Effect of a medical subsidy on health service utilization among schoolchildren: A community-based natural experiment in Japan

Reducing out-of-pocket medical payments for children can reduce financial barriers to healthcare, but may increase health service expenditure. Efficient schemes of patient cost-sharing are needed to address this. We explored the impacts of a medical subsidy for children (MSC), which contained two schemes for cost-sharing of medical expenditure and health service utilization. The first is a monthly stop-loss policy, or caps on out-of-pocket payments, for outpatient/inpatient services; this reduces out-of-pocket payments for those who use greater amounts of health services. The second is a free prescription policy, which eliminates out-of-pocket payments regardless of the amount of drug expenditure. Expansion of the MSC was used as a natural experiment in a Japanese prefecture. We analyzed Japanese National Health Insurance claims data covering April 2013 to January 2017, and found no significant effect of the stop-loss policy on outpatient/inpatient service expenditures, regardless of the children’s baseline health status. The free prescription policy, however, significantly increased prescription drug expenditure to 116% in the total sample and 121% among children with good health status, but not among children with poor health status. Increased health expenditure among healthy, low-volume users was found to cause increased overall expenditure. The stop-loss policy for children is potentially efficient because it selectively reduced out-of-pocket payments in high-volume users and did not increase overall expenditure.