Critics of medical malpractice litigation believe that expert testimony is often anecdotal and biased. To remedy this problem, several have recently suggested that attorneys should provide and courts should seek reliable empirical evidence of actual clinical norms. Their suggestion should be welcomed. If our expectations are realistic and the design pitfalls are avoided, greater use of use of empirical research will improve the fairness of malpractice adjudication. At least in theory, it could be useful in both the "easy" cases (where it reveals that a consensus standard of care exists) and also some of the harder cases (where clinical practices vary). At the same time, this evidence will make the phenomenon of medical variation - often without any clinical basis - more visible to judges, highlighting the need to give juries better guidance on issues such as the amount of permissible variation around a single norm and the identification of unacceptable schools of thought. Ideally, the new evidence of inexplicable variation in clinical practice will also encourage courts to abandon their conclusive deference to medical custom in favor of a standard of care that makes custom (when it exists) relevant, but not dispositive.
Philip G. Peters Jr., Empirical Evidence and Malpractice Litigation, 37 Wake Forest L. Rev. 757 (2002)