Impact of the cost exception policy on long-term treatment interruption among pulmonary tuberculosis patients in South Korea: a nationwide population-based study

Abstract

Abstract Background Political change regarding for exemption of co-payment for tuberculosis (TB) treatment was made in July 2016. We investigated the effect of the co-payment waiver on long-term treatment interruption and clinical outcomes among pulmonary TB patients in South Korea. Methods Patients who had newly treated TB in South Korea from 2013–2019 were selected from nationwide data using the entire Korean National Health Insurance Service population. Interrupted time series analysis was used to evaluate the effect of policy implementation on treatment adherence. Moreover, mortality rates were assessed depending on the history of long-term treatment interruption. Results A total of 73,116 and 1,673 patients were included in the final study population for each drug-susceptible and drug-resistant pulmonary TB. After implementing the cost exemption policy, the long-term treatment discontinuation rates tended to decrease in the continuation phase in the drug-susceptible TB group (slope change: −0.097, P = 0.011). However, it was increased in the intensive phase in the drug-resistant TB group (slope change: 0.733, P = 0.001). Drug-resistant TB patients were likely to experience long-term discontinuation of TB treatment (adjusted odds ratio, 6.04; 95% confidence interval [CI], 5.43–6.71), and history of long-term treatment interruption was a significant risk factor for both 1-year and overall mortality rates among the study population (adjusted hazard ratios: 2.01, 95% CI, 1.86–2.18 and 1.77, 95% CI, 1.70–1.84, respectively). Conclusions Implementing the cost exemption policy effectively reduced the long-term treatment discontinuation rate among pulmonary TB patients. Because long-term treatment interruption is relevant to increasing mortalities, political change for widening the coverage helped improve treatment outcomes in TB patients.