The Concordance Correlation Coefficient for Repeated Measures Estimated by Variance Components

Abstract

The concordance correlation coefficient (CCC) is an index that is commonly used to assess the degree of agreement between observers on measuring a continuous characteristic. Here, a CCC for longitudinal repeated measurements is developed through the appropriate specification of the intraclass correlation coefficient from a variance components linear mixed model. A case example and the results of a simulation study are provided.

Keywords:

• Concordance
• Linear mixed models
• Longitudinal analysis
• Variance components

ACKNOWLEDGMENTS

We would like to thank the comments and suggestions of the two anonymous reviewers and associate editor that helped improve the current manuscript.