Background: Depression and dependence have a great impact on the quality of life of older people.
Aim: To validate the SF-12 (short-form) health related quality of care questionnaire (HRQOL) as an alternative of the SF-36 to estimate health-related quality of life (HRQoL) and its association with depression and dependence in Chilean older people living in the community.
Material and methods: The questionnaire was answered by 4,124 Chilean older people (61% women). HRQoL was evaluated with the SF-36 questionnaire. The SF-12 questionnaire includes 12 items from the SF-36.
Results: The internal consistency of the SF-12 questionnaire was high (0.88). The effect size of the differences in the averages of the SF-12 and SF-36 scales was small (0.06-0.41). Good agreement was found between the physical and mental components of the SF-12 and SF-36 (0.94 and 0.89). Logistic regressions determined that people with dependence and depression have a higher risk of poor HRQoL. The figures for the physical component were, mild depression: odds ratio (OR) (95% confidence intervals (CI) = 3.28 (2.74-3.93), severe depression: OR (IC95%CI) = 4.66 (3.55-6.11), mild to moderate dependence: OR (95CI%) = 3.67 (2.97-4.54), severe dependence: OR (95%CI) = 13.06 (7.23-23.61). For the mental component, the figures were: mild depression: OR (95CI%) = 6.11(5.05-7.38), severe depression: OR (95CI%) = 22.01(14.47-33.49), mild to moderate dependence: OR (95CI%) = 1.59 (1.28-1.97), severe dependence: OR (95CI%) = 1.60 (1.04-2.47), adjusting for sociodemographic and health-related variables.
Conclusions: The validity of the SF-12 for measuring HRQoL was demonstrated. People with depression and dependence have a worse physical and mental quality of life.