Case study: Conditional power
DOI link for Case study: Conditional power
Case study: Conditional power book
To illustrate the use of conditional power we will use the data from a 2×2 Phase III cross-over trial in patients that had difficulty sleeping due to a painful condition. The trial compared an active drug (B) to a placebo (A) on sleep maintenance as measured by the WASO time. WASO (Wake After Sleep Onset) time is a measure of the total time awake during a sleep session after first falling asleep. Decreasing WASO time is beneficial. There was a two-week wash-out period between the two treatment periods. The WASO times were obtained in a sleep laboratory using polysomnography and were assumed to be normally distributed. As with the other case studies, we have changed some of the details of the trial and used simulated data to illustrate its analysis.