title: Monitoring clinical trials based on predictive probability of significance.
abstract: At a given point in a clinical trial, investigators may ask the question: "What is the likelihood of a significant result if the trial were continued?" One possible answer to this question is to examine a predictive probability of the significant difference with further patient accrual. [See, for example, Choi, Smith, and Becker (1985, Controlled Clinical Trials 6, 280-288).] This paper proposes and investigates the approach in trials for comparing the means of two normal populations. Two methods for calculating the predictive probability are examined. The results indicate that the predictive probability can be a useful conservative measure in monitoring trials.
authors.affiliation: Department of Biostatistics, Virginia Commonwealth University, Richmond 23298.
authors.forename: S C
authors.initials: SC
authors.lastname: Choi
authors.forename: P A
authors.initials: PA
authors.lastname: Pepple
mesh_terms: D001499:Bayes Theorem; D002986:Clinical Trials as Topic / Q000706:statistics & numerical data*; D003198:Computer Simulation; D011237:Predictive Value of Tests; D012494:Sampling Studies