Psychiatry - life events and social support Alexandrino-Silva C et al. CLINICS 2011;66(2):233-238 Table 1 - Association among determinants and ‘‘old age symptomatic depression’’: percent (SE) and univariate odds- ratios (95% CI). The Sa˜ o Paulo Epidemiologic Catchment Area Study; N of subjects 60 years or older = 367. Control group (N = 298) Old age symptomatic depression (N = 69) Gender (% female) Lifetime anxiety disorder Life events Bereavement Perceived lack of social support Living alone Socioeconomic disadvantage Cognitive impairment Chronic somatic illness 61.7% (0.03) 4.4% (0.01) 71.5% (0.03) 7.1% (0.01) 46.0% (0.03) 14.4% (0.02) 35.9% (0.03) 3.4% (0.01) 67.1% (0.03) Acceptable validity has been demonstrated when self- reporting on serious illnesses or severe health conditions by comparing self-reports to medical records in general practice settings.26 Statistical Analysis The statistical program SAS 9.1 was used to calculate proportions for dichotomous variables. Standard errors were obtained for these proportions. We first examined the proportions of determinants in each group: cases and controls. Following, univariate logistic regressions models were built to obtain odds ratios verifying the associations between ‘‘old age symptomatic depression’’ and the set of hypothesized determinants (female gender, lifetime anxiety disorders, life events, bereavement, perceived lack of social support, living alone, socioeconomic disadvantage, current cognitive impairment, and chronic somatic illness). Next, we performed a back- ward stepwise logistic regression by including all variables simultaneously and then removing the non-significant ones, testing two-way interactions of gender and all other covariates, as gender can influence differently the other predictors evaluated. The final model was obtained with a backward elimination of non-significant variables using the Wald x2 test. In all analyses, the reference category was the control group which was defined as people aged 60 or more, with no lifetime depressive episode or dysthymia, and no lifetime subthreshold depression. All evaluations of sig- nificance are based on two-sided tests using the 0.05 level of significance. RESULTS For the purpose of this study, 375 subjects aged 60 years or more comprised the initial subsample. However, eight of them had a lifetime diagnosis of depressive episode or dysthymia according to ICD-10, but these symptomatology was not presented in the age period considered. As our aim was to verify the association of late life depressive symptoms with current social support and previous two years life events, these subjects were excluded from the analysis. Therefore, in this report, all analyses were performed in the subsample of 367 subjects aged 60 years or more (mean age 70.1 ¡ SD 7.1), representing 25.6% (SE 1.14) of the total sample (N = 1,464). In this subsample, 37 subjects presented a depressive episode with onset or recency after 60 years, the ‘‘late depression’’ subgroup (10.1%; SE 1.6), and 32 presented the above mentioned ‘‘late subthreshold depression’’ (8.7%; SE 1.4). These two 78.3% (0.05) 18.9% (0.05) 81.2% (0.05) 11.6% (0.04) 49.3% (0.06) 24.6% (0.05) 37.7% (0.06) 4.4% (0.02) 71.0% (0.06) Wald x2 6.47 15.11 2.64 1.56 0.25 4.17 0.08 0.16 0.39 P 0.0109 ,0.0001 0.1043 0.2118 0.6204 0.0413 0.7823 0.6886 0.5323 OR 2.2 5.1 1.7 1.7 1.1 1.9 1.1 1.3 1.2 95% CI 1.2-4.1 2.2-11.6 0.9-3.3 0.7-4.1 0.7-1.9 1.0-3.7 0.6-1.9 0.4-4.9 0.7-2.1 subgroups were collapsed into a broader ‘‘old age sympto- matic depression’’ group, comprised by 18.8% (SE 2.0) of the 367 subjects 60 years or older, with a mean age of 69.1 (SD 6.6). The remaining of the elderly subjects that reported never having had a lifetime depressive episode, dysthymia or subthreshold depression formed the control group (N = 298), corresponding to 81.2% (SE 2.0) of the subsample, with mean age 70.3 (SD 7.2). The gender distribution of the control group was 61.7% of female (N = 184) and 38.3% of male (N = 114), whereas the ‘‘old age symptomatic depres- sion’’ was formed by 78.3% of women (N = 54) and 21.7% of men (N = 15). Table 1 shows frequencies of each predictor considered herein in the two groups. In the univariate analysis, female gender was a determinant for ‘‘old age symptomatic depres- sion’’. Respondents with ‘‘old age symptomatic depression’’ were five times more likely to present a comorbid anxiety disorder, and were also more likely to live alone, when compared to the control group. Life events and bereavement were reported by a higher proportion of cases, although the comparison across groups was not significant. All other predictors had equal distributions across the case and control groups, with odds ratios close to 1. In the multivariate regression model (Table 2) lifetime anxiety disorder was associated with ‘‘old age symptomatic depression’’ (OR = 5.2, 95% CI 2.2-12.4), and an interaction effect between gender and other predictors was observed in this elderly sample. In the final adjusted models, the perceived lack of social support (OR = 3.5, 95% CI 1.1-12.1) was a predictor for ‘‘old age symptomatic depression’’ in men, whereas the presence of life events (OR = 2.4, 95% CI 1.1-5.6) was a predictor of this symptomatology for women. Table 2 - Determinants of ‘‘old age symptomatic depres- sion’’: final model of stepwise logistic regression (adjust- ed odds ratio and 95% CI). The Sa˜ o Paulo Epidemiologic Catchment Area Study; N of subjects 60 years or older = 367. 236 Lifetime anxiety disorder Male: Perceived lack of social support Life events Female: Perceived lack of social support Life events Old age symptomatic depression OR 5.2 3.5 0.5 0.7 2.4 95% CI 2.2-12.4 1.1-12.1 0.1-1.6 0.4-1.4 1.1-5.6 xw2 13.79 3.96 1.53 1.1 4.32 P 0.0002 0.0466 0.2165 0.2993 0.0376