P097 FISTULIZING CROHN'S DISEASE PREVALENCE ESTIMATE IN THE UNITED STATES: A SYSTEMATIC LITERATURE REVIEW AND POPULATION-BASED DATABASE ANALYSIS. (7th February 2019)

• Record Type: Journal Article
• Authors: Schwartz, David A; Tagarro, Ignacio; Diez, Mary Carmen; Sandborn, William J
• Is Part Of: Inflammatory bowel diseases. Volume 25(2019)Supplement 1
• Page Start: S46
• Page End: S46
• Publication Date: 2019-02-07
• Subjects: Inflammatory bowel diseases -- Periodicals; Colitis, Ulcerative -- Periodicals; Crohn Disease -- Periodicals; Inflammatory Bowel Diseases -- Periodicals; 616.344
• DOI: 10.1093/ibd/izy393.105
• Languages: English
• ISSNs: 1078-0998

Abstract

Abstract: Background: Intestinal fistulas may arise as a complication of Crohn's disease. They are classified according to their anatomic location as anal, rectovaginal, enterocutaneous or internal. Despite the substantial burden imposed on patients and clinicians, limited data are available on the epidemiology of fistulizing Crohn's disease in the United States. Methods: We performed a systematic literature review to ascertain the prevalence of fistulas in patients with Crohn's disease. Retrieved titles and abstracts were screened for inclusion criteria (population-based studies published between 1970 and 2017, reporting data on the epidemiology of fistulizing Crohn's disease in the United States). From identified data, the prevalence of the condition was estimated. To validate the literature-based estimate, we analysed data from a United States claims database (Truven MarketScan database) with a broad geographic coverage (national, regional, state, intrastate) that contained healthcare data for more than 60 million unique patients. A sensitivity analysis was conducted to estimate an upper limit for the prevalence of fistulizing Crohn's disease in the United States. For this analysis, the prevalence of Crohn's disease in the United States was estimated extrapolating that reported in a high prevalence area (Olmsted County, Minnesota) to the 2017 United States population. Results: The literature search retrieved seven articles for full-text review; one met the criteria for inclusion. This was a study published in 2002, that reported the cumulative incidence of fistulas in a Crohn's disease population from Olmsted County (Minnesota), over 20 years. Analysis of reported data yielded an estimated prevalence of 76, 600 patients with fistulizing Crohn's disease in the United States. Analysis of claims data from the United States healthcare database resulted in an estimated prevalence of 75, 700 patients, confirming the robustness of the original estimate. The sensitivity analysis suggested an upper limit for the prevalence of fistulizing Crohn's disease in the United States of 105, 000 patients. Conclusions: The estimated prevalence of fistulizing Crohn's disease, based on two separate analyses using different estimation methods, is approximately 77, 000 patients. According to the threshold criterion of <200, 000 patients established by the United States Food and Drug Administration, this estimate suggests fistulizing Crohn's disease is an orphan condition. This literature-based estimate should be interpreted with caution due to the limited availability of published epidemiological studies. We note, however, that this estimate was highly consistent with a separate estimate derived from a large healthcare database.