Impact of clinical and socio-economic factors and self-perception of health on the functionality of the elderly

OBJECTIVES: Our objective was to verify factors determining the functional level of Brazilian elderly people. METHOD: This is a secondary analysis of the 2013 National Health Survey (NHS) conducted by the Brazilian Institute of Geography and Statistics (IBGE). The association between functional levels and sociodemographic and clinical characteristics was tested by linear regression adjusted for self-perception of health (SPH) using the Epi Info™ program version 7.2.1. P-values lower than 0.05 were regarded as statistically significant. Functionality was assessed by a functional score developed based on the NHS questions. RESULTS: Univariate analyses revealed that, except for ethnicity, all socio-economic and clinical variables were significantly related to ease of performing basic activities of daily living (BADL) and instrumental activities of daily living (IADL). Upon multiple linear regression analysis, the most significant variables were age, SPH, stroke, and mental illness (p < 0.001). SPH significantly explained the differences in IADL (5.1%, p < 0.01) and BADL (3.4%, p < 0.01) levels even when controlling for the other variables. Stroke and mental illness were related to lower functional scores, both in IADL (20.5%, p < 0.01 and 19.1%, p < 0.01, respectively) and in BADL (13.5%, p < 0.01 and 7.6%, p < 0.01, respectively). CONCLUSIONS: The functional status of the elderly could be explained by constitutional factors (age) and modifiable variables (stroke, mental illness, and SPH), many of which still have a great impact on Brazilian morbidity and mortality. The highlight of SPH suggests that it may be an indicator of health care quality for the Brazilian elderly.