Functional limitation in the older Brazilian adults: Association with multimorbidity and socioeconomic conditions

The aim of this study was to assess the association between multimorbidity and the presence of functional limitation in basic (BADL) and instrumental activities of daily living (IADL) among Brazilian older adults and to verify whether this association is moderated by socioeconomic conditions. Cross-sectional study with data from the Brazilian National Health Survey (PNS) (2019) for the Brazilian population aged 60 years and over. The dependent variables were functional limitation, based on self-reported difficulty in performing one or more activities of daily living, including six BADL (feeding, bathing, using the toilet, dressing, crossing a room on the same floor and getting out of bed) and four IADL (shopping, managing money, taking medication and using transportation). The independent variables were multimorbidity (presence of two or more self-reported chronic diseases) and socioeconomic measures (per capita household income, asset score, and education level). The association between multimorbidity and outcomes was assessed using adjusted logistic regression models. The moderating effect of socioeconomic conditions on the association between multimorbidity and functional limitations was assessed by including an interaction term. The final sample consisted of 22,725 individuals. The prevalence of functional limitation was 8.5% (95%CI: 7.9-9.2) and 18.6% (95%CI: 17.8-19.5) in BADL and IADL, respectively. Multimorbidity was associated with BADL [OR: 2.30 (95%CI: 1.93-2.74)] and IADL [OR: 2.26 (95%CI: 1.98-2.57)]. The odds of functional limitation were higher among individuals with lower levels of education and income, but there was no interaction between multimorbidity and socioeconomic position measures. Multimorbidity was associated with functional limitation (BADL and IADL) and socioeconomic conditions, and this association was constant across socioeconomic position levels.