Clinical practice guidelines in the witness box: can they replace the medical expert?

Clinical practice guidelines aim to synthesise a vast amount of information to assist the physician or surgeon to select the most appropriate patient management, reduce treatment variation, reduce medical error and contain costs. They help the legal practitioner and courts determine the standard of care in medical negligence cases. However, they have numerous limitations. Their quality is highly variable and acceptance among the medical and legal professions is not universal. Good guidelines should be widely sourced, validly based on outcomes, widely accepted, updated regularly and include clear practice recommendations. Whatever their quality, they are not self-evident and do not cover precisely each and every clinical situation. They have rarely been incorporated into legislation and cannot be used in any court as the sole arbiter of a standard of practice. They must be supported by expert evidence and are themselves open to challenge. Adherence does not guarantee tortfeasor protection nor lack of adherence culpability.