Rationale: Current guidelines recommend that all patients undergoing treatment with a tumor necrosis factor-α antagonist should receive screening for latent tuberculosis and appropriate treatment before initiating the inhibitor. However, no well-designed study has shown the efficacy of treating these patients for latent tuberculosis.
Objectives: To compare the risk of active tuberculosis between tumor necrosis factor antagonist users who have received treatment for latent tuberculosis with those who have not.
Methods: We performed a national-level retrospective cohort study in South Korea, a country with an intermediate tuberculosis burden, by analyzing claims recorded between January 1, 2011, and December 31, 2013, in an obligatory national health insurance claims database. The primary outcome, the incidence of active tuberculosis, was measured as the occurrence of an International Statistical Classification of Diseases and Related Health Problems, 10th edition, diagnosis of tuberculosis and prescription of at least two antituberculosis drugs at least twice within 90 days.
Results: Among 10,863 eligible new tumor necrosis factor antagonist users, 2,461 (22.7%) received treatment for latent tuberculosis. The incidence rate of tuberculosis per 1,000 person-years was lower for the treated group (4.07; 95% confidence interval [CI], 1.55-6.60) than for the untreated group (12.34; 95% CI, 9.96-14.72). The risk for tuberculosis was significantly reduced by preventive chemotherapy (incidence rate ratio, 0.33; 95% CI, 0.17-0.63).
Conclusions: Treatment for latent tuberculosis was highly effective in preventing the development of tuberculosis among tumor necrosis factor antagonist users.
Keywords: immunocompromised host; latent tuberculosis; tumor necrosis factor-α.