The conflict between randomized clinical trials and the therapeutic obligation.

The central dilemma concerning randomized clinical trials (RCTs) arises out of some simple facts about causal methodology (RCTs are the best way to generate the reliable causal knowledge necessary for optimally-informed action) and a prima facie plausible principle concerning how physicians should treat their patients (always do what it is most reasonable to believe will be best for the patient). A number of arguments related to this in the literature are considered. Attempts to avoid the dilemma fail. Appeals to informed consent and mechanisms for minimizing the resulting harm are important for policy, but informed consent is problematic and mechanisms for minimization of harm do not address the dilemma. Appeals to some sort of contract model of justification are promising and illuminating.