Does the abolition of copayment increase ambulatory care utilization?: a quasi-experimental study in Germany

Due to a problematic situation with public finances, Germany introduced a copayment scheme for ambulatory care visits in 2004. In 2012, Germany achieved a balanced budget, and copayment was abolished on the 1st of January 2013. This policy change offers a rare opportunity to explore the impact of the abolition of copayment, compared to the much more frequently studied introduction of copayment. We therefore investigate the development of ambulatory care and inpatient care utilization following this policy change among people over 50 in Germany, as well as the heterogeneous impacts among vulnerable people, such as the low-income population, the chronically ill and the elderly over the age of 65. We use data from the Survey of Health, Ageing and Retirement in Europe and adopt a difference-in-differences approach with matching. We found that the abolition of copayment only caused an increase in ambulatory care use in the shorter term, while leading to a significant reduction in the longer term. In addition, we find a negative effect on inpatient care use, i.e., the hospitalization offset effect. Finally, we demonstrate that vulnerable people were more sensitive to the abolition of copayment.