# Effect of Cost-Exemption Policy on Treatment Interruption in Patients With Newly Diagnosed Pulmonary Tuberculosis in South Korea

## TL;DR

A cost-exemption policy in South Korea reduced treatment interruptions for drug-susceptible tuberculosis but had mixed effects for drug-resistant cases.

## Contribution

This study evaluates the impact of a cost-exemption policy on TB treatment adherence and mortality in South Korea.

## Key findings

- The policy reduced treatment interruption in the continuation phase for drug-susceptible TB patients.
- Treatment interruption was a significant risk factor for higher mortality in drug-susceptible TB patients.
- The policy increased treatment interruption in the intensive phase for multidrug-resistant TB patients.

## Abstract

In 2021, South Korea had the highest incidence rate (49 per 100 000 population) and the third highest mortality rate (3.8 per 100 000 population) due to pulmonary tuberculosis (TB) among Organization for Economic Co-operation and Development countries. Notably, premature interruption of TB treatment interferes with TB control efforts. Therefore, we examined the effect of the co-payment waiver on treatment interruption and mortality among patients with pulmonary TB in South Korea.

Patients who had newly treated TB in South Korea from 2013 to 2019 were selected from the nationwide data of the entire Korean National Health Insurance Service (NHIS) population. The effects of policy implementation on treatment adherence and mortality rates depending on treatment interruption history were evaluated.

In total, 73 116 and 1673 patients with drug-susceptible (DS) and multidrug-resistant (MDR) pulmonary TB, respectively, were included in the final study population. After implementing the cost-exemption policy, the treatment interruption rate tended to decrease in the continuation phase in the DS-TB group (slope change: −0.097, P=.011). However, it increased in the intensive phase in the MDR-TB group (slope change: 0.733, P=.001). MDR-TB patients were likely to experience an interruption of TB treatment (adjusted odds ratio [aOR], 6.04; 95% CI, 5.43–6.71), and treatment interruption history was a significant risk factor for 1-year and overall mortality rates (adjusted hazard ratios [aHRs]: 2.01, 95% CI, 1.86–2.18 and 1.77, 95% CI, 1.70–1.84, respectively) in the DS-TB group.

Implementing the cost-exemption policy effectively reduced the treatment interruption rate among patients with DS pulmonary TB.