[Quality of life of older people with depression and dependence: validity of the SF-12 (short form health survey) questionnaire].

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.