Time to appropriate treatment in patients with multidrug-resistant tuberculosis in South Korea: Are we still in 2010?

Background
This study investigated the time to appropriate treatment and factors affecting late treatment initiation in patients with multidrug-resistant tuberculosis (MDR-TB) in South Korea.
Methods
Data from patients with culture-confirmed pulmonary MDR-TB who received treatment at Pusan National University Hospital (PNUH) between January 2010 and July 2018 were reviewed retrospectively. Patients were divided into two groups according to the first institution they visited [patients who were transferred to PNUH after diagnosis of MDR-TB (Group A) and patients who were initially diagnosed with TB at PNUH (Group B)].
Results
A total of 100 patients were included (53 in Group A and 47 in Group B). The percentage of patients in whom line probe assays (LPAs) for isoniazid and rifampin or Xpert MTB/RIF assays were performed was higher in Group B than in Group A [20.8 vs. 57.4% (P < 0.001) and 17.0 vs. 46.8% (P = 0.001), respectively]. The median time from the first visit to appropriate treatment initiation was longer in Group A (102.0 vs. 77.0 days, P = 0.002). However, a subgroup analysis of patients with pre-extensively or extensively drug-resistant TB (pre-XDR- or XDR-TB) revealed that the time to appropriate treatment did not differ between Groups A and B. Although the time to appropriate treatment decreased during the study period in both Groups A and B, this trend was not evident in patients with pre-XDR- or XDR-TB in Group B. Based on multivariate analyses, performance of LPAs for isoniazid and rifampin, performance of Xpert MTB/RIF assays, and the presence of uncomplicated MDR-TB were protective against delays in appropriate treatment initiation.
Conclusions
The time to appropriate treatment in patients with MDR-TB in South Korea was not acceptable, particularly for patients diagnosed outside of PNUH and for patients with pre-XDR- or XDR-TB. The use of rapid molecular drug susceptibility tests in various healthcare settings and introduction of second-line LPAs are required.