Assessing adherence to infusion-based biologic therapies in patients with inflammatory bowel disease

Res Social Adm Pharm. 2021 Aug;17(8):1420-1425. doi: 10.1016/j.sapharm.2020.10.011.Epub 2020 Oct 22.

Geoffrey S Haar 1, Abhinav Vasudevan 2, Colin M Curtain 3, Daniel R van Langenberg 2


Author information

  • 1Department of Pharmacy, Eastern Health, Melbourne, VIC, Australia. 
  • 2Department of Gastroenterology, Eastern Health, Melbourne, VIC, Australia; Eastern Health Clinical School, Monash University, Melbourne, VIC, Australia.
  • 3School of Pharmacy and Pharmacology, University of Tasmania, TAS, Australia.


Background: The intravenous biologics infliximab and vedolizumab are effective long-term therapies for inflammatory bowel disease (IBD). Though highly effective, suboptimal adherence may result in loss of response and adverse sequelae. The extent and outcomes of suboptimal adherence with intravenous biologics, including in IBD, requires further evaluation.

Objectives: To ascertain adherence to infliximab and vedolizumab infusions, and determine factors associated with poorer adherence within an IBD cohort.

Methods: A retrospective single-centre cohort study of IBD patients, assessing adherence to infliximab and vedolizumab over 2 years (July 1, 2017 to June 30, 2019) was conducted. Medical and pharmacy dispensing records were used to determine date of infusion. Adherence was assessed using the continuous, multiple interval measure of medication gaps (CMG). Objectively measured disease remission was achieved if one or more of endoscopic remission, faecal calprotectin <100 μg/mL and/or CRP <5 mg/mL occurred within 3 months of end of follow-up. Bivariate analysis and multiple linear regression elucidated factors associated with poorer adherence.

Results: Of 193 IBD patients, 132 (68.4%) had Crohn's disease. One hundred and thirty six (70.5%) patients received infliximab and 57 (29.5%) received vedolizumab with a median 13 [IQR 11-14] doses administered per patient over 2 years. Adherence according to CMG was similar between infliximab and vedolizumab groups (median 1.5% vs 1.2%, p = 0.31). In multiple linear regression analysis male sex, shorter IBD duration and clinic non-attendances were each associated with poorer adherence (Beta 4.69, 3.90, 3.56 respectively, p < 0.05) and objective disease remission was inversely associated with poorer adherence (Beta -3.27, p < 0.05).

Conclusion: There was a wide range of adherence to biologic infusions in this IBD cohort with poorer adherence associated with patient related factors. Conversely, objectively measured remission was strongly associated with adherence. This emphasises the need for targeted interventions to improve adherence and monitoring, and mitigate treatment delays.

© Copyright 2013-2024 GI Health Foundation. All rights reserved.
This site is maintained as an educational resource for US healthcare providers only. Use of this website is governed by the GIHF terms of use and privacy statement.