title: Use of a Bayesian approach to decide when to stop a therapeutic trial: the case of a chemoprophylaxis trial in human immunodeficiency virus infection.
abstract: From 1996 to 1998, a phase III, placebo-controlled, therapeutic trial was conducted in Abidjan, Ivory Coast, to assess the efficacy of cotrimoxazole prophylaxis in reducing severe morbidity in adults at early stages of human immunodeficiency virus infection. The authors used the real data from this trial to simulate three Bayesian interim analyses. Three prior distributions were considered: a noninformative one, a skeptical one, and one based on external information. The posterior distribution was calculated by using directed acyclic graphs and Gibbs sampling. This Bayesian approach showed different results according to the prior distribution chosen. Although use of the noninformative prior would have led to stopping the trial at the same time that the frequentist approach would have, the skeptical prior would have led to continuing it, and the prior based on external data would have led to stopping it 1 year earlier.
authors.affiliation: INSERM U 593, Université Victor Segalen Bordeaux 2, 146 rue Léo-Saignat, 33076 Bordeaux Cedex, France. Alphonse.Kpozehouen@isped.u-bordeaux2.fr
authors.forename: Alphonse
authors.initials: A
authors.lastname: Kpozèhouen
authors.forename: Ahmadou
authors.initials: A
authors.lastname: Alioum
authors.forename: Xavier
authors.initials: X
authors.lastname: Anglaret
authors.forename: Philippe
authors.initials: P
authors.lastname: Van de Perre
authors.forename: Geneviève
authors.initials: G
authors.lastname: Chêne
authors.forename: Roger
authors.initials: R
authors.lastname: Salamon
mesh_terms: D000890:Anti-Infective Agents / Q000627:therapeutic use*; D001499:Bayes Theorem; D017326:Clinical Trials, Phase III as Topic; D007560:Cote d'Ivoire; D023381:Endpoint Determination / Q000379:methods*; D015658:HIV Infections / Q000188:drug therapy*; D006801:Humans; D016032:Randomized Controlled Trials as Topic; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000627:therapeutic use*
chemical_list: D000890:Anti-Infective Agents; D015662:Trimethoprim, Sulfamethoxazole Drug Combination