Why we need observational studies to evaluate the effectiveness of health care

TLDR

The prevailing view that randomized trials are the gold standard and observational studies are of little value overlooks the practical limitations of RCTs, which can be unnecessary, inappropriate, impossible, or inadequate. The study calls for replacing the false conflict between proponents of exclusive randomized trials and those favoring observational data with a recognition of their complementary roles, urging researchers to pursue scientific rigor regardless of method.

Abstract

The view is widely held that experimental methods (randomised controlled trials) are the "gold standard" for evaluation and that observational methods (cohort and case control studies) have little or no value. This ignores the limitations of randomised trials, which may prove unnecessary, inappropriate, impossible, or inadequate. Many of the problems of conducting randomised trials could often, in theory, be overcome, but the practical implications for researchers and funding bodies mean that this is often not possible. The false conflict between those who advocate randomised trials in all situations and those who believe observational data provide sufficient evidence needs to be replaced with mutual recognition of the complementary roles of the two approaches. Researchers should be united in their quest for scientific rigour in evaluation, regardless of the method used.