P158 RISK FACTORS FOR NON-ADHERENCE TO BIOLOGIC THERAPIES IN INFLAMMATORY BOWEL DISEASE

Abstract Background Non-adherence to medications is common in patients with inflammatory bowel disease (IBD). The aim of this study was to assess adherence to biologic medications prescribed for IBD, and to identify risk factors for biologic non-adherence. Methods This was a single center retrospective cohort study involving IBD patients receiving biologic therapies. Adherence was assessed over a two-year period using a modified medication possession ratio calculation obtained from specialty pharmacy and infusion center records. Potential risk factors for non-adherence were identified in univariate fashion and then aggregated into a multivariate logistic regression model to assess independent predictors of non-adherence. Results Three hundred sixty-five patients met inclusion criteria, 82% had Crohn's disease. The pooled 24-month adherence rate to biologic therapy was 66%; adherence to individual biologics were as follows: infliximab 70%, adalimumab 57%, certolizumab pegol 50%, and vedolizumab 83%. Facility-administered biologics were associated with significantly higher adherence than self-administered biologics (OR 2.39, 95% CI 1.50 - 3.80). Additional risk factors for non-adherence included younger age (OR 0.82, 95% CI 0.68-0.99) and non-commercial insurance (OR 1.78, 95% CI 1.01 - 3.13). Patients with psychiatric disease and current tobacco had numerically higher rates of non-adherence but did not reach statistical significance. Conclusions This is the first study to assess adherence to vedolizumab in IBD patients, which was higher than three other commonly prescribed biologic medications. Certolizumab pegol adherence was low in this cohort. Self-administered injections were identified as a strong risk factor for biologic non-adherence. Younger age and non-commercial insurance were also associated with non-adherence. These patient factors and modality of administration should be considered when selecting a biologic agent for treatment of IBD.