Assay Validation Using the Concordance Correlation Coefficient

TLDR

The concordance correlation coefficient is a newly proposed reproducibility index for assays, methods, and instruments. It combines precision and accuracy measurements, enables sample‑size calculation based on allowable loss criteria, and supports reproducibility validation through confidence‑interval analysis. An example application using real data demonstrates its practical use.

Abstract

A new reproducibility index, called the concordance correlation coefficient, has been proposed (Lin, 1989, Biometrics 45, 255-268) to evaluate the reproducibility of an assay, method, or instrument. This index includes measurements of precision and accuracy. Based on certain criteria about the allowable losses in precision and accuracy, one can compute the sample size requirement. One can also meaningfully validate the reproducibility using the confidence interval approach. For illustration, an application using actual data is given.