Epidemiology of multimorbidity among indigenous adults: Insights from a large-scale population survey of 53 different indigenous groups in East India.

Purpose: Indigenous populations in India face a growing burden of multimorbidity, yet data on its prevalence and patterns remain scarce. This study estimated the prevalence, determinants, and co-occurrence of multimorbidity among Indigenous adults using data from the Odisha Tribal Family Health Survey (OTFHS). Methods: The analysis included 19,430 adults (≥18 years) from 9711 households across 14 districts, representing 53 Indigenous groups, including 13 Particularly Vulnerable Tribal Groups (PVTGs). Multimorbidity-defined as having ≥2 chronic conditions-was assessed through self-reports and laboratory results. Prevalence estimates used descriptive statistics; associated factors were identified via ordinal logistic regression, and co-occurrence patterns of chronic conditions were visualized using a matrix-based plot that displays the frequency and overlap of conditions (UpSet plot). Results: The weighted prevalence of multimorbidity was 21.7 % (95 % CI: 20.5 %, 22.9 %), increasing from 3.8 % in those aged 18-25 to 48.2 % in those 60 and older. Regression analysis showed that older age, male sex, and tobacco and alcohol use were significantly associated with higher odds of multimorbidity. Hypertension was the most prevalent condition, often co-occurring with kidney disease, liver disease, or back pain. Conclusion: These findings highlight the urgent need for age- and sex-sensitive, integrated health interventions tailored to Indigenous communities.