Effects of Copayment in Long-Term Care Insurance on Long-Term Care and Medical Care Expenditure

This study aimed to clarify the difference in (1) long-term care (LTC) usage and expenditure and (2) medical care service usage and expenditure before and after the change in the copayment limit for qualifying individuals from 10% to 20%. This quasi-experimental longitudinal design used the database from 1 prefecture of Japan that included 570,434 person-month records of 23,879 insured individuals (in August 2014) who used LTC services between August 2014 and July 2015 and were aged 65 years and older on August 1, 2014. We conducted difference-in-difference estimations to compare “before” and “after” outcome differences between insured individuals whose LTC copayment increased to 20% and those whose copayment remained at 10%. Sex, age, Care Needs Level, subsidy, and public assistance were adjusted in the models, along with robustness checks. Differences in both insurer's payment and insured's copayment indicated statistical significance between those whose copayment increased and those whose copayment did not increase. We found no significant difference in the number of minutes of home care service use, days of facility care service use, and LTC expenditures among those with copayment increases as well as those with no increase in copayment following the insured's copayment increase policy implementation. In contrast, the policy implementation caused significant differences in the number of days of hospitalization, medical care expenditures, and total expenditures. The increase in insured individuals' copayment decreased LTC insurer's payment. However, total LTC expenditure increased over time although the increase trend slowed down in the treatment group after the copayment increase policy implemented. Besides, medical care expenditure increased consistently among insured individuals whose copayment increased. As there appears to be a “balloon effect” between LTC and medical care services, it is important to discuss the medical care system while considering the LTC insurance system comprehensively.