervals can provide more accurate ranges as compared to age-based partitions for individuals that are near the ends of the age partition. The advantages and disadvantages of different reference interval approaches as well as the advancement of non-conventional reference interval studies are discussed in this review.
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Affiliation(s)
- Kelly Doyle
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Dustin R Bunch
- Nationwide Children's Hospital & College of Medicine, The Ohio State University, Columbus, OH, USA
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Ma S, Yu J, Qin X, Liu J. Current status and challenges in establishing reference intervals based on real-world data. Crit Rev Clin Lab Sci 2023; 60:427-441. [PMID: 37038925 DOI: 10.1080/10408363.2023.2195496] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 01/29/2023] [Accepted: 03/22/2023] [Indexed: 04/12/2023]
Abstract
Reference intervals (RIs) are the cornerstone for evaluation of test results in clinical practice and are invaluable in judging patient health and making clinical decisions. Establishing RIs based on clinical laboratory data is a branch of real-world data mining research. Compared to the traditional direct method, this indirect approach is highly practical, widely applicable, and low-cost. Improving the accuracy of RIs requires not only the collection of sufficient data and the use of correct statistical methods, but also proper stratification of heterogeneous subpopulations. This includes the establishment of age-specific RIs and taking into account other characteristics of reference individuals. Although there are many studies on establishing RIs by indirect methods, it is still very difficult for laboratories to select appropriate statistical methods due to the lack of formal guidelines. This review describes the application of real-world data and an approach for establishing indirect reference intervals (iRIs). We summarize the processes for establishing iRIs using real-world data and analyze the principle and applicable scope of the indirect method model in detail. Moreover, we compare different methods for constructing growth curves to establish age-specific RIs, in hopes of providing laboratories with a reference for establishing specific iRIs and giving new insight into clinical laboratory RI research. (201 words).
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Affiliation(s)
- Sijia Ma
- Department of Laboratory Medicine, Shengjing Hospital of China Medical University, Liaoning Clinical Research Center for Laboratory Medicine, Shenyang, P.R. China
| | - Juntong Yu
- Department of Laboratory Medicine, Shengjing Hospital of China Medical University, Liaoning Clinical Research Center for Laboratory Medicine, Shenyang, P.R. China
| | - Xiaosong Qin
- Department of Laboratory Medicine, Shengjing Hospital of China Medical University, Liaoning Clinical Research Center for Laboratory Medicine, Shenyang, P.R. China
| | - Jianhua Liu
- Department of Laboratory Medicine, Shengjing Hospital of China Medical University, Liaoning Clinical Research Center for Laboratory Medicine, Shenyang, P.R. China
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Agaravatt A, Kansara G, Khubchandani A, Sanghani H, Patel S, Parchwani D. Verification of Reference Interval of Thyroid Hormones With Manual and Automated Indirect Approaches: Comparison of Hoffman, KOSMIC and refineR Methods. Cureus 2023; 15:e39066. [PMID: 37323364 PMCID: PMC10267605 DOI: 10.7759/cureus.39066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/14/2023] [Indexed: 06/17/2023] Open
Abstract
INTRODUCTION The interpretation of quantitative test results requires the availability of appropriate reference intervals (RIs). Every laboratory has been advised by scientific literature and reagent manufacturers to establish RIs for all analytes. Measuring RIs using direct methods is very costly, and it poses ethical and practical challenges. To overcome these challenges, indirect methods, such as Hoffman, and newer automated approaches, such as KOSMIC and refineR, are used to verify RIs for thyroid hormones. OBJECTIVE To verify RIs for thyroid hormones in adult patients using Hoffman, KOSMIC and refineR methods and to compare these with reference ranges given in kit literature or standard textbooks. MATERIALS AND METHODS The observed values (results) of thyroid hormone were collected from the LIS (Laboratory Information System) of the Biochemistry Department at the B. J. Medical College and Civil Hospital in Ahmedabad between 1 January 2021 and 31 May 2022. Hoffman, KOSMIC and refineR methods were used to verify the RIs. The computerised Hoffman approach, which Katayev et al. describe, is a simple method for determining RI from hospital data. Zierk et al. pre-validated and suggested the KOSMIC method based on Python programming, whereas refineR was proposed by Tatjana et al. based on R programming language. RESULTS Hoffman, KOSMIC and refineR's indirect RI techniques revealed comparable results with kit literature in free T3 and T4, whereas higher upper reference limits of thyroid-stimulating hormone (TSH) compared to kit literature were observed with KOSMIC and refineR methods. However, the computerised Hoffman method revealed comparable results with TSH also. CONCLUSION Indirect approaches, such as Hoffman, KOSMIC and refineR, provide reliable RI verification for free T3 and T4 utilising patient samples obtained from LIS. However, the manual Hoffman method provides reliable RI verification for TSH data derived from the hospital population as compared to automated approaches, such as KOSMIC and refineR.
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Affiliation(s)
- Ashishkumar Agaravatt
- Department of Biochemistry, PDU (Pandit Deendayal Upadhyay) Medical College, Rajkot, IND
| | - Gaurav Kansara
- Department of Biochemistry, Dr. Kiran C. Patel Medical College and Research Institute, Bharuch, IND
| | - Asha Khubchandani
- Department of Biochemistry, BJ (Byramjee Jeejeebhoy) Medical College, Ahmedabad, IND
| | - Hiren Sanghani
- Department of Biochemistry, GMERS (Gujarat Medical Education & Research Society) Medical College, Morbi, IND
| | - Shailesh Patel
- Department of Biochemistry, Government Medical College, Surat, IND
| | - Deepak Parchwani
- Department of Biochemistry, All India Institute of Medical Sciences, Rajkot, IND
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Ghazizadeh H, Kathryn Bohn M, Esmaily H, Boskabadi M, Mohammadi-Bajgiran M, Farahani E, Boshtam M, Mohammadifard N, Sarrafzadegan N, Adeli K, Ghayour-Mobarhan M. Comparison of reference intervals for biochemical and hematology markers derived by direct and indirect procedures based on the Isfahan cohort study. Clin Biochem 2023; 116:79-86. [PMID: 37030657 DOI: 10.1016/j.clinbiochem.2023.04.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 04/03/2023] [Accepted: 04/04/2023] [Indexed: 04/10/2023]
Abstract
INTRODUCTION Indirect methods for reference interval (RI) establishment apply statistical techniques to generate RIs for test result interpretation using stored laboratory data. They present unique advantages relative to traditional direct approaches such as fewer resource requirements; however, there is debate regarding their performance. Herein, we aimed to compare indirect and direct approaches for RI establishment by harnessing data from the Isfahan Cohort Study (ICS). This cohort includes both healthy individuals and those with a history of disease, enabling a direct comparison. METHODS Participants were recruited as part of ICS, including 6504 adults aged 34 years and older. Sociodemographic characteristics, anthropometry, blood pressure, various biochemical indices, and hematology parameters were collected. The refineR method was used to establish indirect RIs (before applying exclusion criteria). Direct RIs were calculated using nonparametric methods per CLSI EP28-A3 guidelines (after applying exclusion criteria). Bias ratios were calculated for each parameter to assess significant differences in estimations. RESULTS Direct and indirect RI estimations for most hematological and biochemical parameters were comparable. Statistically significant bias ratios between methods were observed for the upper limits of total cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL-C), hemoglobin (female), and platelet count as well as the lower limits of mean corpuscular hemoglobin (female), mean corpuscular volume, hemoglobin, and hematocrit (female). CONCLUSION Data presented indicate RIs derived from direct and indirect approaches are similar, but not identical. Further work should focus on the clinical significance of such differences as well as the investigation of necessary data-cleaning criteria before indirect method application.
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Affiliation(s)
- Hamideh Ghazizadeh
- CALIPER Program, Division of Clinical Biochemistry, Pediatric Laboratory Medicine, The Hospital for Sick Children, Toronto, ON, Canada; International UNESCO Center for Health-Related Basic Sciences and Human Nutrition, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mary Kathryn Bohn
- CALIPER Program, Division of Clinical Biochemistry, Pediatric Laboratory Medicine, The Hospital for Sick Children, Toronto, ON, Canada; Department of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Habibollah Esmaily
- Social Determinants of Health Research Center, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Biostatistics, School of Health, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mostafa Boskabadi
- Department of Biostatistics, School of Health, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Maryam Mohammadi-Bajgiran
- International UNESCO Center for Health-Related Basic Sciences and Human Nutrition, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Elina Farahani
- CALIPER Program, Division of Clinical Biochemistry, Pediatric Laboratory Medicine, The Hospital for Sick Children, Toronto, ON, Canada; Department of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Maryam Boshtam
- Heart Failure Research Center, Cardiovascular Research Institute, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Noushin Mohammadifard
- Interventional Cardiology Research Center, Cardiovascular Research Institute, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Nizal Sarrafzadegan
- Isfahan Cardiovascular Research Center, Cardiovascular Research Institute, Isfahan University of Medical Sciences, Isfahan, Iran.
| | - Khosrow Adeli
- CALIPER Program, Division of Clinical Biochemistry, Pediatric Laboratory Medicine, The Hospital for Sick Children, Toronto, ON, Canada; Department of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, ON, Canada.
| | - Majid Ghayour-Mobarhan
- International UNESCO Center for Health-Related Basic Sciences and Human Nutrition, Mashhad University of Medical Sciences, Mashhad, Iran.
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Haeckel R, Adeli K, Jones G, Sikaris K, Wosniok W. Definitions and major prerequisites of direct and indirect approaches for estimating reference limits. Clin Chem Lab Med 2023; 61:402-406. [PMID: 36457149 DOI: 10.1515/cclm-2022-1061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 11/23/2022] [Indexed: 12/04/2022]
Abstract
Reference intervals are established either by direct or indirect approaches. Whereas the definition of direct is well established, the definition of indirect is still a matter of debate. In this paper, a general definition that covers all indirect models presently in use is proposed. With the upcoming popularity of indirect models, it has become evident that further partitioning strategies are required to minimize the risk of patients' false classifications. With indirect methods, such partitions are much easier to execute than with direct methods. The authors believe that the future of reference interval estimation belongs to indirect models with big data pools either from one laboratory or combined from several regional centres (if necessary). Independent of the approach applied, the quality assurance of the pre-analytical and analytical phase, considering biological variables and other confounding factors, is essential.
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Affiliation(s)
- Rainer Haeckel
- Bremer Zentrum für Laboratoriumsmedizin, Klinikum Bremen Mitte, Bremen, Germany
| | - Khosrow Adeli
- Department of Pediatric Laboratory Medicine, The Hospital for Sick Children, Temerty Faculty of Medicine and University of Toronto, Toronto, ON, Canada
| | - Graham Jones
- SydPath, St Vincent's Hospital, Sydney, NSW, Australia.,Faculty of Medicine, University of NSW, Kensington, Australia
| | | | - Werner Wosniok
- Institut für Statistik, Universität Bremen, Bremen, Germany
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Haeckel R, Ammer T, Wosniok W, Krebs A, Torge A, Özcürümez M, Bertram A. Age-and sex-specific reference intervals of total cholesterol, LDL cholesterol, HDL cholesterol and non-HDL cholesterol. Comparison of two algorithms for the indirect estimation of reference intervals. J LAB MED 2023. [DOI: 10.1515/labmed-2022-0147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023] Open
Abstract
Abstract
Objectives
Reference intervals of total cholesterol concentrations in plasma and of their fractions low-density lipoprotein (LDL)-, high-density lipoprotein (HDL)-and non-HDL concentrations are seldom studied with respect to the relevance of age and sex. Therefore, the effect of age and sex on the reference intervals was reinvestigated with 2 indirect procedures.
Methods
As an indirect approach, the truncated minimum chi-square method was applied. All analyses were performed by computer programs available. The script published on the homepage of the German Society of Clinical Chemistry and Laboratory Medicine (DGKL) allows to derive a continuous age dependency of reference intervals together with their confidence and equivalence limits. The results of this approach were compared with those obtained by an indirect method developed more recently, the refineR algorithm.
Results
In the present study, the upper reference limits of total cholesterol varied from 5.1 to 7.8 mmol/L (197–302 mg/dL) depending on various biological variables (as age, sex, inpatients versus outpatients). These upper limits increased with age. Differences between sexes can be neglected except for the age above 80 years. The pattern of reference limits of LDL cholesterol and non-HDL cholesterol paralleled those of total cholesterol. The reference limits of HDL cholesterol were higher in women than in men but were independent of age.
Conclusions
Reference limits for the concentrations of total cholesterol and their fractions LDL-, HDL-and non-HDL concentrations should be stratified for age and sex.
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Affiliation(s)
- Rainer Haeckel
- Bremer Zentrum für Laboratoriumsmedizin, Klinikum Bremen Mitte , Bremen , Germany
| | - Tatjana Ammer
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Chair of Medical Informatics , Erlangen , Germany
- Roche Diagnostics GmbH , Penzberg , Germany
| | - Werner Wosniok
- Institut für Statistik, Universität Bremen , Bremen , Germany
| | | | - Antje Torge
- Institut für Klinische Chemie, Universitätsklinikum Schleswig-Holstein , Kiel , Germany
| | - Mustafa Özcürümez
- Universitätsklinikum Knappschaftskrankenhaus Bochum, Sektion Labormedizin der Medizinischen Klinik , Bochum , Germany
| | - Alexander Bertram
- Amedes MVZ wagnerstibbe für Laboratoriumsmedizin, Hämostaseologie, Humangenetik und Mikrobiologie , Hannover , Germany
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12
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Martinez-Sanchez L, Gabriel-Medina P, Villena-Ortiz Y, García-Fernández AE, Blanco-Grau A, Cobbaert CM, Bravo-Nieto D, Garriga-Edo S, Sanz-Gea C, Gonzalez-Silva G, López-Hellín J, Ferrer-Costa R, Casis E, Rodríguez-Frías F, den Elzen WPJ. Harmonization of indirect reference intervals calculation by the Bhattacharya method. Clin Chem Lab Med 2023; 61:266-274. [PMID: 36395007 DOI: 10.1515/cclm-2022-0439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 11/03/2022] [Indexed: 11/18/2022]
Abstract
OBJECTIVES The aim of this study was to harmonize the criteria for the Bhattacharya indirect method Microsoft Excel Spreadsheet for reference intervals calculation to reduce between-user variability and use these criteria to calculate and evaluate reference intervals for eight analytes in two different years. METHODS Anonymized laboratory test results from outpatients were extracted from January 1st 2018 to December 31st 2019. To assure data quality, we examined the monthly results from an external quality control program. Reference intervals were determined by the Bhattacharya method with the St Vincent's hospital Spreadsheet firstly using original criteria and then using additional harmonized criteria defined in this study. Consensus reference intervals using the additional harmonized criteria were calculated as the mean of four users' lower and upper reference interval results. To further test the operation criteria and robustness of the obtained reference intervals, an external user validated the Spreadsheet procedure. RESULTS The extracted test results for all selected laboratory tests fulfilled the quality criteria and were included in the present study. Differences between users in calculated reference intervals were frequent when using the Spreadsheet. Therefore, additional criteria for the Spreadsheet were proposed and applied by independent users, such as: to set central bin as the mean of all the data, bin size as small as possible, at least three consecutive bins and a high proportion of bins within the curve. CONCLUSIONS The proposed criteria contributed to the harmonization of reference interval calculation between users of the Bhattacharya indirect method Spreadsheet.
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Affiliation(s)
- Luisa Martinez-Sanchez
- Biochemistry Department, Clinical Laboratories, Vall d'Hebron University Hospital, Barcelona, Spain
- Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, Spain
- Department of Clinical Chemistry and Laboratory Medicine, Leiden University Medical Centre, Leiden, The Netherlands
- Clinical Biochemistry Research Team, Vall d'Hebron Institute of Research (VHIR), Barcelona, Spain
| | - Pablo Gabriel-Medina
- Biochemistry Department, Clinical Laboratories, Vall d'Hebron University Hospital, Barcelona, Spain
- Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, Spain
- Clinical Biochemistry Research Team, Vall d'Hebron Institute of Research (VHIR), Barcelona, Spain
| | - Yolanda Villena-Ortiz
- Biochemistry Department, Clinical Laboratories, Vall d'Hebron University Hospital, Barcelona, Spain
- Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, Spain
- Clinical Biochemistry Research Team, Vall d'Hebron Institute of Research (VHIR), Barcelona, Spain
| | - Alba E García-Fernández
- Biochemistry Department, Clinical Laboratories, Vall d'Hebron University Hospital, Barcelona, Spain
- Clinical Biochemistry Research Team, Vall d'Hebron Institute of Research (VHIR), Barcelona, Spain
| | - Albert Blanco-Grau
- Biochemistry Department, Clinical Laboratories, Vall d'Hebron University Hospital, Barcelona, Spain
- Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, Spain
- Clinical Biochemistry Research Team, Vall d'Hebron Institute of Research (VHIR), Barcelona, Spain
| | - Christa M Cobbaert
- Department of Clinical Chemistry and Laboratory Medicine, Leiden University Medical Centre, Leiden, The Netherlands
| | - Daniel Bravo-Nieto
- Biochemistry Department, Clinical Laboratories, Vall d'Hebron University Hospital, Barcelona, Spain
- Clinical Biochemistry Research Team, Vall d'Hebron Institute of Research (VHIR), Barcelona, Spain
| | - Sarai Garriga-Edo
- Biochemistry Department, Clinical Laboratories, Vall d'Hebron University Hospital, Barcelona, Spain
- Clinical Biochemistry Research Team, Vall d'Hebron Institute of Research (VHIR), Barcelona, Spain
| | - Clara Sanz-Gea
- Biochemistry Department, Clinical Laboratories, Vall d'Hebron University Hospital, Barcelona, Spain
- Clinical Biochemistry Research Team, Vall d'Hebron Institute of Research (VHIR), Barcelona, Spain
| | - Gonzalo Gonzalez-Silva
- Biochemistry Department, Clinical Laboratories, Vall d'Hebron University Hospital, Barcelona, Spain
- Clinical Biochemistry Research Team, Vall d'Hebron Institute of Research (VHIR), Barcelona, Spain
| | - Joan López-Hellín
- Biochemistry Department, Clinical Laboratories, Vall d'Hebron University Hospital, Barcelona, Spain
- Clinical Biochemistry Research Team, Vall d'Hebron Institute of Research (VHIR), Barcelona, Spain
| | - Roser Ferrer-Costa
- Biochemistry Department, Clinical Laboratories, Vall d'Hebron University Hospital, Barcelona, Spain
- Clinical Biochemistry Research Team, Vall d'Hebron Institute of Research (VHIR), Barcelona, Spain
| | - Ernesto Casis
- Clinical Laboratories, Vall d'Hebron University Hospital, Barcelona, Spain
| | - Francisco Rodríguez-Frías
- Biochemistry Department, Clinical Laboratories, Vall d'Hebron University Hospital, Barcelona, Spain
- Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, Spain
- Clinical Biochemistry Research Team, Vall d'Hebron Institute of Research (VHIR), Barcelona, Spain
| | - Wendy P J den Elzen
- Clinical Biochemistry Research Team, Vall d'Hebron Institute of Research (VHIR), Barcelona, Spain
- Department of Clinical Chemistry, Amsterdam UMC, University of Amsterdam, Amsterdam Public Health Research Institute, Amsterdam, The Netherlands
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13
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Müller J, Büchsel M, Timme M, App U, Miesbach W, Sachs UJ, Krause M, Scholz U. Reference Intervals in Coagulation Analysis. Hamostaseologie 2022; 42:381-389. [PMID: 36549290 DOI: 10.1055/a-1945-9490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Blood coagulation analysis is characterized by the application of a variety of materials, reagents, and analyzers for the determination of the same parameter, or analyte, by different laboratories worldwide. Accordingly, the application of common reference intervals, that, by definition, would represent a "range of values (of a certain analyte) that is deemed normal for a physiological measurement in healthy persons," is difficult to implement without harmonization of procedures. In fact, assay-specific reference intervals are usually established to allow for the discrimination of normal and abnormal values during evaluation of patient results. While such assay-specific reference intervals are often determined by assay manufacturers and subsequently adopted by customer laboratories, verification of transferred values is still mandatory to confirm applicability on site. The same is true for reference intervals that have been adopted from other laboratories, published information, or determined by indirect data mining approaches. In case transferable reference intervals are not available for a specific assay, a direct recruiting approach may or needs to be applied. In comparison to transferred reference interval verification, however, the direct recruiting approach requires a significantly higher number of well-defined samples to be collected and analyzed. In the present review, we aim to give an overview on the above-mentioned aspects and procedures, also with respect to relevant standards, regulations, guidelines, but also challenges for both, assay manufacturers and coagulation laboratories.
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Affiliation(s)
- Jens Müller
- Institute of Experimental Hematology and Transfusion Medicine, University Hospital Bonn, Bonn, Germany
| | - Martin Büchsel
- Institute of Clinical Chemistry and Laboratory Medicine, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Michael Timme
- Siemens Healthcare Diagnostics Products GmbH, Marburg, Germany
| | - Urban App
- Siemens Healthcare GmbH, Eschborn, Germany
| | - Wolfgang Miesbach
- Medical Clinic 2, Institute of Transfusion Medicine, University Hospital Frankfurt, Frankfurt, Germany
| | - Ulrich J Sachs
- Department of Thrombosis and Hemostasis, Giessen University Hospital, Giessen, Germany.,Institute for Clinical Immunology and Transfusion Medicine, Justus Liebig University, Giessen, Germany
| | - Michael Krause
- Center of Hemostasis, MVZ Labor Dr. Reising-Ackermann und Kollegen, Leipzig, Germany
| | - Ute Scholz
- Center of Hemostasis, MVZ Labor Dr. Reising-Ackermann und Kollegen, Leipzig, Germany
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14
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Ammer T, Schützenmeister A, Prokosch HU, Zierk J, Rank CM, Rauh M. RIbench: A Proposed Benchmark for the Standardized Evaluation of Indirect Methods for Reference Interval Estimation. Clin Chem 2022; 68:1410-1424. [PMID: 36264679 DOI: 10.1093/clinchem/hvac142] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 07/12/2022] [Indexed: 11/14/2022]
Abstract
BACKGROUND Indirect methods leverage real-world data for the estimation of reference intervals. These constitute an active field of research, and several methods have been developed recently. So far, no standardized tool for evaluation and comparison of indirect methods exists. METHODS We provide RIbench, a benchmarking suite for quantitative evaluation of any existing or novel indirect method. The benchmark contains simulated test sets for 10 biomarkers mimicking routine measurements of a mixed distribution of non-pathological (reference) values and pathological values. The non-pathological distributions represent 4 common distribution types: normal, skewed, heavily skewed, and skewed-and-shifted. To identify strengths and weaknesses of indirect methods, test sets have varying sample sizes and pathological distributions differ in location, extent of overlap, and fraction. For performance evaluation, we use an overall benchmark score and sub-scores derived from absolute z-score deviations between estimated and true reference limits. We illustrate the application of RIbench by evaluating and comparing the Hoffmann method and 4 modern indirect methods -TML (Truncated-Maximum-Likelihood), kosmic, TMC (Truncated-Minimum-Chi-Square), and refineR- against one another and against a nonparametric direct method (n = 120). RESULTS For the modern indirect methods, pathological fraction and sample size had a strong influence on the results: With a pathological fraction up to 20% and a minimum sample size of 5000, most methods achieved results comparable or superior to the direct method. CONCLUSIONS We present RIbench, an open-source R-package, for the systematic evaluation of existing and novel indirect methods. RIbench can serve as a tool for enhancement of indirect methods, improving the estimation of reference intervals.
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Affiliation(s)
- Tatjana Ammer
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Chair of Medical Informatics, Erlangen, Germany.,Roche Diagnostics GmbH, Biostatistics & Data Science, Penzberg, Germany
| | | | - Hans-Ulrich Prokosch
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Chair of Medical Informatics, Erlangen, Germany
| | - Jakob Zierk
- Universitätsklinikum Erlangen, Department of Pediatrics and Adolescent Medicine, Erlangen, Germany.,Universitätsklinikum Erlangen, Center of Medical Information and Communication Technology, Erlangen, Germany
| | | | - Manfred Rauh
- Universitätsklinikum Erlangen, Department of Pediatrics and Adolescent Medicine, Erlangen, Germany
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15
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Kim T, Choi H, Lee SM. Parametric and non-parametric estimation of reference intervals for routine laboratory tests: an analysis of health check-up data for 260 889 young men in the South Korean military. BMJ Open 2022; 12:e062617. [PMID: 35879016 PMCID: PMC9328105 DOI: 10.1136/bmjopen-2022-062617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 07/04/2022] [Indexed: 11/03/2022] Open
Abstract
OBJECTIVES Determination of reference intervals (RIs) using big data faces several obstacles due to heterogeneity in analysers, period and ethnicity. The present study aimed to establish the RIs for routine common blood count (CBC) and biochemistry laboratory tests in homogeneous, healthy, male Korean soldiers in their 20s using a large health check-up data set, comparing parametric and non-parametric estimation. DESIGN A multicentre, cross-sectional study. SETTING Seven armed forces hospitals in South Korea. PARTICIPANTS A total of 609 649 men underwent health examination when promoted to corporal between January 2015 and September 2021. 260 889 eligible individuals aged 20-25 were included in the analysis. MAIN OUTCOMES AND MEASURES The RIs were established by parametric and non-parametric methods. In the parametric approach, maximum likelihood estimation was applied to measure the Box-Cox transformation parameter and the values at the 2.5th and 97.5th percentiles were recalculated. The non-parametric approach adopted the Tukey's exclusion test and the values at the 2.5th and 97.5th percentiles were obtained. Classification by body mass index was also performed. RESULTS The obtained RIs for haematology parameters were comparable between devices. If the values followed a Gaussian distribution, parametric and non-parametric methods were well matched for haematology and biochemical markers. When the values were right-skewed, the upper limits were higher with parametric than with non-parametric methods. Participants with obesity showed higher RIs for CBC, some liver function tests and some lipid profiles than participants without obesity. CONCLUSIONS Using data from healthy, male Korean soldiers in their 20s, we proposed the RIs for CBC and biochemical parameters, comparing parametric and non-parametric estimation. As such approaches based on large data sets become more prevalent, further studies are needed to discriminate eligible individuals and determine RIs in an extrapolated sample.
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Affiliation(s)
- Taeyun Kim
- Internal Medicine, The Armed Forces Goyang Hospital, Goyang, Republic of Korea
| | - Hyunji Choi
- Laboratory Medicine, Pusan National University Yangsan Hospital, Yangsan, Republic of Korea
- Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Gyeongnam, Republic of Korea
| | - Sun Min Lee
- Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Gyeongnam, Republic of Korea
- Laboratory Medicine, Pusan National University School of Medicine, Busan, Republic of Korea
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16
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Martinez-Sanchez L, Cobbaert CM, Noordam R, Brouwer N, Blanco-Grau A, Villena-Ortiz Y, Thelen M, Ferrer-Costa R, Casis E, Rodríguez-Frias F, den Elzen WPJ. Indirect determination of biochemistry reference intervals using outpatient data. PLoS One 2022; 17:e0268522. [PMID: 35588100 PMCID: PMC9119462 DOI: 10.1371/journal.pone.0268522] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 05/02/2022] [Indexed: 12/22/2022] Open
Abstract
The aim of this study was to determine reference intervals in an outpatient population from Vall d'Hebron laboratory using an indirect approach previously described in a Dutch population (NUMBER project). We used anonymized test results from individuals visiting general practitioners and analysed during 2018. Analytical quality was assured by EQA performance, daily average monitoring and by assessing longitudinal accuracy between 2018 and 2020 (using trueness verifiers from Dutch EQA). Per test, outliers by biochemically related tests were excluded, data were transformed to a normal distribution (if necessary) and means and standard deviations were calculated, stratified by age and sex. In addition, the reference limit estimator method was also used to calculate reference intervals using the same dataset. Finally, for standardized tests reference intervals obtained were compared with the published NUMBER results. Reference intervals were calculated using data from 509,408 clinical requests. For biochemical tests following a normal distribution, similar reference intervals were found between Vall d'Hebron and the Dutch study. For creatinine and urea, reference intervals increased with age in both populations. The upper limits of Gamma-glutamyl transferase were markedly higher in the Dutch study compared to Vall d'Hebron results. Creatine kinase and uric acid reference intervals were higher in both populations compared to conventional reference intervals. Medical test results following a normal distribution showed comparable and consistent reference intervals between studies. Therefore a simple indirect method is a feasible and cost-efficient approach for calculating reference intervals. Yet, for generating standardized calculated reference intervals that are traceable to higher order materials and methods, efforts should also focus on test standardization and bias assessment using commutable trueness verifiers.
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Affiliation(s)
- Luisa Martinez-Sanchez
- Clinical Laboratories, Biochemistry Department, Vall d’Hebron University Hospital, Barcelona, Spain
- Department of Clinical Chemistry and Laboratory Medicine, Leiden University Medical Centre, Leiden, The Netherlands
- Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Christa M. Cobbaert
- Department of Clinical Chemistry and Laboratory Medicine, Leiden University Medical Centre, Leiden, The Netherlands
| | - Raymond Noordam
- Department of Internal Medicine, Section of Gerontology and Geriatrics, Leiden University Medical Center, Leiden, The Netherlands
| | - Nannette Brouwer
- Diagnost-IQ, Expert Centre for Clinical Chemistry, Purmerend, The Netherlands
| | - Albert Blanco-Grau
- Clinical Laboratories, Biochemistry Department, Vall d’Hebron University Hospital, Barcelona, Spain
| | - Yolanda Villena-Ortiz
- Clinical Laboratories, Biochemistry Department, Vall d’Hebron University Hospital, Barcelona, Spain
- Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Marc Thelen
- Laboratory for Clinical Chemistry and Hematology, Amphia, Breda, The Netherlands
- Stichting Kwaliteitsbewaking Medische Laboratoriumdiagnostiek, Nijmegen, The Netherlands
- Department of Laboratory Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Roser Ferrer-Costa
- Clinical Laboratories, Biochemistry Department, Vall d’Hebron University Hospital, Barcelona, Spain
| | - Ernesto Casis
- Clinical Laboratories, Biochemistry Department, Vall d’Hebron University Hospital, Barcelona, Spain
| | - Francisco Rodríguez-Frias
- Clinical Laboratories, Biochemistry Department, Vall d’Hebron University Hospital, Barcelona, Spain
- Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Wendy P. J. den Elzen
- Clinical Laboratories, Biochemistry Department, Vall d’Hebron University Hospital, Barcelona, Spain
- Department of Clinical Chemistry and Laboratory Medicine, Leiden University Medical Centre, Leiden, The Netherlands
- Atalmedial Diagnostics Centre, Amsterdam, The Netherlands
- Department of Clinical Chemistry, Amsterdam Public Health research institute, Amsterdam UMC, Amsterdam, The Netherlands
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17
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Tan RZ, Markus C, Vasikaran S, Loh TP. Comparison of 8 methods for univariate statistical exclusion of pathological subpopulations for indirect reference intervals and biological variation studies. Clin Biochem 2022; 103:16-24. [PMID: 35181292 DOI: 10.1016/j.clinbiochem.2022.02.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Revised: 01/22/2022] [Accepted: 02/11/2022] [Indexed: 01/06/2023]
Abstract
BACKGROUND Indirect reference intervals and biological variation studies heavily rely on statistical methods to separate pathological and non-pathological subpopulations within the same dataset. In recognition of this, we compare the performance of eight univariate statistical methods for identification and exclusion of values originating from pathological subpopulations. METHODS The eight approaches examined were: Tukey's rule with and without Box-Cox transformation; median absolute deviation; double median absolute deviation; Gaussian mixture models; van der Loo (Vdl) methods 1 and 2; and the Kosmic approach. Using four scenarios including lognormal distributions and varying the conditions through the number of pathological populations, central location, spread and proportion for a total of 256 simulated mixed populations. A performance criterion of ±0.05 fractional error from the true underlying lower and upper reference interval was chosen. RESULTS Overall, the Kosmic method was a standout with the highest number of scenarios lying within the acceptable error, followed by Vdl method 1 and Tukey's rule. Kosmic and Vdl method 1 appears to discriminate better the non-pathological reference population in the case of log-normal distributed data. When the proportion and spread of pathological subpopulations is high, the performance of statistical exclusion deteriorated considerably. DISCUSSIONS It is important that laboratories use a priori defined clinical criteria to minimise the proportion of pathological subpopulation in a dataset prior to analysis. The curated dataset should then be carefully examined so that the appropriate statistical method can be applied.
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Affiliation(s)
- Rui Zhen Tan
- Engineering Cluster, Singapore Institute of Technology, Singapore
| | - Corey Markus
- International Centre for Point-of-Care Testing, Flinders Health and Medical Research Institute, Flinders University
| | - Samuel Vasikaran
- Department of Clinical Biochemistry, PathWest-Royal Perth Hospital, Perth, Western Australia, Australia
| | - Tze Ping Loh
- Department of Laboratory Medicine, National University Hospital, Singapore.
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18
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Yang D, Su Z, Zhao M. Big data and reference intervals. Clin Chim Acta 2022; 527:23-32. [PMID: 34999059 DOI: 10.1016/j.cca.2022.01.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 12/29/2021] [Accepted: 01/03/2022] [Indexed: 12/12/2022]
Abstract
Although reference intervals (RIs) play an important role in clinical diagnosis, there remain significant differences with respect to race, gender, age and geographic location. Accordingly, the Clinical Laboratory Standards Institute (CLSI) EP28-A3c has recommended that clinical laboratories establish RIs appropriate to their subject population. Unfortunately, the traditional and direct approach to establish RIs relies on the recruitment of a sufficient number of healthy individuals of various age groups, collection and testing of large numbers of specimens and accurate data interpretation. The advent of the big data era has, however, created a unique opportunity to "mine" laboratory information. Unfortunately, this indirect method lacks standardization, consensus support and CLSI guidance. In this review we provide a historical perspective, comprehensively assess data processing and statistical methods, and post-verification analysis to validate this big data approach in establishing laboratory specific RIs.
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Affiliation(s)
- Dan Yang
- National Clinical Research Center for Laboratory Medicine, The First Affiliated Hospital of China Medical University, Shenyang, PR China; Department of Laboratory Medicine, The First Affiliated Hospital of China Medical University, Shenyang, PR China; Units of Medical Laboratory, Chinese Academy of Medical Sciences, PR China
| | - Zihan Su
- National Clinical Research Center for Laboratory Medicine, The First Affiliated Hospital of China Medical University, Shenyang, PR China; Department of Laboratory Medicine, The First Affiliated Hospital of China Medical University, Shenyang, PR China; Units of Medical Laboratory, Chinese Academy of Medical Sciences, PR China
| | - Min Zhao
- National Clinical Research Center for Laboratory Medicine, The First Affiliated Hospital of China Medical University, Shenyang, PR China; Department of Laboratory Medicine, The First Affiliated Hospital of China Medical University, Shenyang, PR China; Units of Medical Laboratory, Chinese Academy of Medical Sciences, PR China.
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19
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Ha F, Wu Y, Wang H, Wang T. The Reference Intervals of Whole Blood Copper, Zinc, Calcium, Magnesium, and Iron in Infants Under 1 Year Old. Biol Trace Elem Res 2022; 200:1-12. [PMID: 33625659 DOI: 10.1007/s12011-021-02620-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 01/31/2021] [Indexed: 10/22/2022]
Abstract
Trace elements are essential nutrients for the optimal growth, development, and health of infants, and the reference intervals (RIs) from these trace elements in the blood are very important for an accurate assessment of the status of the elements. In this study, blood samples from a total of 13,446 infants (7206 boys and 6240 girls) were used, and the copper (Cu), zinc (Zn), calcium (Ca), magnesium (Mg), and iron (Fe) in their blood were determined using atomic absorption spectrometry. After clearing the data and removing any outliers, the gender- and age-specific RIs obtained from the Cu, Zn, Ca, Mg, and Fe in the infants' blood were established according to the principles of the Clinical and Laboratory Standards Institute (CLSI) C28-A3. In the multivariable analysis, after making the relevant adjustments for the confounding factors, the age of the infants showed a significant positive correlation with the concentrations of Zn, Ca, Mg, and Fe found in the blood (p<0.01). Furthermore, there were obvious differences in the Cu, Zn, and Ca levels in the blood according to the gender of the infants (p<0.01). As infants are in the critical period of their growth and development, the gender- and age-specific RIs may provide helpful guidance for the nutritional status of the Cu, Zn, Ca, Mg, and Fe elements in the infants' blood.
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Affiliation(s)
- Feizai Ha
- Department of Clinical Laboratory, Peking University Third Hospital, No. 49, North Garden Road, Haidian District, Beijing, China
| | - Yonghua Wu
- Department of Clinical Laboratory, Peking University Third Hospital, No. 49, North Garden Road, Haidian District, Beijing, China
| | - Haining Wang
- Department of Endocrinology and Metabolism, Peking University Third Hospital, Beijing, China
| | - Tiancheng Wang
- Department of Endocrinology and Metabolism, Peking University Third Hospital, Beijing, China.
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20
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Abstract
Abstract
Laboratory tests are essential to assess the health status and to guide patient care in individuals of all ages. The interpretation of quantitative test results requires availability of appropriate reference intervals, and reference intervals in children have to account for the extensive physiological dynamics with age in many biomarkers. Creation of reference intervals using conventional approaches requires the sampling of healthy individuals, which is opposed by ethical and practical considerations in children, due to the need for a large number of blood samples from healthy children of all ages, including neonates and young infants. This limits the availability and quality of pediatric reference intervals, and ultimately negatively impacts pediatric clinical decision-making. Data mining approaches use laboratory test results and clinical information from hospital information systems to create reference intervals. The extensive number of available test results from laboratory information systems and advanced statistical methods enable the creation of pediatric reference intervals with an unprecedented age-related accuracy for children of all ages. Ongoing developments regarding the availability and standardization of electronic medical records and of indirect statistical methods will further improve the benefit of data mining for pediatric reference intervals.
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Affiliation(s)
- Jakob Zierk
- Department of Pediatrics and Adolescent Medicine , University Hospital Erlangen , Erlangen , Germany
| | - Markus Metzler
- Department of Pediatrics and Adolescent Medicine , University Hospital Erlangen , Erlangen , Germany
| | - Manfred Rauh
- Department of Pediatrics and Adolescent Medicine , University Hospital Erlangen , Erlangen , Germany
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21
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Ammer T, Schützenmeister A, Prokosch HU, Rauh M, Rank CM, Zierk J. refineR: A Novel Algorithm for Reference Interval Estimation from Real-World Data. Sci Rep 2021; 11:16023. [PMID: 34362961 PMCID: PMC8346497 DOI: 10.1038/s41598-021-95301-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 07/21/2021] [Indexed: 01/02/2023] Open
Abstract
Reference intervals are essential for the interpretation of laboratory test results in medicine. We propose a novel indirect approach to estimate reference intervals from real-world data as an alternative to direct methods, which require samples from healthy individuals. The presented refineR algorithm separates the non-pathological distribution from the pathological distribution of observed test results using an inverse approach and identifies the model that best explains the non-pathological distribution. To evaluate its performance, we simulated test results from six common laboratory analytes with a varying location and fraction of pathological test results. Estimated reference intervals were compared to the ground truth, an alternative indirect method (kosmic), and the direct method (N = 120 and N = 400 samples). Overall, refineR achieved the lowest mean percentage error of all methods (2.77%). Analyzing the amount of reference intervals within ± 1 total error deviation from the ground truth, refineR (82.5%) was inferior to the direct method with N = 400 samples (90.1%), but outperformed kosmic (70.8%) and the direct method with N = 120 (67.4%). Additionally, reference intervals estimated from pediatric data were comparable to published direct method studies. In conclusion, the refineR algorithm enables precise estimation of reference intervals from real-world data and represents a viable complement to the direct method.
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Affiliation(s)
- Tatjana Ammer
- Chair of Medical Informatics, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany. .,Roche Diagnostics GmbH, Penzberg, Germany.
| | | | - Hans-Ulrich Prokosch
- Chair of Medical Informatics, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
| | - Manfred Rauh
- Department of Pediatrics and Adolescent Medicine, University Hospital Erlangen, Erlangen, Germany
| | | | - Jakob Zierk
- Department of Pediatrics and Adolescent Medicine, University Hospital Erlangen, Erlangen, Germany.,Center of Medical Information and Communication Technology, University Hospital Erlangen, Erlangen, Germany
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22
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Haeckel R, Wosniok W. The importance of correct stratifications when comparing directly and indirectly estimated reference intervals. Clin Chem Lab Med 2021; 59:cclm-2021-0353. [PMID: 34049430 DOI: 10.1515/cclm-2021-0353] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 05/17/2021] [Indexed: 11/15/2022]
Abstract
OBJECTIVES There are generally two major reasons for the comparison of reference intervals (RIs): when externally determined RIs (from the literature or provided by a manufacturer) are compared with presently used intra-laboratory RIs and when indirectly estimated RIs are compared with directly established RIs. Discrepancies within these comparisons may occur for two reasons: 1. the pre-analytical and/or analytical conditions do not agree and/or 2. biological variables influencing the establishment of RIs have not been considered adequately. If directly and indirectly estimated reference intervals (RIs) are compared with each other, they very often agree. Sometimes, however, a comparison may differ, with the reason for any discrepancy not being further studied. A major reason for differences in the comparison of RIs is that the requirement for stratification has been neglected. METHODS The present report outlines the consequences to RI comparison if stratification is neglected during RI determination with the main variables affecting RIs being sex and age. Alanine aminotransferase was chosen as an example in which the RIs depend on both these factors. RESULTS Both direct and indirect approaches lead to erroneous RIs if stratification for variables which are known to affect the estimation of RIs is not performed adequately. However, failing to include a required stratification in procedures for directly determined RIs affects the outcome in a different way to indirectly determined RIs. CONCLUSIONS The resulting difference between direct and indirect RIs is often misinterpreted as an incorrect RI estimation of the indirect method.
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Affiliation(s)
- Rainer Haeckel
- Bremer Zentrum für Laboratoriumsmedizin, Klinikum Bremen Mitte, 28305Bremen, Germany
| | - Werner Wosniok
- Institut für Statistik, Universität Bremen, Bremen, Germany
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23
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Amodeo B, Schindler A, Schacht U, Wahl HG. Calculation of indirect reference intervals of plasma lipase activity of adults from existing laboratory data based on the Reference Limit Estimator integrated in the OPUS::L information system. J LAB MED 2021. [DOI: 10.1515/labmed-2021-0008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Abstract
Objectives
Most laboratories have difficulties to determine their own reference intervals for the diagnostic evaluation of patient results by direct methods. Therefore, data is often just taken from the literature or package inserts of the analytical tests.
Methods
The section on Reference Limits of the German Society for Clinical Chemistry and Laboratory Medicine (DGKL) first uploaded the Reference Limit Estimator (RLE) as an R-program with MS Excel-interface on the DGKL home page and now this tool is implemented in the commercial Laboratory Information System OPUS::L (OSM AG Essen, Germany). We used this OPUS::L “Population specific Reference Limits” tool online with our laboratory database. First calculations were done using the example of lipase.
Results
The manufacturer’s original reference interval for lipase 12–53 U/L (adults) was changed to age dependent upper reference limits of <41 U/L (<20 years), <60 U/L (20–80 years) and <70 U/L (>80 years).
Conclusions
By means of the OPUS::L “Population specific Reference Limits” tool we were able to establish our laborarotry specific reference interval for plasma lipase activity. The new reference limits helped to solve an old problem of implausible low elevated lipase values.
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Affiliation(s)
| | | | | | - Hans Günther Wahl
- Medizinisches Labor Wahl , Lüdenscheid , Germany
- Institute of Laboratory Medicine and Pathobiochemistry , Philipps University Marburg , UKGM Marburg GmbH , Marburg , Germany
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24
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Haeckel R, Wosniok W, Streichert T. Review of potentials and limitations of indirect approaches for estimating reference limits/intervals of quantitative procedures in laboratory medicine. J LAB MED 2021. [DOI: 10.1515/labmed-2020-0131] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Abstract
Reference intervals (RIs) can be determined by direct and indirect procedures. Both approaches identify a reference population from which the RIs are defined. The crucial difference between direct and indirect methods is that direct methods select particular individuals after individual anamnesis and medical examination have confirmed the absence of pathological conditions. These individuals form a reference subpopulation. Indirect methods select a reference subpopulation in which the individuals are not identified. They isolate a reference population from a mixed population of patients with pathological and non-pathological conditions by statistical reasoning.
At present, the direct procedure internationally recommended is the “gold standard”. It has, however, the disadvantage of high expenses which cannot easily be afforded by most medical laboratories. Therefore, laboratories adopt RIs established by direct methods from external sources requiring a high responsibility for transference problems which are usually neglected by most laboratories. These difficulties can be overcome by indirect procedures which can easily be performed by most laboratories without causing economic problems.
The present review focuses on indirect approaches. Various procedures are presented with their benefits and limitations. Preliminary simulation studies indicate that more recently developed concepts are superior to older approaches.
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Affiliation(s)
- Rainer Haeckel
- Bremer Zentrum für Laboratoriumsmedizin, Klinikum Bremen Mitte , Bremen , Germany
| | - Werner Wosniok
- Institut für Statistik, Universität Bremen , Bremen , Germany
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25
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Abstract
Abstract
The indirect approach to defining reference intervals operates ‘a posteriori’, on stored laboratory data. It relies on being able to separate healthy and diseased populations using one or both of clinical techniques or statistical techniques. These techniques are also fundamental in a priori, direct reference interval approaches. The clinical techniques rely on using clinical data that is stored either in the electronic health record or within the laboratory database, to exclude patients with possible disease. It depends on the investigators understanding of the data and the pathological impacts on tests. The statistical technique relies on identifying a dominant, apparently healthy, typically Gaussian distribution, which is unaffected by the overlapping populations with higher (or lower) results. It depends on having large databases to give confidence in the extrapolation of the narrow portion of overall distribution representing unaffected individuals. The statistical issues involved can be complex, and can result in unintended bias, particularly when the impacts of disease and the physiological variations in the data are under appreciated.
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Affiliation(s)
- Kenneth A. Sikaris
- Department of Biochemistry , Melbourne Pathology , Collingwood , VIC , Australia
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26
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Affiliation(s)
- Rainer Haeckel
- Bremer Zentrum für Laboratoriumsmedizin , Klinikum Bremen Mitte , 28305 Bremen , Germany
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27
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Arzideh F, Özcürümez M, Albers E, Haeckel R, Streichert T. Indirect estimation of reference intervals using first or last results and results from patients without repeated measurements. J LAB MED 2021. [DOI: 10.1515/labmed-2020-0149] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Abstract
Objectives
Indirect methods for the estimation of Reference Limits (RLs) use large data pools stored in modern laboratory information’s systems. To avoid correlation between observations repeated results from each patient should be excluded. Some data pools obtained are anonymized, and thereafter the data cannot be re-identified. The effect of the procedure of data selection on the estimations is not investigated yet.
Methods
We considered four parameters. Data sets were enclosed from two sources: a university hospital and a laboratory primarily reflecting a patient population from medical practitioners. Four algorithms were used for data selection, which generate first, last, all and non-repeated values. RLs were estimated through these data sets and compared.
Results
This study showed the broader reference range estimated by indirect methods if using the whole data set compared to first/last values or non-repeated values.
Conclusions
The use of all data without a filtering step results in a significant bias whereas the choice of first or last values has nearly no impact. The exclusion of repeated measurements results in narrower RLs. This influence confine the use of anonymous data sets where filtering is impossible for the estimation of RLs by indirect methods.
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Affiliation(s)
- Farhad Arzideh
- Institute for Clinical Chemistry, Faculty of Medicine , University of Cologne , Cologne , Germany
- Universitätsklinikum Knappschaftskrankenhaus Bochum GmbH , Bochum , Germany
| | - Mustafa Özcürümez
- Universitätsklinikum Knappschaftskrankenhaus Bochum GmbH , Bochum , Germany
| | - Eike Albers
- Institute for Clinical Chemistry, Faculty of Medicine , University of Cologne , Cologne , Germany
- MVZ Labor Dr. Quade & Kollegen GmbH , Cologne , Germany
| | - Rainer Haeckel
- Bremer Zentrum für Laboratoriumsmedizin, Klinikum Bremen Mitte , Bremen , Germany
| | - Thomas Streichert
- Institute for Clinical Chemistry, Faculty of Medicine , University of Cologne , Cologne , Germany
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28
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Martinez-Sanchez L, Marques-Garcia F, Ozarda Y, Blanco A, Brouwer N, Canalias F, Cobbaert C, Thelen M, den Elzen W. Big data and reference intervals: rationale, current practices, harmonization and standardization prerequisites and future perspectives of indirect determination of reference intervals using routine data. ADVANCES IN LABORATORY MEDICINE 2021; 2:9-25. [PMID: 37359198 PMCID: PMC10197285 DOI: 10.1515/almed-2020-0034] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 06/24/2020] [Indexed: 06/28/2023]
Abstract
Reference intervals are commonly used as a decision-making tool. In this review, we provide an overview on "big data" and reference intervals, describing the rationale, current practices including statistical methods, essential prerequisites concerning data quality, including harmonization and standardization, and future perspectives of the indirect determination of reference intervals using routine laboratory data.
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Affiliation(s)
- Luisa Martinez-Sanchez
- Clinical Biochemistry Department, Vall d’Hebron University Hospital, Barcelona, Spain
- Department of Clinical Chemistry and Laboratory Medicine, Leiden University Medical Centre, Leiden, The Netherlands
- Department de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | | | - Yesim Ozarda
- Department of Medical Biochemistry, Uludag University School of Medicine, Bursa, Turkey
| | - Albert Blanco
- Clinical Biochemistry Department, Vall d’Hebron University Hospital, Barcelona, Spain
| | - Nannette Brouwer
- Diagnost-IQ, Expert Centre for Clinical Chemistry, Purmerend, The Netherlands
| | - Francesca Canalias
- Laboratori de Referència d’Enzimologia Clínica, Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Christa Cobbaert
- Department of Clinical Chemistry and Laboratory Medicine, Leiden University Medical Centre, Leiden, The Netherlands
| | - Marc Thelen
- Laboratory for Clinical Chemistry and Hematology, Amphia, Breda, The Netherlands
- Stichting Kwaliteitsbewaking Medische Laboratoriumdiagnostiek, Nijmegen, The Netherlands
| | - Wendy den Elzen
- Department of Clinical Chemistry and Laboratory Medicine, Leiden University Medical Centre, Leiden, The Netherlands
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29
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Torge A, Haeckel R, Özcürümez M, Krebs A, Junker R. Diurnal variation of leukocyte counts affects the indirect estimation of reference intervals. J LAB MED 2021. [DOI: 10.1515/labmed-2020-0132] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Abstract
It has been observed that the estimation of reference intervals of leukocytes in whole venous blood leads to higher upper reference limits (uRLs) with indirect methods than has been reported in the literature determined by direct approaches. This phenomenon was reinvestigated with a newer, more advanced indirect method, and could be confirmed. Furthermore, a diurnal variation was observed with lower values during the morning and higher values in the late afternoon and at night. This observation can explain why indirect approaches using samples collected during 24 h lead to higher uRLs than direct methods applied on samples collected presumably in the morning.
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Affiliation(s)
- Antje Torge
- Institut für Klinische Chemie , Universitätsklinikum Schleswig-Holstein , Kiel , Germany
| | - Rainer Haeckel
- Bremer Zentrum für Laboratoriumsmedizin , Klinikum Bremen Mitte , Bremen , Germany
| | - Mustafa Özcürümez
- Sektion Labormedizin der Medizinischen Klinik , Universitätsklinikum Knappschaftskrankenhaus Bochum , Bochum , Germany
| | - Alexander Krebs
- MVZ Labor PD Dr. Volkmann und Kollegen , Karlsruhe , Germany
| | - Ralf Junker
- Institut für Klinische Chemie , Universitätsklinikum Schleswig-Holstein , Kiel , Germany
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30
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Reference limits of high-sensitive cardiac troponin T indirectly estimated by a new approach applying data mining. A special example for measurands with a relatively high percentage of values at or below the detection limit. J LAB MED 2020. [DOI: 10.1515/labmed-2020-0063] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Abstract
A new model for the indirect estimation of reference limits (RLs) has been proposed recently and was coined TMC approach (truncated minimum chi-square estimation) which can be performed with R statistic. A spline function is applied to the RLs to get a continuous function if age is graphically presented vs. the RLs avoiding artificial “jumps” between different age groups. Most indirect models assume a power normal distribution and fail if this assumption is not fulfilled as e.g. if a relatively high percentage of measured values is below the detection limit and the data are distributed extremely skewed. This problem is handled by the TMC model. High-sensitive cardiac troponin T (hs cTnT) was chosen as an example. The hs cTnT concentration in serum or plasma is well accepted as a valuable marker in the diagnosis of acute myocardial infarction. Currently, the 99th percentile derived from a “healthy” subpopulation is the decision limit recommended by consensus groups. However, this decision limit is questioned by several authors for many reasons. In the present report, the 97.5th and the 99th percentile limits were reinvestigated by the TMC model with different subpopulations stratified according to age and sex and were finally compared to presently recommended decision limits. In summary, the generally recommended 99th percentile as a fixed decision limit should be reconsidered. It is suggested to apply more specific reference limits stratified for age and sex instead of a fixed decision limit.
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31
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Haeckel R, Wosniok W, Torge A, Junker R, Bertram A, Krebs A, Özcürümez M, Orth M, Streichert T. Age and sex dependent reference intervals for random plasma/serum glucose concentrations related to different sampling devices and determined by an indirect procedure with data mining. J LAB MED 2020. [DOI: 10.1515/labmed-2020-0064] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Abstract
The glucose concentration in plasma or serum is one of the most often requested analytical values in laboratory medicine. Whereas the analytical part of the glucose determination is well standardised, the standardisation of the pre-examination part (pre-analytical phase) is not sufficiently solved, yet. In view of the present controversial discussion regarding the most efficient prevention of pre-analytical glycolysis, the question arises whether the economical and logistic expenses for inhibiting glycolysis determining random glucose concentration are justified. In hospitals with adequate logistics (e.g. pneumatic tube systems for blood tubes) to guarantee a blood sample transport time of about 1 – 2 h, plasma or serum without prevention of glycolysis can be applied for random glucose concentrations if the reference limits are estimated by the laboratory. If such logistics are not available, especially in primary care services, either plasma or serum samples or whole blood in special tubes with anti-glycolytic additives may be sent to the laboratory.
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Affiliation(s)
- Rainer Haeckel
- Bremer Zentrum für Laboratoriumsmedizin, Klinikum Bremen Mitte , 28305 Bremen , Germany
| | - Werner Wosniok
- Institut für Statistik, Universität Bremen , Bremen , Germany
| | - Antje Torge
- Institut für Klinische Chemie, Universitätsklinikum Schleswig-Holstein , Kiel , Germany
| | - Ralf Junker
- Institut für Klinische Chemie, Universitätsklinikum Schleswig-Holstein , Kiel , Germany
| | - Alexander Bertram
- Amedes MVZ wagnerstibbe für Laboratoriumsmedizin, Hämostaseologie, Humangenetik und Mikrobiologie , Hannover , Germany
| | - Alexander Krebs
- MVZ Labor PD Dr. Volkmann und Kollegen , Karlsruhe , Germany
| | - Mustafa Özcürümez
- Universitätsklinikum Knappschaftskrankenhaus Bochum, Sektion Labormedizin der Medizinischen Klinik , Bochum , Germany
| | - Matthias Orth
- Institut für Laboratoriumsmedizin, Vinzenz von Paul Kliniken GmbH , Stuttgart , Germany
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32
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Klawonn F, Hoffmann G, Orth M. Quantitative laboratory results: normal or lognormal distribution? J LAB MED 2020. [DOI: 10.1515/labmed-2020-0005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Abstract
The identification of a suitable distribution model is a prerequisite for the parametric estimation of reference intervals and other statistical laboratory tasks. Classification of normal vs. lognormal distributions from healthy populations is easy, but from mixed populations, containing unknown proportions of abnormal results, it is challenging. We demonstrate that Bowley’s skewness coefficient differentiates between normal and lognormal distributions. This classifier is robust and easy to calculate from the quartiles Q1–Q3 according to the formula (Q1 − 2 · Q2 + Q3)/(Q3 − Q1). We validate our algorithm with a more complex procedure, which optimizes the exponent λ of a power transformation. As a practical application, we show that Bowley’s skewness coefficient is suited selecting the adequate distribution model for the estimation of reference limits according to a recent International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) recommendation, especially if the data is right-skewed.
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Affiliation(s)
- Frank Klawonn
- Helmholtz Centre for Infection Research , Braunschweig , Germany
- Ostfalia University , Wolfenbüttel , Germany
| | - Georg Hoffmann
- German Heart Center , Munich , Germany
- Trillium GmbH Medizinischer Fachverlag , Grafrath , Germany
| | - Matthias Orth
- Vinzenz von Paul Kliniken gGmbH , Stuttgart , Germany
- Medizinische Fakultät Mannheim, Ruprecht Karls Universität , Mannheim , Germany
- Institut für Laboratoriumsmedizin , Adlerstr. 7 , 70199 Stuttgart , Germany
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Haeckel R, Wosniok W, Torge A, Junker R. Age- and sex-dependent reference intervals for uric acid estimated by the truncated minimum chi-square (TMC) approach, a new indirect method. J LAB MED 2020. [DOI: 10.1515/labmed-2019-0164] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Abstract
Background
Although the concentration of uric acid in serum or plasma is known to depend on sex and age and is subject to diurnal variation, the influence of these covariates on the reference interval (RI) is often neglected. Consequently, the values in the literature vary considerably. Therefore, we reinvestigated the reference limits and their dependence on covariates.
Methods
A new indirect approach was applied which derives a continuous function between age and RIs avoiding the usual “jumps” between various age groups.
Results
It is confirmed that the uric acid concentration in women is lower than in men. The RIs increase with age, in women more than in men. Between 80 and 90 years of age, the upper RI limit (RL) approximately reaches the same level in both sexes. Because the uric acid concentration may indicate renal insufficiency, the concentrations of creatinine and cystatin C were also measured. Both measurands showed the same behaviour as uric acid. Therefore, the age and sex dependency should be considered if the uric acid concentration is used as an indicator for hyperuricaemia (e.g. caused by gout or other metabolic diseases). Furthermore, a diurnal variation was observed.
Conclusions
Due to the variations of various covariates (age, sex, daytime, analytical systems), it is recommended that each laboratory should estimate its own RIs.
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Affiliation(s)
- Rainer Haeckel
- Institute for Laboratory Medicine , Katrepeler Landstr. 45E , 28357 Bremen , Germany , Phone: +49 412 273448
| | - Werner Wosniok
- Institut für Statistik , Universität Bremen , Bremen , Germany
| | - Antje Torge
- Institut für Klinische Chemie , Universitätsklinikum Schleswig-Holstein , Kiel , Germany
| | - Ralf Junker
- Institut für Klinische Chemie , Universitätsklinikum Schleswig-Holstein , Kiel , Germany
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