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Reference interval studies: what is the maximum number of samples recommended?
Clinical Chemistry and Laboratory Medicine
|June 27, 2013
Summary
Determining the maximum number of specimens for reference interval calculation is crucial. This study presents a model to optimize sample sizes, reducing costs by identifying the point of diminishing returns for reference interval studies.
Area of Science:
- Clinical Chemistry
- Laboratory Medicine
- Biostatistics
Background:
- Reference interval determination is essential for clinical diagnostics.
- Optimal specimen number for reference interval calculation remains underexplored.
- Current methods may involve excessive or insufficient sample sizes.
Purpose of the Study:
- To develop and present a model for estimating the maximum number of specimens needed for reference interval studies.
- To establish a method for determining the point beyond which additional specimens offer no significant benefit.
- To optimize resource allocation in laboratory medicine.
Main Methods:
- Derived equations for confidence interval bounds of reference limits.
- Applied derived equations to transformed and untransformed data.
- Calculated maximum specimen numbers for 12 common analytes.
Main Results:
- Maximum sample sizes varied widely (126 to 18,171 specimens).
- Required sample size depends on population standard deviation and data transformation.
- The chosen analyte reporting interval significantly influences the maximum number of specimens.
Conclusions:
- The reporting interval critically impacts reference interval calculations.
- This model-based approach can significantly reduce the cost of reference interval studies.
- Optimizing specimen numbers enhances efficiency in laboratory diagnostics.
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