Clotting factor product administration and same‐day occurrence of thrombotic events, as recorded in a large healthcare database during 2008–2013

Summary Background Thrombotic events (TEs) are serious adverse events that can occur following administration of clotting factors (CFs). Objectives To evaluate occurrence of same‐day TEs for different CF products and potential risk factors. Methods A retrospective cohort study of individuals exposed to CF products during 2008–2013 was conducted using a large commercial insurance database. CF products were identified by procedure codes, and TEs were ascertained via diagnosis codes. Crude same‐day TE rates (per 1000 persons exposed) were estimated overall and by congenital factor deficiency (CFD) status, CF products, age and gender. Multivariable logistic regression analyses were used to control for confounding. Laboratory analysis was used to compare the procoagulant activities of FIX products. Results Of 3801 individuals exposed to CFs, 117 (30.8 per 1000) had same‐day TEs recorded. The crude same‐day TE rate was higher for CF users without CFD, 70.2 (102 of 1452), as compared with those with CFD, 6.4 (15 of 2349) (RR, 11.0; 95% CI, 6.4–18.9). For individuals without CFD, a significantly increased same‐day TE risk was identified for factor IX complex (OR, 6.92; 95% CI, 3.11–15.40), factor VIIa (OR, 9.42; 95% CI, 4.99–17.78) and other products when compared with fibrin sealant. An increased risk of a TE was found with older age (≥ 45 years), history of TEs and underlying health conditions. The laboratory identified elevated procoagulant activity in Profilnine® and Benefix®. Conclusions The study shows an increased same‐day TE risk for CF users without CFD and suggests substantial off‐label CF use. The study findings also show elevated same‐day TE rates for different CF products and suggest the importance of product properties and patient factors.