Logical Limits of the Randomized Controlled Trial Research Design

For many, and for obvious methodological reasons, the randomized control trial (“RCT”) is "the" (or "a") research design "gold standard" for those seeking data with possible causal implications. (For a nice quick description of RCTs click here.) In contrast, those interested in a clever, "tongue-in-cheek," "critique" of the pursuit of absolute research design "purity" might be interested in a 2003 "essay," Parachute use to prevent death and major trauma related to gravitational challenge: systematic review of randomized controlled trials, by Gordon CS Smith (Cambridge--medicine) et al. In the "essay" the authors observe that they could not find any "published research presenting results from randomized controlled trials of parachute use." Consequently, the essay "argues" that the empirical basis for the parachute's efficacy is "purely observational" and, moreover, that existing "observational" data on the parachute's apparent efficacy could potentially be explained by a "healthy cohort" effect.