Validation of the English Version of the Multimodal Assessment of Capacities in Severe Dementia (MAC-SD): A Cognitive and Functional Scale for Use in Severe Dementia

BACKGROUND: Most existing screening instruments that assess cognition and functioning in dementia suffer from floor effects, limiting their utility in severely demented patients. In 2015, the first author devised a new instrument, The Multimodal Assessment of Capacities in Severe Dementia (MAC-SD), to address this need. The MAC-SD Spanish version proved reliable, valid, and useful for evaluating patients with severe dementia. OBJECTIVE: This report presents the results of a field trial of the English version of the MAC-SD in a U.S. population. METHODS: The MAC-SD was administered to 40 participants with severe dementia along with gold standard measures of cognition and functioning in dementia (the Severe Mini-Mental State Exam, the Severe Impairment Battery, the Global Deterioration Scale, and the Barthel Index of Activities of Daily Living). Data analysis was performed to determine floor effects, reliability, validity, sensitivity to change, and clinical usefulness. RESULTS: The MAC-SD showed no significant floor effects, acceptable reliability, convergent validity with control measures, internal validity, and known groups validity. Of participants who scored the lowest possible on control measures, MAC-SD scores ranged widely. The MAC-SD was highly sensitive to change, and was able to detect changes not seen on control measures. CONCLUSIONS: The MAC-SD English version is reliable and valid for use in the cognitive and functional assessment of patients with severe dementia. It gives more detailed information than control instruments about the cognitive and functional abilities of patients with the most severe dementia, and is able to detect changes in these patients not shown by control measures.