To examine treatment patterns, dosing, health care resource utilization, and cost of tumor necrosis factor inhibitors (TNFi), adalimumab (ADA) and infliximab (IFX), among patients enrolled in US Humana insurance plans who have been diagnosed with ulcerative colitis (UC).
This retrospective cohort study identified the first pharmacy or medical claim for ADA or IFX (from January 1, 2007, to December 31, 2014) in patients with continuous enrollment for 6 months or more preindex and 12 months or more postindex, with one or more UC diagnosis claim 6 months pre- or postindex. TNFi discontinuation was defined as a therapy gap of 56 days or more for ADA and 112 days or more for IFX. TNFi switch was defined as nonindex TNFi initiation. Health care resource utilization and costs were characterized quarterly according to treatment patterns.
The study population comprised 295 patients: mean age 50.9 years, 50.5% females, and 61.7% in southern United States. At the index date, 17% of patients received ADA and 83% received IFX. Treatment discontinuation was observed in 52% of ADA and 45% of IFX users through 12 months postindex (mean time 19 and 22 weeks, respectively). Among discontinuers, 46% of ADA and 68% of IFX users did not restart/switch TNFi. ADA and IFX showed mean times to switch of 18 and 30 weeks, respectively. TNFi discontinuers had the lowest mean quarterly total health care cost ($3,935) versus patients who initiated/switched TNFi ($15,004). Nevertheless, discontinuers had higher UC-related hospitalization versus patients receiving therapy.
Approximately half of ADA and IFX users discontinued, with approximately half of discontinuers not restarting/switching therapies. Further investigation of treatment patterns and outcomes after TNFi discontinuation is required.