Prevalence of functional dependence and chronic diseases in the noninstitutionalized Brazilian elderly: an analysis by dependence severity and multimorbidity pattern

Abstract

Background Despite the advancements in knowledge about health care for the elderly, important gaps persist regarding the effects of chronic diseases as epidemiological markers of the state of functional dependence. This study aimed to identify the prevalence of the severity of functional dependence in the Brazilian elderly and its association with chronic diseases and to verify the patterns of multimorbidity by dependence status.Methods This cross-sectional analytical study used data from the 2013 National Health Survey conducted in Brazil. The dependent variables were moderate and severe functional dependence in basic activities of daily living (BADLs) and instrumental ADLs (IADLs). The independent variables were defined based on the questions applied to measure each morbidity in a self-reported manner and asked as “Has a doctor ever diagnosed you as having (each disease)? Multimorbidity was considered present for the elderly with ≥ 2 chronic morbidities simultaneously. The association between functional dependence on BADLs and IADLs separately by severity and the independent variables was verified from crude and adjusted estimates of the point prevalence ratios and their 95% confidence intervals using the regression model Poisson with robust variance. To group diseases into patterns, exploratory factor analysis was used.Results BADLs with moderate dependence were prevalent in 25% of the elderly aged > 80 years. Among the severely dependent, these corresponded to > 40%. For IADLs, the percentage remained high, especially for elderly individuals at an early age, approximately 60% for moderate dependence and 70% for severe dependence. When changing the condition from moderate to severe dependence in BADLs, in the presence of other mental illnesses and stroke, the probability of dependence increased more than four times in the case of other mental illnesses and more than five times for stroke. There was a linear trend for dependence severity, both moderate and severe, whereas for severe dependence on IADLs, this same factor maintained a linear trend toward an increase in probability as the number of diseases simultaneously increased.Conclusions Chronic diseases are associated with functional dependence, with greater emphasis on mental illnesses and stroke, in severe disability, considering their acute negative effects.