Abstract
INTRODUCTION: Patients' adherence to and persistence on treatment for inflammatory bowel disease (IBD) can vary, depending on type and distribution of disease and treatment modality. We aim to identify differences in adherence and persistence with treatments with different administration routes (intravenous vs oral) in IBD. METHODS: A retrospective cohort analysis of a claims database of adult patients diagnosed with IBD or rheumatoid arthritis (RA) who began treatment with vedolizumab, tofacitinib, or infliximab from January 2015 through December 2015. Adherence evaluated by proportion of days covered (PDC) and cumulative days with gaps at least 20% beyond expected interval (CG20) using multivariable generalized linear equation models. Persistence assessed as time to treatment discontinuation over 12 months of follow-up using Kaplan-Meier estimates and Cox proportional hazards models; proportion of persistent patients determined via multivariable logistic regression. Indirect comparisons across disease states adjusted using infliximab data. RESULTS: After indirect adjustment by disease, mean PDC difference was significantly higher (difference of 4.7%; P = 0.0376) and mean CG20 was lower (difference of 15 days; P = 0.0646) but not statistically significant in vedolizumab/IBD than tofacitinib/RA. CONCLUSION: We describe a novel adjustment method for interdisease treatment differences using infliximab treatment patterns to bridge differences between IBD and RA. After adjustment, adherence was higher with infusions than oral medications, which may affect outcomes. Indirect comparisons between vedolizumab and tofacitinib are not generalizable and should be confirmed in tofacitinib-treated IBD patients. FUNDING: Takeda Pharmaceuticals U.S.A., Inc.