Background and Objectives: Multimorbid patients require intensive treatment for their diseases. However, little research has been given to their treatment adherence as part of its management. This study aims to determine the prevalence and characteristics of chronic disease multimorbidity in Indonesia, alongside its treatment nonadherence. Materials and Methods: We conducted a cross-sectional study using the fifth Indonesian Family Life Survey database among adult subjects aged ≥ 15 years with multimorbidity. Our descriptive and multivariate analyses include sex, age, formal education, ethnicity, geographic residence, demographic residence, household size, insurance ownership, annual income, current self-perceived health status, missing active days, smoking behavior, and body mass index. Results: We identified 3515 multimorbid patients, constituting 30.8% prevalence across chronic disease patients. Hypertension was found to be a prevalent component of multimorbidity (61.2%), followed by digestive diseases (44.5%) and arthritis (30.3%). We identified that 36.4% of the subjects were nonadherent to their chronic disease treatment. Characteristics associated with nonadherence were found to be a good self-perception of health (aOR 1.79, 95% CI 1.54-2.08), active smoking behavior (aOR 1.51, 95% CI 1.14-1.99), no smoking behavior (aOR 1.44, 95% CI 1.08-1.90), missing seven active/productive days or less in the past month due to poor health (aOR 1.36, 95% CI 1.10-1.68), no insurance ownership (aOR 1.20, 95% CI 1.04-1.39), age of 15-65 years (aOR 1.25, 95% CI 1.01-1.55), income below IDR 40 million (aOR 1.23, 95% CI 1.04-1.46), and household size of 2-6 people (aOR 1.17, 95% CI 1.01-1.36). Conclusions: While the prevalence of multimorbidity in Indonesia is generally similar to that observed in previous studies, we have identified patient characteristics related to nonadherence. We suggest that patient's nonadherence was primarily dictated by their self-perception of health and treatment complexity. With the longstanding issue of nonadherence, this study indicated the need to consider creating patient-tailored treatment programs in clinical practice to improve adherence by considering individual patients' characteristics.
Keywords: disease management; epidemiological factors; health determinants; multimorbidity; treatment adherence and compliance.