[Impact of outpatient services utilization of heart failure patients on hospitalization rate and its threshold effect: Taking patients with Urban Employee Basic Medical Insurance in Zhejiang Province as an example].

Objective: To examine the impact of outpatient service utilization on hospitalization rates in patients with heart failure, with a focus on identifying the threshold effect, and to provide evidence to support the design of outpatient medical insurance reimbursement policies for heart failure patients.

Methods: Using a stratified random sampling method, individual reimbursement data of heart failure patients covered by Urban Employee Basic Medical Insurance in Zhejiang Province from year 2013 to 2017 were extracted. A panel fixed-effects logit regression model and a threshold effect model were applied to analyze the impact of annual outpatient service utilization in the previous year on the hospitalization rate in the current year and to identify the threshold effect. The annual outpatient service utilization indicators included the annual outpatient visits, annual outpatient expenses, annual outpatient drug expenses, and annual outpatient self-expenses within the policy. Hospitalization rate indicators comprised the annual hospitalization rate, rehospitalization rate within 30 days, and rehospitalization rate within 90 days.

Results: (1) The study found that an increase in prior-year annual outpatient service utilization led to a decrease in the current-year annual hospitalization rate. However, the effects on the rehospitalization rate within 30 days and rehospitalization rate within 90 days were not statistically significant; (2) The thre-shold effect of prior-year annual outpatient service utilization on the current-year annual hospitalization rate was also identified. When the prior-year annual outpatient visits were less than or equal to the threshold (12 visits), the current-year annual hospitalization rate decreased as the prior-year annual outpatient visits increased and statistically significant, and the regression coefficient was not significant when the prior-year annual outpatient visits were higher than the threshold (12 visits). Correspondingly, the thresholds for annual outpatient expenses and annual outpatient self-expenses within policy in the previous year were 3 342.8 yuan and 736.9 yuan, respectively.

Conclusion: There is a threshold effect of prior-year annual outpatient service utilization on the current year' s annual hospitalization rate in heart failure patients. These results have important implications for designing outpatient health insurance policies for heart failure patients to improve the patients' utilization of outpatient services and decrease the hospitalization rates. Specifically, policymakers should consider the identified thresholds when designing reimbursement policies for heart failure patients, which may help to optimize the use of medical resources and reduce the burden of medical expenses.