Clinical determination of mental competence. A theory and a retrospective study

In an attempt to establish a method for determination of mental competence, a two-part investigation was undertaken. First, a model for mental competence was devised that would be applicable across a broad range of neurologic disorders; this model was based on a patient's ability to make complex decisions. Second, a retrospective analysis of competence in 92 inpatients on a neurobehavioral service was carried out. The model was a useful way to view competence, at least in this population. Competence could be classified as operational, limited to a single cognitive domain, or as general, cutting across all domains in a way for which no compensation could be devised. The results suggest that a model of competence based on analysis of individual cognitive operations will provide a sound clinical approach to a common problem that is presently not well characterized.