Objectives: To develop a valid and reliable instrument for rating quality of life in persons with late-stage Alzheimer's disease and other dementing illnesses.
Design: A group of clinicians with extensive experience in dealing with dementia patients developed by consensus the Quality of Life in Dementia Scale (QUALID), an 11-item scale. The window of observation for each subject was 7 days. A 5-point scale captured the frequency of each item (total score ranging from 11 to 55). Lower scores reflected a higher quality of life (QOL). Validity was assessed by comparison with other measures.
Setting: Dementia special care unit.
Participants: Professional caregivers of 42 patients.
Measurements: QUALID, Mini-Mental State Exam (MMSE), Physical Self-Maintenance Scale (PSMS), Neuropsychiatric Inventory (NPI), and Geriatric Depression Scale (GDS).
Results: QUALID scores ranged from 12 to 45 points and were skewed toward higher QOL (lower scores). Internal consistency of items was high, as were test-retest reliability and consistency across recorders. As expected, there was no relationship between QUALID and MMSE or PSMS scores, but there was a statistically significant, although moderate, relationship between QUALID and NPI, and GDS scores.
Conclusion: The QUALID is a reliable and valid scale, administered to caregivers, for rating QOL in persons with late-stage dementing illness.