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  1. Placebo-controlled trials : when are they needed ?

    Article, Communication - En anglais

    Schizophrenia Research. Symposium. Toronto, CAN, 1997/09/18.

    Randomized controlled trials require that patients be assigned to either receive the medication under investigation or to a control condition.

    It is not necessary that the control arm of the trial involve a placebo : it may consist of a different drug or conventional treatment.

    However, this can lead to serious problems in interpretation if the trial concludes that there is no statistically significant difference between the groups.

    In studies where a placebo arm was not used, it is extremely difficult to determine if this lack of a difference was due to equal effectiveness of the treatments, or was the result of a Type II error ; i.e., erroneously concluding that there was no difference when one. in fact, existed.

    This may have been due to poor design or execution of the trial, or to low power resulting from an insufficient number of subjects in the study.

    The need for placebo controls can be minimized if there is assurance that the trial is well-designed and executed, and this may require external review of studies, especially those which are not peer-reviewed.

    If a placebo arm is deemed necessary, then it may be necessary to ensure that certain condition are met. (...)

    Mots-clés Pascal : Schizophrénie, Essai clinique, Placebo, Neuroleptique, Psychotrope, Ethique, Consentement éclairé, Méthodologie, Randomisation, Homme, Psychose

    Mots-clés Pascal anglais : Schizophrenia, Clinical trial, Placebo, Neuroleptic, Psychotropic, Ethics, Informed consent, Methodology, Randomization, Human, Psychosis

    Logo du centre Notice produite par :
    Inist-CNRS - Institut de l'Information Scientifique et Technique

    Cote : 99-0257219

    Code Inist : 002B02B03. Création : 16/11/1999.