title: [How may practitioners interpret the results of clinical trials?]
abstract: To correctly interpret the results of a randomised controlled trial (RCT), practitioners have to spot bias and other potential problems present in the trial. Internal as well as external validity of the trial are linked to the presence of such bias. The internal validity is ensured by a clear definition of the objectives of the trial. The number of patients to be included in the trial is calculated on the basis of the main objective of the trial and more precisely on the basis of the primary endpoint selected to assess the efficacy of treatment. This is the best way to ensure that the statistical significance of the result may have a clinical relevance. Internal validity depends also on the process of patients selection, the methods used to ensure comparability of groups and treatments, the criteria employed to assess efficacy, and the methods for the analysis of data. External validity refers to subjects that have been excluded from the trial, limitations of RCTs, as well as the coherence and clinical relevance of the trial. Internal validity has to be fueled by external validity.
authors.affiliation: SHU Psychiatrie Adultes, Hôpital Sainte Marguerite, 13274 Marseille Cedex 9, France. Electronic address: jazorin@ap-hm.fr.
authors.forename: J-M
authors.initials: JM
authors.lastname: Azorin
authors.affiliation: SHU Psychiatrie Adultes, Hôpital Sainte Marguerite, 13274 Marseille Cedex 9, France.
authors.forename: M
authors.initials: M
authors.lastname: Adida
authors.affiliation: Centre de Pharmacologie Clinique et Evaluations Thérapeutiques (AP-HM), UHC « La Timone », 28 bd Jean Moulin 13385 Marseille, France.
authors.forename: O
authors.initials: O
authors.lastname: Blin
authors.affiliation: Service de Pharmacologie Clinique, APHM, Hôpital Sainte Marguerite, CAP-TV, 13274 Marseille, France.
authors.forename: N
authors.initials: N
authors.lastname: Simon
authors.affiliation: Service de Psychiatrie Adultes, CHU Saint-Etienne, 5 chemin de la Marendière, 42055 Saint-Etienne Cedex, France.
authors.forename: E
authors.initials: E
authors.lastname: Fakra
authors.affiliation: SHU Psychiatrie Adultes, Hôpital Sainte Marguerite, 13274 Marseille Cedex 9, France.
authors.forename: M
authors.initials: M
authors.lastname: Cermolacce
authors.affiliation: Service de Psychiatrie, CH Martigues, 13698 Martigues Cedex, France.
authors.forename: T
authors.initials: T
authors.lastname: Bottai
authors.affiliation: Faculté de Médecine de Nice, UNSA, 28 avenue de Vallombrose 06107 Nice, France.
authors.forename: D
authors.initials: D
authors.lastname: Pringuey
authors.affiliation: Service d'explorations fonctionnelles du système nerveux, Clinique du sommeil, CHU de Bordeaux, Place Amélie Raba-Léon, 33076 Bordeaux, France.
authors.forename: J-A
authors.initials: JA
authors.lastname: Micoulaud-Franchi
authors.affiliation: SHU Psychiatrie Adultes, Hôpital Sainte Marguerite, 13274 Marseille Cedex 9, France.
authors.forename: R
authors.initials: R
authors.lastname: Belzeaux
authors.affiliation: Pôle de Psychiatrie des Adultes, CHU Robert Debré, Avenue du Général Koenig, 51092 Reims Cedex, France.
authors.forename: A
authors.initials: A
authors.lastname: Kaladjian
mesh_terms: D015982:Bias; D003627:Data Interpretation, Statistical; D006801:Humans; D007389:Internal-External Control; D010819:Physician's Role; D010820:Physicians; D016032:Randomized Controlled Trials as Topic / Q000592:standards / Q000706:statistics & numerical data*; D015203:Reproducibility of Results
keywords: Biais; Bias; Essai contrôlé randomisé (RCT); External validity; Internal validity; Randomised clinical trial (RCT); Validité externe; Validité interne