ABSTRACT
Protocols for case-control studies usually require a statistical calculation of the required sample size and power of the proposed study. To some this may seem to be a perfunctory exercise. However, in order to compute power or required sample size, one must understand the objectives of the study, the measurements to be used, the hypotheses to be tested, and the planned statistical analysis. Indeed, one can often learn a lot about the proposed study by reading the section on sample size first.
