Reference interval studies: what is the maximum number of samples recommended?
-
Robert C. Hawkins
and
Tony Badrick
Abstract
Background: Little attention has been paid to the maximum number of specimens for reference interval calculation, i.e., the number of specimens beyond which there is no further benefit in reference interval calculation. We present a model for the estimation of the maximum number of specimens for reference interval studies based on setting the 90% confidence interval of the reference limits to be equal to the analyte reporting interval.
Methods: Equations describing the bounds on the upper and lower 90% confidence intervals for logarithmically transformed and untransformed data were derived and applied to determine the maximum number of specimens required to calculate a reference interval for 12 common chemistry and hematology analytes.
Results: Maximum sample sizes ranged from 126 to 18,171 and depended on the standard deviation of the population, any transformation involved and on the chosen reporting interval.
Conclusions: This paper demonstrates the importance of the influence of reporting interval on reference intervals. Using this technique can reduce the cost of determining a reference interval by identifying the maximum number of specimens required.
Appendix
We recall the hyperbolic sinh function sinh(x)=0.5[exp(x) –exp(−x)] we can simplify Eq. (14) as follows:
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©2013 by Walter de Gruyter Berlin Boston
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Articles in the same Issue
- Letter to the Editor
- Elevated level of cell-free plasma DNA is associated with advanced-stage breast cancer and metastasis
- Is procalcitonin a reliable marker of sepsis in critically ill septic patients undergoing continuous veno-venous hemodiafiltration with “high cut-off” membranes (HCO-CVVHDF)?
- Challenging our serological algorithm for celiac disease (CD) diagnosis by the ESPGHAN guidelines
- Preanalytical quality control in a university hospital in China
- Racial differences and relationships between gestational thyrotropin and free thyroxine in a multiracial Asian population
- Analytical performance and method comparison study of the total homocysteine immunoassay on the AIA 600II analyser
- Easy verification of clinical chemistry reference intervals
- The Elecsys® Vitamin B12 assay is not affected by anti-intrinsic factor antibodies
- Chemiluminescence-based cobalamin assay errors: background and perspectives
- Congress Abstracts
- Abstracts IV Italian Great Network Congress Rome, 14th–18th October 2013*)
- Masthead
- Masthead
- Editorial
- Making colorectal cancer screening FITTER for purpose with quantitative faecal immunochemical tests for haemoglobin (FIT)
- From “panic” to “critical” values: which path toward harmonization?
- Review
- Cerebrospinal fluid analyses for the diagnosis of subarachnoid haemorrhage and experience from a Swedish study. What method is preferable when diagnosing a subarachnoid haemorrhage?
- Opinion Paper
- False myths and legends in laboratory diagnostics
- General Clinical Chemistry and Laboratory Medicine
- National survey on critical values notification of 599 institutions in China
- Influence of physical properties of cuvette surface on measurement of serum lipase
- Red cell indices: differentiation between β-thalassemia trait and iron deficiency anemia and application to sickle-cell disease and sickle-cell thalassemia
- Measurement of immature platelets with Abbott CD-Sapphire and Sysmex XE-5000 in haematology and oncology patients
- Performance characteristics of consensus approaches for small and minor paroxysmal nocturnal hemoglobinuria clone determination by flow cytometry
- Comparison of PR3-ANCA specific assay performance for the diagnosis of granulomatosis with polyangiitis (Wegener’s)
- The integration of the detection of systemic sclerosis-associated antibodies in a routine laboratory setting: comparison of different strategies
- Reference Values and Biological Variations
- Reference interval studies: what is the maximum number of samples recommended?
- Short-term estimation and application of biological variation of small dense low-density lipoproteins in healthy individuals
- Cancer Diagnostics
- Diagnostic inconsistency of faecal immunochemical tests for haemoglobin in population screening of colorectal cancer
- Cardiovascular Diseases
- Comparison of the 99th percentiles of three troponin I assays in a large reference population
- Assessment of plasma aminothiol levels and the association with recurrent atherothrombotic events in patients hospitalized for an acute coronary syndrome: a prospective study
- Diabetes
- The relationship between estimated average glucose and fasting plasma glucose
- Evaluation of enzymatic BM Test HbA1c on the JCA-BM6010/C and comparison with Bio-Rad Variant II Turbo, Tosoh HLC 723 G8, and AutoLab immunoturbidimetry assay
