Data from the British Society for Rheumatology Biologics Register (BSRBR), a national prospective observational study comparing rates of tuberculosis in more than 10,000 patients treated with a TNF inhibitor, reported crude IRs of ~ 1.4/1000 p-y [38], while a retrospective cohort study from Taiwan (n = 951) reported IRs of tuberculosis of 0.9 and 1.1 per 1000 p-y in patients treated with etanercept and adalimumab, respectively [33]. Here, TNF is linked to tuberculosis.