Clinical impact of the coronavirus disease 2019 pandemic on the quality of pulmonary tuberculosis management with national reimbursement data in Korea: a retrospective cohort study

Backgrounds: The coronavirus disease 2019 (COVID-19) pandemic has retreated the years of progress that essential tuberculosis (TB) medical services provided in reducing the burden of TB. This study evaluated the clinical impact of the COVID-19 pandemic on TB management based on treatment discontinuation and mortality rates. Methods: Two time intervals were included in this study: before the spread of COVID-19 (2018–2019) and during the pandemic phase of COVID-19 (2020–2021). Newly diagnosed patients with pulmonary TB (42,930 before and 32,094 during COVID-19) were included using the national reimbursement data from the health insurance service in Korea. Treatment discontinuation was defined as the discontinuation of treatment for more than 2 weeks during the initial intensive care phase or for more than 2 months during the maintenance phase. Mortality rates were compared before the spread and during the pandemic phase of COVID-19 in all patients and subgroups with various comorbidities. The Kaplan–Meier survival curve for each group of study participants was derived, and collective statistical significance was confirmed using the log-rank test. Results: The treatment discontinuation rate over the entire period showed a trend of decreasing the time factor (-0.0084), decreasing the level change (-0.0166), and increasing the intersection term (0.0039). These tendencies were similar during the initial intensive care and maintenance treatment periods, suggesting that the decreasing trend over time was significant, but the level change and slope change before the spread and during the pandemic phase of COVID-19 were not in agreement. The total mortality rates increased more during the COVID-19 pandemic (14.6% increase after 1 year and 18.9% increase after 2 years, based on 2020) than before COVID-19 (12.3% increase after 1 year and 16.1% increase after 2 years, based on 2018). Regarding the impact of comorbidities on TB mortality, malnutrition and diabetes showed a strong impact on the mortality with more than 2 of relative risks both in 1-year and 2-year mortalities. Conclusion: This study verified the clinical impact of the COVID-19 pandemic on TB management. Therefore, establishing appropriate TB management policies is urgently needed for the future COVID-19-like pandemic situation.