849 Risk of Reoccurrence of Perianal Fistulas in Patients With Crohn’s Disease in the United States: A Retrospective Claims Database Study

Abstract

INTRODUCTION: Perianal fistulas (PAF) in patients with Crohn’s disease (CD) are associated with morbidity and impaired quality of life. Limited data is available on the risk of PAF among patients with CD and long-term PAF relapse rates. METHODS: A retrospective cohort study on US adult patients with CD identified in an US administrative claims database (2001-2018) was conducted. Patients with PAF were identified using diagnosis or procedure codes in medical claims. A PAF episode, starting from the first PAF occurrence, was defined as consecutive PAF-related codes ≤120 days of each other. PAF reoccurrence was defined as a new PAF-related code occurring after a PAF-free period of ≥180 days (proxy for remission) following the end of the first PAF episode. Time from the 180-day PAF-free period to PAF reoccurrence was estimated using KM analyses. A similar analysis was conducted in CD patients with a PAF-free period of ≥360 days. RESULTS: 5,482 patients with a PAF-free period of ≥180 days after their first PAF episode were included (CD-PAF cohort; mean age = 43.8 years and proportion of males = 51.8%). Over a mean follow-up duration of 2.6 years, 28.8% had a PAF reoccurrence. Estimated rates of PAF reoccurrence in these CD-PAF patients were 23.7%, 32.0%, 42.1% and 47.8% at 1, 2, 5, and 10 years, respectively (Table 1). In the 12 months before first PAF occurrence, 70.8% of CD-PAF patients received non-biologic therapies: corticosteroids (46.5%), antibiotics (44.4%), aminosalicylates (5-ASA) (32.5%) and immunomodulators (IMDs)/immunosuppressants (IMs) (21.1%); 25.3% used ≥1 biologic therapy; and 19.2% had ≥1 CD-related surgery. In the 4 months after first PAF occurrence, 66.5% of CD-PAF patients received non-biologic therapies: antibiotics (39.6%), corticosteroids (30.3%), 5-ASA (27.4%) and IMDs/IMs (22.1%); 31.8% used ≥1 biologic therapy; and 47.2% had ≥1 CD-related surgery. In patients with a longer PAF-free period of ≥360 days (CD-PAF360 cohort), a numerically lower proportion had a PAF reoccurrence (20.5%) and estimated rates of reoccurrence were numerically lower at every time point (32.6% at 5 years and 39.4% at 10 years) vs the CD-PAF cohort. CONCLUSION: In this retrospective US claim database analysis, the 5-year and 10-year rates of PAF reoccurrence following PAF remission of ≥180 days were 42.1% and 47.8% among patients with CD, respectively. Patients achieving longer-term remission (≥360 days) had numerically lower rates of PAF reoccurrence.