OBJECTIVES: In China, the proportion of outpatient visits at tertiary hospitals has been increasing, while the proportion of outpatient visits at primary health facilities has been decreasing in recent years. Moreover, the inpatient rate in China is also higher compared to other OECD member countries. This study aimed to examine how the Medical Insurance Outpatient Pooling (MIOP) policy on outpatient services affected the utilization of medical services by the insured.

METHODS: We obtained data from the China Health and Retirement Longitudinal Study (CHARLS) 2018 and integrated it with the MIOP policies across 102 cities in China as of 2018. The two-part model (2 PM) was used to explore the impact on the utilization of medical services, and the instrumental variable method (IV-2SLS) was used to deal with endogenous problems.

RESULTS: By controlling the other factors of personal and urban medical resources, after the implementation of the MIOP policy, the outpatient rate and self-payment expenses for outpatient services increased by 15.7% (P<0.001) and 49.9% (P<0.001) respectively and decreased the overall self-payment expenses mainly including outpatient services, inpatient services, pharmaceutical services, and self-diagnosis by 12.5% (P<0.001). The mechanism test revealed that there was a substitution relationship between the demand for inpatient and outpatient services (rho=-0.146, p<0.001). Subsample analysis revealed heterogeneity between urban and rural residents, as well as individuals aged above and below 60. Additionally, When the MIOP policy in some pilot cities didn't have a deductible or ceiling, and had a higher reimbursement percentage, it provided further help to the insured.

CONCLUSIONS: The MIOP policy has significantly increased the utilization of outpatient services. Moreover, it plays a role in reducing insurers' burden of medical expenses. To refine fund pooling for outpatient services, the deductible should be eliminated, the ceiling should be raised, and the quality of primary health facility services should be improved.