Association between reduction in copayment and gastric cancer patient concentration to the capital area in South Korea: NHI cohort 2003–2013

Since 2004, the South Korean government has introduced a policy that decreases copayment for cancer patients by strengthening public coverage in the National Health Insurance (NHI) system (first phase=copayment for outpatient care from 30% to 20%; second phase=copayment for total medical expenditures from 20% to 10%; third phase=copayment for total medical expenditures from 10% to 5%). We aimed to investigate the relationship between the policy introduction and patient visits to hospitals in the capital area. We used data from the NHI Cohort 2003–2013, which included all medical claims (7193 cases) filed for 2124 patients who visited the hospital due to stomach cancer, and performed a segmented Poisson regression analysis. Of all hospital visits, 40.6% of patients were from the capital area. After the introduction of the second phase of the policy, there was an increase in patient concentration in the capital area, although there were no significant effects on patient concentration during the first and third phases of the policy. In conclusion, our findings suggest that the introduction of a policy that reduces copayment for cancer patients had a substantial impact on patient concentration in the capital area. Therefore, health policymakers should consider effective alternatives including efficient allocation of medical resources or support for the more vulnerable population as flexible benefit plans to aid healthcare utilization by cancer patients.