Sample size calculations for educational interventions: principles and methods

Excerpt

You are your department’s director of obstetrical anesthesia and you plan to introduce programmed intermittent epidural bolus analgesia to your hospital. In doing so, you will need to teach your anesthetic and nursing colleagues about the rationale for this technique as well as how to program and use the new required pumps. You plan a mixture of teaching rounds and online learning modules. Building on research showing that repeated testing can enhance long-term retention of information,1 you plan to integrate weekly quizzes consisting of different question formats (e.g., short-answers, multiple-choice items). To determine whether repeated quizzes promote learning, you would like to conduct an experiment, where half of the individuals receive weekly quizzes and the other half receive additional study material. One month after the completion of the educational program, you would like to test your colleagues’ knowledge of the new technique to determine whether weekly quizzes enhanced retention of information presented. You must now determine how many individuals you will need to be sure your intervention has worked. …