Multimorbidity burden and hospitalisation outcomes in heart failure: a retrospective cohort study using Indonesian national health insurance claims data (2019–2024)

BACKGROUND: The expansion of universal health coverage (UHC) in many low- and middle-income countries (LMICs) has occurred alongside a growing burden of chronic disease and multimorbidity. Heart failure (HF) frequently coexists with multimorbidity, which is associated with worse hospitalisation outcomes. However, most evidence on multimorbidity and HF hospitalisation outcomes originates from older populations in high-income countries and nationally representative evidence from LMIC settings remains limited. We aimed to characterise multimorbidity burden among patients hospitalised with HF, evaluate associations with length of stay (LOS) and readmission and identify individual comorbidities associated with these outcomes. METHODS: We conducted a population-based retrospective cohort study using nationally representative, probability-weighted administrative claims from Badan Penyelenggara Jaminan Sosial Kesehatan, Indonesia's national health insurance programme (2019-2024). Adults (≥18 years) hospitalised with HF as the primary diagnosis were included. 12 prespecified comorbidities were ascertained from all available claims. Multimorbidity was defined as the number of comorbidities beyond HF. Outcomes were LOS and 30-day and 90-day HF-specific readmissions, analysed using survey-weighted linear and logistic regression adjusted for age and sex. RESULTS: Among 9018 patients contributing 12 461 HF episodes (mean age 59.8±13.1 years; 51.4% male), multimorbidity was present in 72.4%. Each additional comorbidity was associated with longer LOS (β 0.13 days; 95% CI 0.03 to 0.22), higher 30-day readmission odds (OR 1.22; 95% CI 1.07 to 1.38) and higher 90-day readmission odds (OR 1.27; 95% CI 1.14 to 1.42). Distinct comorbidity patterns were observed across outcomes: anaemia showed the strongest association with prolonged LOS, whereas ischaemic heart disease, chronic kidney disease, chronic obstructive pulmonary disease and valvular disease were associated with readmission. CONCLUSIONS: Multimorbidity is highly prevalent among patients hospitalised with HF in Indonesia and is associated with adverse hospitalisation outcomes. Both multimorbidity burden and specific comorbidities were associated with these outcomes, suggesting a need for health systems that better account for multimorbidity.