Nine-to twelve-month anti-tuberculosis treatment is associated with a lower recurrence rate than 6-9-month treatment in human immunodeficiency virus-infected patients: A retrospective population-based cohort study in Taiwan

Background Human immunodeficiency virus (HIV)-infected patients are at an increased risk of tuberculosis (TB) and its recurrence following completion of anti-TB treatment. We investigated whether extending anti-TB treatment to 9 months or longer reduces TB recurrence. Methods HIV-infected patients who were diagnosed with pulmonary TB between 1997 and 2009 and who received anti-TB treatment for a duration between 5.5 and 12.5 months were identified from the National Health Insurance Research Database in Taiwan. Those who received any non-fluoroquinolone second-line anti-TB drug for >28 days were excluded. Factors associated with TB recurrence within 2 years after completion of anti-TB treatment were explored using Cox regression analysis. Sensitivity analysis was performed for a subpopulation fulfilling strict diagnostic criteria for HIV infection. Results TB recurrence was observed in 18 (3.5%) of 508 HIV-infected patients. The recurrence rate declined from 5.4% to 1.0% after the implementation of directly observed therapy, short course (DOTS) in 2006 (p = 0.014). The recurrence rate was 5.9%, 5.2%, and 1.6% in patients who received anti-TB treatment for <195, 195-270, and >270 days, respectively(p = 0.066). Cox regression analysis revealed that TB diagnosed in the DOTS era (hazard ratio [HR]: 0.18 [0.04-0.77]) and anti-TB treatment for >270 days (HR: 0.24 [0.06-0.89]) were associated with a reduced risk of TB recurrence. Sensitivity analysis of 449 selected patients revealed that anti-TB treatment for >270 days was a significant factor. Conclusion In Taiwan, the 2-year TB recurrence rate in HIV-infected patients declined after implementation of DOTS. The risk of TB recurrence in HIV-infected patients can be further reduced by extending anti-TB treatment to 9-12.5 months.