Power analyses and sample size calculations are important parts of many research projects. Often, before data are even collected, it is necessary to calculate and justify the required sample size for ...

Over-dispersed count data are frequently observed in clinical trials where the primary endpoint is occurrence of clinical events. Sample sizes of comparative clinical trials with these data are ...

This is a preview. Log in through your library . Abstract Miettinen (1968, Biometrics 24, 339-352) presented an approximation for power and sample size for testing the differences between proportions ...