RT Book, Section A1 Eapen, Zubin J. A2 Lopes, Renato D. A2 Harrington, Robert A. SR Print(0) ID 57836830 T1 Chapter 16. Lessons from Notable Examples in Observational Research T2 Understanding Clinical Research YR 2013 FD 2013 PB The McGraw-Hill Companies PP New York, NY SN 978-0-07-174678-6 LK accessmedicine.mhmedical.com/content.aspx?aid=57836830 RD 2024/03/28 AB The imperative for sound clinical research continues to increase in response to the demand for evidence-based, guideline-driven medicine. To increase the quality of health care and improve clinical decision-making, innumerable studies have contributed to a hierarchy of evidence for each disease state. The randomized trial often stands at the pinnacle of this hierarchy, yielding the highest level of evidence through a blinded experiment of an intervention or treatment. Preceding observational studies often generate the equipoise and hypotheses for randomized trials. In other instances, observational research can be the best vehicle for generating the evidence. The experimentation inherent in a randomized trial might be unnecessary, inappropriate, or even impossible under certain circumstances. Political, legal, and ethical barriers also can prohibit randomized trials. Increasingly, the costs of large trials are creating another barrier to generating randomized evidence, reducing incentives for funding the head-to-head trials needed to understand the real-world effectiveness of novel therapies. It is therefore important, in the context of the emerging field of comparative effectiveness research, to understand the value and appropriateness of observational research versus randomized trials in answering different clinical questions (Figure 16–1). Prior observational studies, both successes and failures, can inform future efforts in comparative effectiveness.