Convergent validity between SF-36 and WHOQOL-BREF in older adults.
OBJECTIVE
To compare the reliability and convergent validity of instruments assessing quality of life in Brazilian older adults.


METHODS
Cross-sectional study of 278 literate, community-dwelling older adults attending a municipal university for the elderly in Sao Carlos, SP, Southeastern Brazil between 2006 and 2008. The Brazilian versions of the SF-36 and WHOQOL-BREF instruments to assess quality of life were compared. Cronbach's alpha coefficient was used to estimate reliability and Pearson's correlation for comparison between the two scales.


RESULTS
Most of participants were women (87.8%) with a mean age of 63.83±7.22 years. Both scales showed an acceptable internal consistency - WHOQOL-BREF Cronbach's alpha was 0.832 and SF-36 was 0.868. There was a weak (r ≤ 0.6) correlation between the related fields in the two questionnaires.


CONCLUSIONS
The SF-36 and WHOQOL-BREF are reliable instruments for clinical and research uses in Brazilian older women. To select one, researchers should consider which aspects of quality of life they aim to capture because of weak convergent validity signs. This study's results indicate that WHOQOL-BREF may be more relevant to evaluate changes in the quality of life of older women because it prioritizes responses to the aging process and avoids focusing on impairment.
Paula Costa
PC
Castro
Patrícia
P
Driusso
Jorge
J
Oishi
D000368:Aged; D000369:Aged, 80 and over; D001938:Brazil; D003430:Cross-Sectional Studies; D004522:Educational Status; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011594:Psychometrics / Q000295:instrumentation*; D011788:Quality of Life; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D014944:World Health Organization