Social Medical Insurances, Choices of Medical Institutions and the 'Siphon Effect' in the Health Service Market: Evidence from 2021 Yangtze River Delta Region of China.

ABSTRACT

Purpose: The siphon effect in the health service market is notably pronounced in many countries. How to measure and identify the determinants contributing to the siphon effect presents a substantial challenge. This study aimed to analyse the effect of two different social medical insurances, the Basic Medical Insurance System for Urban Employees (BMISUE), and the Basic Medical Insurance System for Urban and Rural Residents (BMISURR), on the siphon effect in the health services market. Methods: The data used in this study were from the 2021 Health Life Satisfaction Survey of Yangtze River Delta (HLSSYRD) conducted by Shanghai Jiao Tong University. The logistic model was used to evaluate the association between social medical insurances and individual choices of medical institutions, and the Propensity Score Matching method (PSM) was used to check the robustness of basic results. Results: Residents covered by BMISUE were more likely to choose a general hospital when they first sought medical treatment (OR = 5.377, 95% CI 4.887, 5.915) relative to those insured by BMISURR. Further analysis showed that BMISUE would accelerate the siphon effect of general hospitals, people insured by BMISUE were still more likely to choose general hospitals despite being close to primary hospitals compared to those insured by BMISURR (OR = 3.240, 95% CI 2.945, 3.565). Heterogeneity analysis indicated BMISUE had a greater impact on residents aged 15-59 years and those with high income compared to older people and individuals with low income. Conclusion: Different social medical insurances can substantially affect residents' first choice of medical institutions. BMISUE with higher benefits level could exacerbate the siphon effect in the health service market. More equitable medical security system should be strengthened to bridge the benefits gap between BMISUE and BMISURR.