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Assessing reproducibility by the within-subject coefficient of variation with random effects models
1Biostatistics and Research Data System, Merck Research Laboratories, Rahway, New Jersey 07065, USA.
Biometrics
|December 1, 1996
Summary
This study introduces within-subject coefficient of variation (WCV) for measurement reliability. WCV is often preferred over intraclass correlation for reproducible biochemical markers when measurement scales have intrinsic meaning.
Area of Science:
- Biostatistics
- Biomedical Engineering
- Clinical Chemistry
Background:
- Assessing measurement reproducibility is crucial in scientific research.
- Biochemical markers for bone turnover require reliable measurement techniques.
- Existing methods like intraclass correlation have limitations.
Purpose of the Study:
- To evaluate the utility of within-subject coefficient of variation (WCV) for measurement reproducibility.
- To compare WCV with intraclass correlation for assessing reliability.
- To derive confidence intervals for WCV.
Main Methods:
- The study considers both maximum likelihood and moment confidence intervals for WCV.
- Asymptotic distributions are used to obtain these confidence intervals.
- The performance of WCV is analyzed for normal and log-normal data distributions.
Main Results:
- Within-subject coefficient of variation (WCV) is proposed as a reliable metric for measurement reproducibility.
- WCV is advantageous when measurement scales possess intrinsic meaning.
- Intraclass correlation may be more suitable for studies with a fixed subject population.
Conclusions:
- WCV offers a valuable alternative for assessing measurement reliability, particularly for biochemical markers.
- The choice between WCV and intraclass correlation depends on the nature of the measurement scale and study design.
- Confidence intervals for WCV provide a quantitative measure of precision for reproducibility assessments.
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