The psychometric properties of the Competency Interview Schedule.

One of the most contentious issues in medical and legal practice is how to reliably assess the mental competence of individuals who consent or refuse psychiatric treatment. Current legislation does not provide clear definitions of what constitutes competence or incompetence to make a treatment decision. As a preliminary attempt to operationalize the concept of competency, we have developed a 15 item questionnaire. The present study reports on the psychometric properties of the instrument. Test-retest and interrater reliability results were good. The instrument was internally consistent and discriminated between individuals found competent and incompetent by the treating physician.