The role of self-efficacy and medication adherence in linking personality traits to health-related quality of life in middle-aged and older patients with chronic diseases

Improving the health-related quality of life of individuals with chronic diseases is a key goal in chronic disease management. However, limited research has examined how personality traits influence health-related quality of life in this population. This study aimed to develop a unified model to investigate the mediating roles of self-efficacy and medication adherence in the relationship between personality traits and health-related quality of life among middle-aged and older adults with chronic diseases. Data were obtained from the 2021 Psychology and Behavior Investigation of Chinese Residents (PBICR), a multi-center, cross-sectional survey conducted in 120 cities across 22 provinces in China. The final analytic sample included 1,037 patients aged 45 and older who had been diagnosed with chronic diseases and were on medication. Standardized instruments were used to measure Big Five personality traits (10-item Big Five Inventory, BFI-10), self-efficacy (General Self-Efficacy Scale, GSES), medication adherence (Medication Adherence Report Scale, MARS), and health-related quality of life (EuroQol 5-Dimension 5-Level questionnaire, EQ-5D-5 L). Structural equation modeling (SEM) was used to test the serial mediating roles of self-efficacy and medication adherence in the association between personality traits and health-related quality of life. The findings indicated that several personality traits, particularly Conscientiousness, Extraversion, and Neuroticism, were significantly associated with health-related quality of life. Self-efficacy and medication adherence sequentially mediated the relationship between personality traits and health-related quality of life. The proposed structural equation modeling showed good model fit (CFI = 0.996; RMSEA = 0.002), and the indirect effects were statistically significant based on bootstrapping results. This study advances understanding of the associations between personality traits and health-related quality of life in chronically ill middle-aged and older adults. By identifying self-efficacy and medication adherence as sequential mediators, the findings offer theoretical and practical insights for designing personalized behavioral interventions to improve health-related quality of life in this population.