Prevalence of chronic diseases and factors associated with multimorbidity in the Brazilian Amazon: a cross-sectional population-based study, 2019.

This study aimed to assess the prevalence of multimorbidity and associated factors in Manaus, Brazil. A cross-sectional population-based survey was conducted in 2019 using probabilistic sampling. Multimorbidity was defined as two or more self-reported chronic diseases. Multimorbidity treatment was considered if participants received treatment for all their conditions. Limitations in daily activities were assessed using a 5-point Likert scale. Poisson regression was applied to estimate prevalence ratios (PR) of multimorbidity with 95% confidence intervals (95%CI). Out of 2,321 participants, 30.6% (95%CI 28.7-32.4%) had multimorbidity (mean: 2.99 ± 1.27 conditions), and 28.8% (95%CI 25.3-32.0%) of them were treated for all diseases. Back pain, hypertension, and hypercholesterolemia were the most common conditions, while mental disorders, renal disease, and other less frequent illnesses were most markedly associated with severe limitations in daily activities. Multimorbidity was higher in women (PR =1.46; 95%CI 1.28-1.66), older people (p < 0.001), and retired individuals (PR = 1.41; 95%CI 1.13-1.75). Nearly 30% of the population of Manaus live with multimorbidity, which is associated with socioeconomic determinants; among them, approximately one-quarter received multimorbidity treatment.