Psychological distress, self-determination, and social capital associated with quality of life among retirees in Sarawak: a cross-sectional structural equation modelling analysis

Population aging is accelerating in middle-income countries; however, evidence on the psychosocial factors associated with later-life quality of life (QoL) remains limited in Southeast Asian settings. Psychological distress, self-determination, and social capital have each been linked to well-being in older populations, but few studies have examined these constructs together among retirees in geographically dispersed, multiethnic populations. This study examined the associations between psychological distress, self-determination, social capital, catastrophic health expenditure (CHE), and QoL among retirees in Sarawak, Malaysia.

A cross-sectional survey was conducted among 1,410 retirees aged 60 years and above across nine districts in southern, central, and northern Sarawak. QoL was measured using the WHOQOL-BREF; psychological distress using the Depression, Anxiety, and Stress Scales-21; self-determination through basic psychological need satisfaction comprising autonomy, competence, and relatedness; and social capital using bonding and bridging indicators. CHE was assessed using health-related out-of-pocket expenditure thresholds. Partial Least Squares Structural Equation Modelling with 10,000 bootstrap resamples examined direct associations, statistical mediation pathways, and moderation effects. Hierarchical multiple regression assessed incremental variance explained by sociodemographic, health-related, and psychosocial variables.

The PLS-SEM model explained 56% of the variance in QoL. Self-determination showed the strongest positive association with QoL (β = 0.546, p < .001), followed by social capital (β = 0.352, p < .001). Psychological distress was negatively associated with self-determination (β = -0.379, p < .001) and social capital (β = -0.327, p < .001). Significant indirect associations were observed between psychological distress and QoL through self-determination (β = -0.207, 95% bootstrap confidence interval [BCa] CI: -0.233, -0.181) and social capital (β = -0.115, 95% BCa CI: -0.135, -0.097). CHE showed small, non-significant main direct and indirect associations with QoL. A small CHE by social capital interaction was observed for self-determination (β = -0.06, p = .013), requiring cautious interpretation. Hierarchical regression showed that health-related variables and CHE produced a large incremental increase in explained variance across Qol domains, while psychosocial variables added a further substantial 20–30%.

In this cross-sectional sample, QoL was more strongly associated with psychological distress, self-determination, and social capital than with CHE. Self-determination appeared to be the strongest statistical pathway linking psychological distress with QoL. Healthy aging strategies may benefit from greater attention to mental health, autonomy, competence, relatedness, and social connectedness. Longitudinal studies are needed to clarify temporal relationships and causal mechanisms.