Depression in the elderly: Prevalence and associated factors

Abstract

Objectives: To determine the prevalence of depression and associated socio-demographic factors in primary care population in Portugal. Type of Study: Cross-sectional study Location: Centro de Saúde da Senhora da Hora, Unidades de Saúde Familiar Oceanos e Horizonte and Unidade de Saúde Atlântida, from Unidade Local de Saúde de Matosinhos (ULSM). Population: Subjects enrolled in the referred health centers that were 65 years of age or over, at the time of data collection. (N = 11.600). Methods: A cross-sectional study was conducted between May and September 2008, in 590 individuals over age 65, randomly selected from the lists of four health centers. Patients were interviewed using a questionnaire containing the short version of Geriatric Depression Scale (GDS) of Yesavage to evaluate probable depression, socio-demografic data and type of family. A GDS score greater than four was set to diagnose probable depression. Associations between variables were tested with bi-variate analysis and logistic regression using SPSS and Excel Software. Results: Of the 590 patients selected 449 patients agreed to participate (response rate: 76,1%). No differences were found between respondents and non-respondents regarding gender and age. The prevalence of depression was 42,1% (CI 95%, 37,5-46,7). This was significantly higher in women (p < 0,001), among those with less than four years of formal education (p = 0,008), and unmarried individuals (p = 0,002). The association between depression and female gender remained significant after regression analysis. (OR = 3,42; 95% CI, 2,12-5,38) Conclusions: The prevalence of probable depression is higher than that found on the existing studies. The association between depression and female gender is in agreement with the literature. This study is, according to our knowledge, the first to address this issue in primary health care in Portugal.