Perioperative Use of Methotrexate and Tumor Necrosis Factor α Inhibitors Combination Therapy Is Not Likely to Increase Post-Operative Infection Rate in the National Veterans Health Administration Administrative Databases

Objective: The aim of the study is to assess the risk of post-operative outcome in rheumatoid arthritis (RA) patients continuing versus stopping combination therapy of methotrexate (MTX) and hydroxychloroquine (HCQ) or tumor necrosis factor α inhibitors (TNF) prior to surgery. Methods: Using the United States Veterans Affairs (VA) databases, we identified surgical procedures in a 17-year cohort of RA patients. Among those patients, those on MTX + HCQ or MTX + TNF were identified. Post-operative outcome variables include infection, length of post-operative hospital stay and death. Results: We identified a total of 29,708 surgeries in RA patients. Among them, we identified the most recent elective surgeries without pre-operative infection in 16,174 patients. There were 783 and 550 patients on MTX + HCQ and MTX + TNF, respectively. The rates of post-op infection were 5% and 4% for the MTX + HCQ and MTX + TNF continuing medication groups, respectively, similar to the general RA population (5%). Sensitivity analyses at various time points of discontinuation combination therapies prior to surgery did not show significant change in terms of infection. Conclusions: The prevalence of adverse outcome is low. The proportion of post-operative infection in continuing and discontinuing medicine groups is similar for both MTX + HCQ and MTX + TNF. While we were unable to formally compare proportions of post-operative infection among the two groups, these preliminary findings do not support the hypothesis that continuing either MTX + TNF or MTX + HCQ combination during perioperative period increases post-operative infection compared with discontinuation prior to therapy.