RCTs are not necessary for reliable causal inference

No one denies that RCTs are powerful experimental designs—and that their power stems from the ability to control numerous sources of bias and confounding. However, to refer to RCTs as the “gold standard” of evidence suggests that they are more. Specifically, one may be led to assume that RCTs are necessary for reliable causal inference or that RCTs are guaranteed to deliver reliable results. A number of philosophers of medicine have in the past decade or so argued that these stronger claims do n