Longitudinal Association of Physical-Psychological-Cognitive Multimorbidity With Health Care Utilization and Costs Among Middle-Aged and Older People in China

Despite its prevalence, the health care burden of co-occurring physical, psychological, and cognitive (PPC) disorders remains unclear. This study examines impact of different PPC-multimorbidity patterns on health care utilization and costs among 12 643 middle-aged and older Chinese adults using longitudinal data (China Health and Retirement Longitudinal Study 2011-2020). We measured outpatient/inpatient utilization (any visit/number of visits) and out-of-pocket (OOP) costs via self-reports. Binary, count, and censored outcomes were analyzed using mixed-effects logistic, negative binomial, and Tobit regressions, respectively. Results showed that PPC-multimorbidity significantly increased outpatient/inpatient utilization and OOP costs (OR_{outpatient visit} = 1.43, IRR_{outpatient visit number} = 1.41, OR_{inpatient visit} = 1.73, IRR_{inpatient visit number} = 1.53, IRR_{hospitalization days} = 1.71, β_{outpatient costs} = 24.96, β_{inpatient costs} = 353.02; P < .001). Increasing coexisting PPC types progressively amplified health care burden (dose-response P-trend < .001). Pattern-specific analyses demonstrated heterogeneous impacts, with nearly all PPC-multimorbidity combinations elevating health care demands. In conclusion, PPC-multimorbidity imposes a substantial health care burden. These findings advance multimorbidity conceptualization beyond simple disease counts, emphasizing the need to address distinct multimorbidity patterns and their complex interactions.