Incident multimorbidity and associated factors among middle-aged and older adults in Thailand

Assessing the longitudinal relationship between sociodemographic, lifestyle, and psychological characteristics and incident multimorbidity (IMM) in middle-aged and older persons in Thailand was the goal of this study. We examined prospective cohort data of individuals aged 45 and over from three successive waves of the Health, Aging and Retirement in Thailand (HART) research conducted in 2015, 2017, and 2020 (analytic sample N = 2442). IMM was assessed with 10 health care provider diagnosed medical conditions. To assess the longitudinal associations between measures of sociodemographic, lifestyle and psychosocial factors, and IMM between 2015 (baseline without MM), 2017 (first follow-up, IMM) and 2020 (second follow-up, IMM), we conducted Generalized Estimating Equations analysis (GEE). The 5-year cumulative IMM was 19.6% and the incidence rate was 39.1 per 1000 person-years. In the final GEE logistic regression model, sociodemographic factors (older age, urban residence, lower economic status, and central region), lifestyle factors (past alcohol use, overweight and obesity) and psychosocial factors (poor self-rated mental health, insomnia symptoms, loneliness, and low informal social engagement) were associated with IMM. We found that sociodemographic, factors and psychosocial factors were associated with IMM. Enhancing lifestyles related to reducing bodyweight, screening and treatment of poor mental health and improving social interaction may reduce MM in Thailand.