Use and abuse of imprecision profiles: some pitfalls illustrated by computing and plotting confidence intervals
1Department of Nuclear Medicine, Christchurch Hospital, New Zealand.
Clinical Chemistry
|July 1, 1990
Summary
Estimating immunoassay imprecision profiles requires robust data. This study introduces a method using 95% confidence intervals to improve the reliability of these crucial diagnostic assay characteristics.
Area of Science:
- Clinical Chemistry
- Laboratory Medicine
- Biostatistics
Background:
- Published imprecision estimates for immunoassays often lack sufficient data.
- Imprecision profiles are increasingly used but may not always improve accuracy.
- Current methods may not adequately represent the uncertainty in assay performance.
Purpose of the Study:
- To present a method for calculating 95% confidence intervals for immunoassay imprecision profiles.
- To illustrate this method using realistic laboratory and quality-assessment data.
- To enhance the interpretation of imprecision profile plots.
Main Methods:
- Direct estimation of imprecision profiles from replicated assay results.
- Computation of 95% confidence intervals for these profiles.
- Utilizing data typical of routine laboratory or external quality assessment programs.
Main Results:
- Confidence intervals provide a clear visual representation of estimation uncertainty.
- The method effectively incorporates data quantity and distribution into profile assessment.
- Imprecision profiles with confidence intervals offer a comprehensible summary of complex assay performance data.
Conclusions:
- The proposed method improves the reliability of immunoassay imprecision profiling.
- Confidence intervals enhance the interpretability and trustworthiness of imprecision data.
- A computer program is available to facilitate the estimation and plotting of profiles with confidence intervals.
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