Vitor Quality of Life Scale for the Elderly: evidence of validity and reliability

PURPOSE To assess validity and reliability of the Vitor Quality of Life Scale for the Elderly (VITOR QLSE). METHODS A sociodemographic questionnaire, a mental status questionnaire, the VITOR QLSE, the World Health Organization Quality of Life Instrument old module (WHOQOL-OLD), and the Baptista Depression Scale adult version (EBADEP-A) were administered to a non-probabilistic sample of 617 elderly persons living in Brazil. Exploratory factor analysis was performed to reduce the 70 items of the first version of the VITOR QLSE. Construct validity was then evaluated; the VITOR QLSE was tested against the WHOQOL-OLD and EBADEP-A. One hundred and ninety-two randomly selected participants completed the instrument again 7-15 days after the first interview, providing a test-retest reliability estimate. RESULTS Exploratory factor analysis reduced the 70 items to 48 items grouped into six domains: autonomy and psychological, environment, physical independence, family, health, and social domains. The total explained variance was 39.46 %. Cronbach's alpha for overall reliability was 0.93 and ranged from 0.79 for health to 0.90 for physical independence. Pearson's correlation coefficient (r) was 0.76 for test-retest reliability, and 0.56 and -0.57 for the correlation of VITOR QLSE scores with those of the WHOQOL-OLD and EBADEP-A, respectively. CONCLUSION The final version of the VITOR QLSE has 48 items grouped into six domains and shows adequate validity and reliability. The rapid aging of the population and reduced number of instruments in the Latin America, and more specifically in Brazil, assessing quality of life in the elderly justify the development of a valid and reliable tool.