ReviewFrom Randomized Controlled Trials to Observational Studies
Section snippets
Randomized Controlled Trials
Randomized controlled trials are the main means of establishing the efficacy of lifestyle interventions or treatment approaches (or both) in well-defined populations of healthy and diseased individuals. During drug development and early testing, randomized, placebo-controlled trials use precise clinical endpoints to determine the efficacy and safety of a new drug administered under strictly controlled conditions. Such studies are designed to minimize threats to internal validity, thus ensuring
Observational Studies
Observational studies can have a case-control or a cohort design. Case-control studies identify cases with and without the relevant outcome, then the effect of treatment or exposure is compared between the 2 groups of patients.13, 14 Because the research process involves looking back in time, case-control studies also are called retrospective studies. In cohort studies, patients are selected and subsequently observed over time for effects of treatment or exposure on the relevant outcome.14
Conclusions
Although randomized controlled trials are considered the gold standard in assessing treatment efficacy and safety of newly developed drugs, their results can be limited when applied to real-world clinical settings. Observational studies assess treatment effectiveness in patients in day-to-day clinical practice. Results from these studies can confirm and expand upon outcomes reported for selected populations in randomized controlled trials. Controlled head-to-head comparisons of therapies are
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Funding: The author received editorial support in the preparation of this manuscript funded by The Alliance for Better Bone Health (Procter & Gamble Pharmaceuticals and sanofi-aventis U.S., Inc). The author, however, was fully responsible for all content and editorial decisions and received no financial support or other form of compensation related to the development of the article.
Conflict of interest: The author is a consultant and speaker for The Alliance for Better Bone Health and has received research grant support.
Authorship: The author had access to the data and maintained complete control of manuscript development.