Multimorbidity among indigenous tribal communities in Kerala, India: a cross-sectional study (2022-2024).

Background: The burden of multimorbidity is increasing in India, particularly in the state of Kerala. Despite advancement in primary care, several inequities persist among underserved tribal communities. We assessed the prevalence and determinants of non-communicable disease multimorbidity among the indigenous adult (≥30 years) population belonging to tribal communities in Kerala. Methods: We conducted a community-based cross-sectional survey among 18 Indigenous tribal communities in Kerala from September 2022 to July 2024. Adults who were older than or equal to 30 years and residing in selected hamlets were included in the study. We collected sociodemographic, behavioural, clinical, and anthropometric data using standard tools. Further, we measured blood pressure, point-of-care glucose, creatinine, haemoglobin, and urine biomarkers (sodium, potassium, creatinine, albumin). Detailed medical records and clinical histories were systematically reviewed to ascertain the prevalence of non-communicable diseases (NCDs). Data analysis was conducted using descriptive statistics, multivariable regression, and disease co-occurrence network analysis (Louvain clustering) in R (version 4.4.3). Findings: A total of 2333 adults (≥30 years) belonging to tribal communities were included in the study. The mean age (±SD) of the participants was 50.0 ± 13.2 years and three-fifths (n = 1356) of them were women. Cardio-metabolic conditions, including hypertension (50.8%), diabetes (32.2%), and chronic kidney disease (22.6%), were the most common NCDs. The overall prevalence of multimorbidity was 55.2% (95% CI 52.7-57.6). The prevalence was 39.5% among adults 30-49 years and 87.3% among those older than 70 years of age. Older age group had higher odds of multimorbidity, with adjusted odds ratios (AORs) ranging from 2.4 to 8.0. Low BMI (AOR 1.8, 95% CI 1.2-2.8) and abdominal obesity (AOR 2.1, 95% CI 1.4-3.0), were also associated with multimorbidity. Network analysis revealed a dominant cardio-metabolic cluster linking hypertension, diabetes, chronic kidney disease, and anaemia. Interpretation: Multimorbidity is prevalent in one out of two adults (≥30 years) among indigenous tribal communities in Kerala. Cardiometabolic and renal diseases often co-occur. The findings underscore the need for integrated primary care, targeted screening, and culturally tailored interventions to address chronic disease burden in Indigenous population. Funding: This project is funded by the Department of Science and Technology (DST), Government of India (Project 6117).