Correlation among three psychological scales used in research of caregivers for patients with Alzheimer's disease

This study was conducted to assess whether three scales commonly used in psychological research of Alzheimer's disease caregivers—Caregiver Burden Interview, Life Satisfaction Index-Z, and Geriatric Depression Scale—measure similar or different aspects of mental health. Responses from 244 nonprofessional caregivers were used to estimate factor structure, intercorrelation, and independent variables associated with the three scales. Self-rated health was the only variable significantly associated with scores on all three scales. Financial concern and number of weekly telephone calls were associated with total scores on the Satisfaction and Depression scales. Factor models of five, three, and six factors were fitted for the Burden, Satisfaction, and Depression scales, respectively. Correlations of factor scores and canonical variables among the scales did not yield strong associations between subsets of items. Although a few common aspects of caregiving influence scores of all three techniques, the facets of caregivers' psychology assessed by the three scales appear to be different.