SSIZEBI: Stata module to calculate sample size and power for the comparison of two or more proportions
Abdel G. Babiker
ssizebi estimates power or total sample size for tests comparing K proportions. Power is calculated if n() is specified as a positive number, otherwise total sample size is estimated. ssizebi computes sample size/power for the (global/trend) unconditional chisquare test or the conditional test based on the hypergeometric distribution with the one-step Peto approximation to the odds ratio (OR). Sample size/power is calculated in the unconditional case under either local or distant alternatives. Under local alternatives (eg max(OR,1/OR)<=2), ssizebi uses the null covariance matrix under both null and alternative hypotheses. The unconditional test with local alternatives is the usual Pearson chisquare test. Local alternatives are assumed in the conditional case.
In order to set up a list of libraries that you have access to,
you must first login
or sign up.
Then set up a personal list of libraries from your profile page by
clicking on your user name at the top right of any screen.