Clinical practice guidelines as learned treatises: understanding their use as evidence in the courtroom.

It is important for forensic experts to understand how clinical practice guidelines may enter the courtroom, what role they may play in a trial, and how they relate to expert testimony. Guidelines enter the record in several different ways and in several types of cases, typically with the assistance of an expert witness. A common vehicle for their introduction is the learned-treatise exception to the hearsay rule. Case law before and after Daubert v. Merrell Dow Pharmaceuticals, Inc. helps to elucidate the scrutiny that courts may direct toward medical texts proffered as evidence. This article discusses the implications of different rules and relevant case law for the forensic psychiatrist. The discussion notes important considerations for the expert witness, such as how guidelines may affect the expert's role, concerns about the reliability and relevance of scientific evidence, and questions about whether guidelines will be used for inculpatory or exculpatory purposes in medical malpractice trials.