R version 4.5.1 (2025-06-13)
Platform: aarch64-apple-darwin20
Running under: macOS Tahoe 26.2
Matrix products: default
BLAS: /Library/Frameworks/R.framework/Versions/4.5-arm64/Resources/lib/libRblas.0.dylib
LAPACK: /Library/Frameworks/R.framework/Versions/4.5-arm64/Resources/lib/libRlapack.dylib; LAPACK version 3.12.1
locale:
[1] C.UTF-8/UTF-8/C.UTF-8/C/C.UTF-8/C.UTF-8
time zone: Europe/Istanbul
tzcode source: internal
attached base packages:
[1] stats graphics grDevices utils datasets methods base
other attached packages:
[1] magrittr_2.0.4
loaded via a namespace (and not attached):
[1] htmlwidgets_1.6.4 compiler_4.5.1 fastmap_1.2.0 cli_3.6.5
[5] tools_4.5.1 htmltools_0.5.9 otel_0.2.0 rmarkdown_2.30
[9] knitr_1.51 jsonlite_2.0.0 xfun_0.55 digest_0.6.39
[13] rlang_1.1.6 evaluate_1.0.5 29 Appendix: Power Analysis Details
The following power analysis results were generated using clinical scenarios and previous literature estimates.
29.0.1 HER2 Power Approach for the Number of Subjects Required
Analysis result: A minimum of 32 subjects are required for this study of interobserver agreement.
Warning: At least one expected cell count is less than five.
Study Explanation:
Researchers would like to determine the required sample size to test kappa0=0.4 vs. kappa1=0.6 with alpha=0.05 and power=0.8 in a study of interobserver agreement with 5 raters. Further suppose that the prevalence of the categories are 0.35, 0.05, 0.35, 0.05, and 0.20.
29.0.2 ER - Power Approach for the Number of Subjects Required
Analysis result: A minimum of 51 subjects are required for this study of interobserver agreement.
Study Explanation:
Researchers would like to determine the required sample size to test kappa0=0.4 vs. kappa1=0.6 with alpha=0.05 and power=0.8 in a study of interobserver agreement with 5 raters. Further suppose that the prevalence of the categories are 0.20, 0.10, and 0.70.
29.0.3 PR - Power Approach for the Number of Subjects Required
Analysis result: A minimum of 58 subjects are required for this study of interobserver agreement.
Study Explanation:
Researchers would like to determine the required sample size to test kappa0=0.4 vs. kappa1=0.6 with alpha=0.05 and power=0.8 in a study of interobserver agreement with 5 raters. Further suppose that the prevalence of the trait is 0.40.
29.0.4 Ki67 - Power Approach for the Number of Subjects Required
Analysis result: A minimum of 69 subjects are required for this study of interobserver agreement.
Study Explanation:
Researchers would like to determine the required sample size to test kappa0=0.4 vs. kappa1=0.6 with alpha=0.05 and power=0.8 in a study of interobserver agreement with 5 raters. Further suppose that the prevalence of the trait is 0.70.