There is substantial interest in using observational epidemiologic research in combination with randomized clinical trials (RCTs) and meta-analyses to support decisionmaking by regulators, payers, and physicians. Nevertheless, even well-designed and well-conducted observational studies are often viewed with skepticism. This lingering  distrust comes, in part, from the well-accepted use of clinical trials compared with a widespread lack of familiarity with the principles for good conduct in observational research. The solution lies in sound guidelines for evaluating observational studies, especially studies that may prove useful for evaluating clinical effectiveness. Such guidance would help to focus on the quality and relevance of the evidence, whatever the study design.

Epidemiology, Volume 22, Number 3, May 2011