Intraclass Correlation Coefficient

Download the SAS code below written by Dr. Luqiang Wang for finding point and interval estimates of the intraclass correlation coefficient (ICC) in a three-way crossed design with raters, subjects, and occasions.

Three-way ICC Estimation

The zipped file contains a small example data set as well as 3 separate SAS program files for:

  • Point and interval estimation of the ICC using means squares from the analysis of variance (ANOVA);
  • Bootstrap confidence intervals for the ICC using the Efron percentile method and the bias-corrected method;
  • Point and interval estimation of the ICC by a custom Gibbs sampler implementation of the method of Monte Carlo Markov chains.