Comparison of Three Different Assessments of Capacity to Consent in Dementia Patients

We compared clinical assessments of capacity to consent to medical treatment with results obtained using the MacArthur Competence Tool for Treatment (MacCAT-T). Capacity to consent to treatment with antidementia drugs was assessed in 53 outpatients suffering from mild to moderate dementia. The prevalence of incapacity as evaluated by the physician was 52.8% and differed from the MacCAT-T psychometric assessment (81.1%). A final interdisciplinary assessment combined the two independent measures as well as all other available and relevant information, and concluded that 60.4% did not have the capacity to consent to medical treatment. Possible reasons for disagreement are the differing definitions and thresholds used to evaluate whether the necessary abilities are present, in particular for assessments of the ability "understanding."