Do Reduced Copayments Affect Mortality after Surgery due to Stroke? An Interrupted Time Series Analysis of a National Cohort Sampled in 2003-2012

Background: The South Korean government introduced a policy in 2 phases, in September 2005 and in January 2010, for reducing copayments for patients with critical diseases, including stroke, to prevent excessive medical expenditures and to ease economic barriers. Previous studies of the effect of this policy were focused primarily on cancer. Therefore, we investigated the relationship between this policy and 1-year mortality after surgery among patients with stroke. Methods: We used data from the Korean National Health Insurance sampling cohort (n = 2173 in 2003-2012) and performed an interrupted time series analysis. Results: Approximately 26% of the patients died within 1 year after surgery. The time trends after reducing copayments from 10% to 5% (phase 2) were inversely associated with risk of 1-year mortality (relative risk =.855, 95% confidence interval:.749-.975; P =.0196). In addition, this inverse association was greater in patients with low incomes, of older ages, and with higher Charlson comorbidity indices. Conclusions: The introduction of a policy for reducing copayments to ease excessive cost burdens for patients with stroke was positively associated with a reduced risk of 1-year mortality after surgical treatment due to stroke. On the basis of our results, health policy makers should make an effort to identify vulnerable populations and to overcome economic barriers for providing effective alternatives to ensure patients receive optimal health care.