Fig. 1

Flowchart of patient selection. Patients with rheumatoid arthritis (RA) who started tumor necrosis factor (TNF) inhibitors or tocilizumab between December 2013 and April 2018 were selected from a nationwide database maintained by the Health Insurance Review and Assessment service. According to the exclusion criteria, 6099 patients were selected for the analysis (the incidence of tuberculosis [TB] in these patients including switchers are presented in the Supplement). To avoid the unclear association between biologic agents and TB in patients who switched biologic drugs, we analyzed the incidence of TB in patients who were treated with only one type of TNF inhibitor or tocilizumab during the follow-up. Further, patients who developed TB at > 3 months after stopping the biologic drug were excluded from the analysis because TB was considered to be irrelevant to biologic therapy in these patients. A total of 4736 patients with RA were included for the final analysis RA, rheumatoid arthritis; TNF, tumor necrosis factor; TB, tuberculosis; LTBI, latent tuberculosis infection