Estimation of Sampel Size for agreement is trial using R

library(kappaSize)

Sample size for three categories, Estimated Kappa 0.8, Null Hypothesis 0.7, Prevalence of three categories is 10%, 60%, 30%. Type I error 5% and power 90%

Power3Cats(kappa0=0.7, 
           kappa1=0.8, 
           props=c(0.1,0.6,0.3), 
           raters=2, 
           alpha=0.05, power=0.90)

A minimum of 477 subjects are required for this study of interobserver agreement. Code language: JavaScript (javascript)