A prospective observational study of decisional capacity determinations in an academic medical center

The main goals, of this observational study were to clarify and categorize decisional capacity assessments performed by a psychosomatic medicine (PSM) consult service at an academic medical center. Areas of investigation included types of decisional capacity requests, the relationship between Folstein Mini-Mental State Exam (MMSE) and PSM decisional capacity determination, psychiatric diagnoses of patients, and the agreement between primary clinician capacity assessment and that of the PSM clinician.

This was a prospective study of 100 consecutive decisional capacity consultations. Twelve requests were for second consultations for patients previously seen, for a net of 88 patients.

In 77 cases, patients lacked decisional capacity. Assessments for capacity to leave against medical advice (AMA), capacity to accept medical/surgical procedures, capacity to refuse medical/surgical procedures, and capacity to participate in discharge planning were nearly equally frequent. An MMSE cutoff score of < 21 was found to be 100% specific and 69% sensitive for identifying the patients without capacity, while a cutoff of < 24 was found to be 83% sensitive and 90% specific for identifying patients without capacity. The primary psychiatric diagnosis was a cognitive disorder in 52 cases. In 38 of the 39 cases where the primary team believed the patient lacked capacity, the PSM service agreed. In only two of the seven cases where primary teams believed patients had capacity did the PSM team agree.

The MMSE was a useful predictor of capacity determination by PSM personnel, but using MMSE alone results in a number of erroneous determinations. Cognitive disorders were the most common primary psychiatric diagnoses in decisional capacity cases. Primary teams tended to be more accurate when they found patients to lack capacity.