Perianal Crohn's Disease Is Associated With Poor Disease Outcome: A Nationwide Study From the epiIIRN Cohort

BACKGROUND & AIMS

Limited population-based data have explored perianal involvement in Crohn's disease (CD) and compared the disease course between severe and non-severe perianal CD (PCD). We aimed to explore the disease course of these phenotypes in a population-based study of CD.

METHODS

Cases were identified from the epi-IIRN cohort and included 2 Israeli health maintenance organizations covering 78% of the population. We validated specific algorithms to identify fistulizing PCD and to differentiate severe from non-severe disease by medication utilization, International Classification of Disease, 9th Revision codes, and perianal procedures.

RESULTS

A total of 12,904 CD patients were included in an inception cohort from 2005 (2186 pediatric-onset, 17%) providing 86,119 person-years of follow-up. Fistulizing PCD was diagnosed in 1530 patients (12%) (574 with severe PCD, 4%). The prevalence of PCD was 7.9%, 9.4%, 10.3%, and 11.6% at 1, 3, 5, and 10 years from CD diagnosis, respectively. At 5 years, PCD patients were more likely to be hospitalized (36% in non-PCD vs 64% in PCD; P < .001), undergo inflammatory bowel disease-related surgeries (9% vs 38%, respectively; P < .001), and develop anorectal cancer (1.2/10,000 person-years for non-PCD vs 4.2/10,000 for PCD; P = .01). Severe PCD was associated with poorer outcomes compared with non-severe PCD, as shown for hospitalizations (61% in non-severe PCD vs 73% in severe; P = .004) and surgeries (35% vs 43%; P = .001).

CONCLUSIONS

Despite higher utilization of immunomodulators and biologics, PCD is associated with poor disease outcomes, especially in severe PCD.

Epidemiology of Inflammatory Bowel Diseases in Israel: A Nationwide Epi-Israeli IBD Research Nucleus Study

BACKGROUND

There are currently no nationwide data on the epidemiology of inflammatory bowel diseases (IBD) in Israel. We aimed to determine the population-based epidemiological trends of IBD in the diverse Israeli population.

METHODS

Health-administrative data were retrieved from all 4 Israeli health maintenance organizations, insuring 98% of the population, using validated identification algorithms. National trends were determined using Joinpoint regression analysis calculating annual percent change and average annual percent change (AAPC).

RESULTS

By 2019, there were 46,074 patients with IBD in Israel, corresponding to a national prevalence of 519/100,000 (0.52%), of whom 54.1% had Crohn disease (CD) and 45.9% had ulcerative colitis (UC). The number of Jewish patients doubled from 18,701 in 2005 (354/100,000) to 38,950 (589/100,000) in 2018 (AAPC, +4.0%; P < 0.05), and the number of Arab patients increased 3-fold from 1096 (102.1/100,000) to 3534 (240.7/100,000; AAPC, +6.8%; P < 0.05) during the same years. However, the increase rate has gradually decelerated over time (annual percent change during 2005-2008, 2009-2014, and 2005-2018 was +6.7%, +4.2%, and +2.3%, respectively; P < 0.05). Pediatric prevalence increased from 37.4 to 52.2/100,000, with CD predominating in both Jews and Arabs. The incidence of CD remained stable (from 15.9/100,000 to 14.9/100,000) and the incidence of UC decreased (15.4/100,000 to 10.5/100,000 (AAPC, -3.2%; P < 0.001)). In contrast, pediatric incidence of CD increased from 7.3/100,000 to 8.3/100,000 (AAPC, +1.9%; P < 0.05) and that of UC increased from 2.6 to 4.4/100,000 (AAPC, +5.8%; P < 0.05).

CONCLUSIONS

The IBD prevalence rate in Israel is still increasing but gradually decelerating, probably due to the decreasing overall IBD incidence. Nonetheless, incidence rate in children is still increasing. Ongoing narrowing in the rates between Jews and Arabs over time may indicate shared environmental factors.