George MD, et al. - This study was conducted to compare methotrexate (MTX) and tumor necrosis factor inhibitor (TNFi) persistence in spondyloarthritis vs rheumatoid arthritis (RA) and to ascertain if concomitant conventional synthetic disease-modifying antirheumatic drug (csDMARD) use is correlated with improved TNFi persistence in spondyloarthritis (SpA). Applying Optum’s deidentified Clinformatics Data Mart Database 2000–2014, researchers conducted retrospective cohort study to distinguish patients with RA, psoriatic arthritis (PsA), and ankylosing spondylitis (AS) without prior biologic use who were initiating MTX or a TNFi. Cox proportional hazards models were used to compare time to medication discontinuation over the next 2 years between patients with RA, PsA, or AS, adjusting for potential confounders. Cox models were applied to evaluate if concomitant use of csDMARD was correlated with TNFi persistence, in similar analyses stratified by disease. They distinguished 31,527 MTX initiators (26,708 RA, 2939 PsA, 1880 AS) and 34,651 TNFi initiators (24,134 RA, 6705 PsA, 3812 AS). The results demonstrate that MTX discontinuation occurs sooner in patients with PsA and AS vs RA. Nevertheless, concomitant use of MTX with a TNFi is correlated with improved TNFi persistence in all 3 diseases.