Capacity to Make Treatment Decisions in Chinese Older Persons With Very Mild Dementia and Mild Alzheimer Disease

Abstract

This study aims at assessing mental competence in Chinese patients with mild and very mild dementia with a semistructured assessment method and the impact of repeated presentations of information on patients' mental competence. Subjects with mild and very mild dementia were compared with cognitively intact subjects. Chinese subjects were recruited from local social centers and residential hostels for the elderly in Hong Kong. Sixty-six Chinese community-dwelling older adults (aged from 65 to 87 years) were recruited. Clinical diagnosis was made by experienced geriatric psychiatrists. Subjects were assessed with the Mini-Mental State Examination and the Clinical Dementia Rating (CDR). Mental capacity to consent to treatment was assessed by using the Chinese version of the MacArthur Competence Assessment Tool-Treatment (MacCAT-T) and independent clinician ratings based on the definition in the Mental Capacity Act 2005 of the United Kingdom. Thirty-three (50%) participants were diagnosed with very mild or mild dementia (CDR = 0.5 or 1). In this group, 15 (45.5%) subjects were rated as mentally incompetent in clinician ratings. In the assessment of interrater reliability, the intraclass correlation coefficient of MacCAT-T summary scores among three raters ranged from 0.64 to 0.83. The MacCAT-T summary scores correlated significantly with clinician ratings, years of education, Mini-Mental State Examination score, and CDR. In contrast to the nonimpaired group, repeated presentation of information did not significantly improve capacity in the demented group. Results from this study suggest that even patients with very mild dementia in this population can show substantial deficits in decision-making capacity, and that improved capacity is not likely to result from repeated disclosure of information.