Objectives: To quantify the incidence of tuberculosis (TB) in rheumatoid arthritis patients undergoing treatment with tumour necrosis factor-alpha inhibitors (TNFi).
Design: In a retrospective cohort study conducted using data from Taiwan's National Health Insurance claims databases, rheumatoid arthritis patients notified during the period 2006-2008 were recruited and classified based on types of TNFi treatment received. Active TB was the primary outcome. TB risk was estimated using Cox's proportional hazard model. The TB screening rate within 30 days of initiating treatment with TNFi was examined.
Results: Respectively 5079 and 829 patients were included in the non-TNFi and TNFi groups. Active TB rates were respectively 1411.3 and 679.5 events per 100,000 person-years in patients treated with adalimumab and etanercept. Significant TB risk was noted in patients treated with TNFi (aHR 4.87, 95%CI 2.14-11.06). No significant difference in active TB was observed between the TNFi subgroups (etanercept as reference, aHR 1.89, 95%CI 0.40-6.04). Only 8.7% (n = 9) of TNFi users underwent screening for TB before the first dose of TNFi.
Conclusions: Patients on TNFi have a significantly greater risk of active TB than non-TNFi patients in the Taiwanese population. No difference in TB risk between the two available TNFi groups was noted. Screening for TB before initiating treatment with TNFi should be implemented.