Age specific associations and component patterns of healthy ageing using propensity score matching analysis

Abstract Background Healthy ageing encompasses maintaining optimal physical, psychological, social, and cognitive well-being across the lifespan. While age-specific needs are widely acknowledged, many studies aggregate adults of all ages, potentially overlooking life-stage-specific determinants of healthy ageing. Objectives To examine age-specific factors associated with healthy ageing and to explore the underlying components among community-dwelling adults in Hong Kong. Methods This cross-sectional baseline study, part of a 10-year longitudinal project, recruited community-dwelling adults in Hong Kong. Participants were stratified into three age groups: young (18–35 years), middle-aged (36–59 years), and older adults (60 years and above). Healthy ageing was assessed using a culturally adapted 15-item Healthy Ageing Questionnaire (HAQ). Propensity score matching (PSM) was applied to balance basic characteristics. Multiple linear regression analyses were then conducted to identify age-specific associated factors of healthy ageing scores, while principal component analysis (PCA) was employed to explore the underlying components across age groups. Results A total of 2,024 participants were included in the analysis. After balancing gender, living arrangement, education, and medical conditions through PSM, each age group comprised 232 participants. Multiple linear regressions revealed distinct age-related associations with healthy ageing. Among the young group, multimorbidity was negatively associated with healthy ageing scores, while higher education showed a strong positive association in the older group. No significant parameters were identified for the middle-aged group. PCA consistently identified HAQ-10, HAQ-14, and HAQ-15 as core components across all age groups, with social and cognitive factors becoming increasingly prominent in the older group. Conclusion Based on our age-stratified analyses, several potential directions for targeted interventions emerged. Among younger adults, associations between smoking, chronic conditions, and lower healthy ageing scores suggest that tobacco control and early chronic disease management may be relevant intervention areas. In older adults, the positive association between education and healthy ageing highlights the potential roles of health literacy and multimorbidity management support. No significant associations were observed in the middle-aged group, which may reflect unmeasured psychosocial or environmental factors, or limited statistical power. These preliminary findings suggest that adopting a life-course perspective could help inform the development of age-attuned public health strategies. However, further research is warranted to validate these associations and clarify causal relationships.