Cross-cultural adaptation of the quality of life assessment scale on Alzheimer disease.

OBJECTIVE To present the internal validation of the quality of life (QOL) evaluation scale for patients with Alzheimer's disease (AD) and their caregivers/family members, proposed by Logsdon et al. METHOD The scale was adapted through translation, back translation and equivalence evaluation. The Portuguese version was administered to a sample of 40 patients with mild to moderate AD according to NINCDS ADRDA and DSM-III-R criteria, and also to their respective caregivers/family members. RESULTS The reliability of the instrument was excellent, both in the intra and the inter-examiner test-retest. The correlation coefficients for the intra-examiner assessment were 0.87/0.95/0.95 (p < 0.001)) for the patient, family and caregiver versions, respectively. The correlation coefficients for the inter-examiner assessment were 0.76/0.96/0.93 (p < 0.001) for the patients, family and caregiver versions, respectively. The reliability was excellent for both the patient and the relatives' versions in relation to the patient's QOL (alpha = 0.81 and 0.85, respectively), and also in relation to the caregiver's QOL (alpha = 0.84). CONCLUSION The adapted version of the instrument proved to be straightforward and brief, presenting excellent stability and reliability. The Portuguese version can be obtained by contacting the first author.