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The Impact of Restrictive Entry Criterion During the Placebo Lead‐in Period
Author(s) -
Landin R.,
DeBrota D. J.,
DeVries T. A.,
Potter W. Z.,
Demitrack M. A.
Publication year - 2000
Publication title -
biometrics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.298
H-Index - 130
eISSN - 1541-0420
pISSN - 0006-341X
DOI - 10.1111/j.0006-341x.2000.00271.x
Subject(s) - placebo , placebo response , lead (geology) , medicine , population , depression (economics) , randomized controlled trial , research design , clinical trial , sample size determination , physical therapy , statistics , alternative medicine , mathematics , environmental health , pathology , geomorphology , geology , economics , macroeconomics
Summary. In the study of depression, most randomized clinical trials have design features that attempt to sample from a stable patient population. One commonly used design feature is to require patients to maintain some minimum baseline symptom severity score during a placebo lead‐in period. One intent of this design feature is to evaluate the behavior of patients prior to administration of active medication. If, during the lead‐in period, patients do not maintain minimum symptom severity, the patients are excluded from the remainder of the study, the theory being that the excluded patients are not part of a stable patient population and hence are not likely to demonstrate efficacy of a truly effective treatment. This presentation investigates the effectiveness of a restrictive entry criterion and proposes an alternative explanation for what is usually defined as placebo response.