A causal model for joint evaluation of placebo and treatment-specific effects in clinical trials.

ABSTRACT: Evaluation of medical treatments is frequently complicated by the presence of substantial placebo effects, especially on relatively subjective endpoints, and the standard solution to this problem is a randomized, double-blinded, placebo-controlled clinical trial. However, effective blinding does not guarantee that all patients have the same belief or mentality about which treatment they have received (or treatmentality, for brevity), making it difficult to interpret the usual intent-to-treat effect as a causal effect. We discuss the causal relationships among treatment, treatmentality and the clinical outcome of interest, and propose a causal model for joint evaluation of placebo and treatment-specific effects. The model highlights the importance of measuring and incorporating patient trea

SUBMITTER: Zhang Z 

PROVIDER: S-EPMC4133792 | biostudies-literature | 2013 Jun

REPOSITORIES: biostudies-literature