Assay Validation Using the Concordance Correlation Coefficient

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.