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Comparison of R- and two ICC-based approaches to sample size calculation when prevalence setting does not change between previous and future study. R method uses R1 and R2 for Arms 1 and 2, respectively, and equation 13. ICC method A uses ICC1 and ICC2 for Arms 1 and 2 and equation 14. ICC method B uses a single overall ICC and equation 15. See text for additional details.
