Network analysis identifies age-specific clusters of multimorbidity, disability, social participation, and falls

Introduction: The onset and coexistence of chronic diseases during aging are associated with adverse outcomes, including disability, restriction of social participation, and falls. Although chronological age is often treated as a confounding variable in epidemiological models, evidence remains limited on how multimorbidity patterns are structured across different age groups. This study aimed to identify clusters of multimorbidity and examine their associations with disability in instrumental activities of daily living (IADL), restriction of social participation, and falls across age groups.

Methods: This cross-sectional study used data from the second wave of the Brazilian Longitudinal Study of Aging. Older adults were assessed for IADL disability, restriction of social participation, falls, and self-reported chronic diseases. Associations were estimated using Mixed Graphical Models, and clusters were identified using the Walktrap algorithm. Analyses were stratified into three age groups: 60–69 years, 70–79 years, and 80 years or older.

Results: Among adults aged 60–69 years (n = 3,461), five clusters were identified, indicating a segmented multimorbidity structure. Restriction of social participation clustered with cardiometabolic conditions and cataract, whereas IADL disability and falls grouped with depression, cancer, and macular disease. In the 70–79 year group (n = 2,296), three clusters were observed, with disability, restriction of social participation, and falls converging into a single cluster alongside cardiometabolic, respiratory, neurodegenerative diseases, and depression. Among adults aged 80 years or older (n = 1,172), three clusters were also identified. Falls clustered with cancer, respiratory diseases, depression, diabetes, and diabetic retinopathy, while IADL disability and restriction of social participation were associated with cardiometabolic and neurodegenerative diseases.

Conclusion: Network analyses revealed age-specific multimorbidity patterns and distinct associations with disability, restriction of social participation, and falls, highlighting the importance of age-sensitive healthcare strategies and public health policies tailored to heterogeneous needs across the aging population.