Reciprocal Intergenerational Support Trajectories and All-Cause Mortality Among Middle-Aged and Older Adults in China: Evidence From a Joint-Trajectory IPCW-Cox Analysis

BACKGROUND: Intergenerational support plays an important role in health among middle-aged and older adults in China, yet the associations between dynamic multidimensional support patterns and mortality remain unclear. METHODS: Using data from the China Health and Retirement Longitudinal Study (CHARLS, 2011-2018), we applied group-based multi-trajectory modeling to identify longitudinal patterns of intergenerational support among adults aged 45-85 years. Six domains of support were jointly modeled, including financial exchange, caregiving, and social contact. Associations with all-cause mortality were examined using Cox proportional hazards models with inverse probability of censoring weighting (IPCW). Pairwise comparisons and subgroup analyses were additionally conducted. RESULTS: Five distinct intergenerational support trajectories were identified: low-contact financial exchange (29.2%), rising reciprocity (21.3%), financially intensive with declining contact (16.8%), high-intensity reciprocal (22.9%), and upward-support with high contact (9.8%). Compared with the low-contact financial exchange trajectory, all active support trajectories were associated with lower mortality risk in fully adjusted IPCW-weighted models, including rising reciprocity (HR=0.48; 95% CI: 0.39-0.60), high-intensity reciprocal (HR=0.59; 95% CI: 0.49-0.71), financially intensive with declining contact (HR=0.61; 95% CI: 0.49-0.76), and upward-support with high contact (HR=0.76; 95% CI: 0.62-0.95). Pairwise comparisons showed no significant mortality differences among the reciprocal support trajectories. Associations were generally consistent across subgroups, although significant interaction by educational attainment was observed. CONCLUSIONS: Multidimensional intergenerational support trajectories were associated with all-cause mortality among middle-aged and older Chinese adults. Reciprocal support patterns characterized by balanced financial exchange, caregiving, and social contact were associated with lower mortality risk than weak or predominantly one-directional support patterns.