Incidence of depression and associated factors in older adults in Bagé, Rio Grande do Sul State, Brazil

Abstract:

To evaluate the cumulative incidence of depression and its associated factors in the older population living in the urban area of the municipality of Bagé, Rio Grande do Sul State, Brazil, a prospective cohort study was conducted from 2008 to 2016/2017. The analysis was restricted to 615 older adults with complete information on the Geriatric Depression Scale (GDS-15), both at baseline and at follow-up, and who did not present depression in 2008. To calculate crude and adjusted incidence ratios and 95% confidence interval, Poisson regression with robust variance adjustment was used, including the baseline variables. A hierarchical model of four levels of determination was used. The variables were controlled for those of the same or of higher levels, and the p-value ≤ 0.20 was established to remain in the analysis model. In 2008, 523 older people did not have depression and 92 had been screened with the disease. In 2016/2017, of the 523 individuals without depression in the baseline measure, 10.3% tested positive at screening (incident cases), whereas 89.7% of the older adults remained free of the condition. Of the 92 older adults with depression in 2008, 32.6% continued to present depressive symptoms at follow-up and 67.3% had remission of symptoms. Leaving home once or never and being incapable of doing functional and instrumental activities of daily living were associated with a higher risk of positive screening for depression. The results reinforce the multidimensional and dynamic character of depression, which alternates short and long episodes, and may become recurrent and chronic.

Keywords:
Incidence; Health of the Elderly; Depression; Longitudinal Studies