title: Interim analyses in clinical trials: classical vs. Bayesian approaches.
abstract: This paper concerns interim analysis in clinical trials involving two treatments from the points of view of both classical and Bayesian inference. I criticize classical hypothesis testing in this setting and describe and recommend a Bayesian approach in which sampling stops when the probability that one treatment is the better exceeds a specified value. I consider application to normal sampling analysed in stages and evaluate the gain in average sample number as a function of the number of interim analyses.
mesh_terms: D001499:Bayes Theorem; D002986:Clinical Trials as Topic; D006801:Humans; D011336:Probability; D013997:Time Factors