Transitioning patients from intravenous to subcutaneous infliximab and vedolizumab for inflammatory bowel disease: what is the opportunity cost of improving access to healthcare?

Abstract

Biologic drugs are highly effective for inflammatory bowel disease (IBD) management but are key drivers of costs of care especially when administered intravenously (i.v.). Availability of subcutaneous (SC) formulations has increased convenience for patients and improved access to care, but at the cost of revenue to health services. To evaluate the economic impact of transitioning a tertiary centre IBD cohort from i.v. to SC biologic administration and assess the implications for key stakeholders. A retrospective analysis of all patients who received i.v. infliximab or vedolizumab in the outpatient infusion centre of a tertiary IBD centre between July 2019 and June 2021 was undertaken. Data were collated from electronic medical records, pharmacy dispensing systems and the hospital business intelligence unit. An economic analysis and theoretical financial/capacity impact analysis of a transition to an SC model were estimated under two scenarios using a random 10% and 30% of the patient cohort. Transitioning our IBD cohort from i.v. to SC administration would result in a loss to our health service of AU$2 732 123.75, composed of AU$1 463 003.75 in Weighted Inlier Equivalent Separation (WIES) and AU$1 269 120 in drug procurement revenue. However, it would ease capacity in the infusion centre by up to 5256 h. Transitioning patients to SC administration results in improved access to infusion centres and substantial savings to state governments; however, switching results in a loss of i.v. biologic-generated WIES to health services. Alternative funding models are required to achieve sustainability in IBD care and reduce reliance on i.v. biologic-generated income.