Prevalence and associated factors of incident and persistent loneliness among middle-aged and older adults in Thailand

Background: The aim of the study was to assess the prevalence and associated factors of incident and persistent loneliness in a prospective cohort study among middle-aged and older adults (≥ 45 years) in Thailand. Methods: Longitudinal data from the Health, Aging, and Retirement in Thailand (HART) study in 2015 and 2017 were analysed. Loneliness was assessed with one item from the Center for Epidemiological Studies Depression scale. Logistic regression was used to calculate predictors of incident and persistent loneliness. Results: In total, at baseline 21.7% had loneliness, 633 of 3696 participants without loneliness in 2015 had incident loneliness in 2017 (22.2%), and 239 of 790 adults had persistent loneliness (in both 2015 and 2017) (30.3%). In adjusted logistic regression analysis, low income (aOR: 1.27, 95% CI: 1.03 to 1.57), poor self-rated physical health status (aOR: 1.64, 95% CI: 1.27 to 2.12), hypertension (aOR: 1.34, 95% CI: 1.09 to 1.65), depressive symptoms (aOR: 1.97, 95% CI: 1.11 to 3.49), and having three or chronic conditions (aOR: 1.76, 95% CI: 1.19 to 2.60) were positively associated and a higher education (aOR: 0.74, 95% CI: 0.55 to 0.98) and living in the southern region of Thailand (aOR: 0.43, 95% CI: 0.30 to 0.61) were inversely associated with incident loneliness. Poor self-rated physical health status (aOR: 1.91, 95% CI: 1.26 to 2.88), and having three or more chronic diseases (aOR: 1.78, 95% CI: 1.07 to 2.98), were positively associated, and living in the southern region (aOR: 0.40, 95% CI: 0.25 to 0.65) was inversely associated with persistent loneliness. Conclusion: More than one in five ageing adults had incident loneliness in 2 years of follow-up. The prevalence of incident and/or persistent loneliness was higher in people with a lower socioeconomic status, residing in the central region, poor self-rated physical health status, depressive symptoms, hypertension, and a higher number of chronic diseases.