Epidemiology of Pediatric IBD in a Population-based Cohort in Southern Alberta, Canada (1983–2005)

Aim: To examine the incidence and clinical features of Inflammatory Bowel Disease (IBD) in geographically derived cohort of children in Southern Alberta, Canada between 1983 and 2005.

Methods: All children with IBD residing in four Health Regions of Southern Alberta are referred to GI Clinic at Alberta Children's Hospital; a tertiary pediatric care center. Incidence of Crohn's Disease (CD), Ulcerative Colitis (UC) and Indeterminate Colitis (IC) in the population of children 0-17 years was determined by retrospective review of inpatient and outpatient records fulfilling previously described criteria of IBD.

Results: 179 patients have been diagnosed with IBD between 1999 and 2005 (CD - 107, UC - 53 or IC – 19). Together with 176 patients reported earlier ⁽¹⁾ diagnosed between 1983-1998 it allowed us to evaluate records of 355 patients. The mean annual incidence of IBD increased further in the period 1999-2005 comparing with previous periods as shown in Table 1.

TABLE 1: Mean annual incidence per 100, 000 children

The 2005 prevalence of pediatric IBD in Southern Alberta was 40.4 with 22, 13.7, and 4.8 per 100,000 children for CD, UC and IC respectively. The mean age of presentation of CD was 12 yr (range of 9 months to 17 yr), for UC 10 yr (range 1 to 17yr), and 10 yr for IC (range 2-17 yr). Sex distribution of patients was 55% male; CD – 61%; UC – 48% male; for IC - 37% male.

TABLE 2: CD location at diagnosis

UC location at diagnosis: pancolitis – 88%, distal colitis – 12%. Perianal disease was found in 32% in CD patients, in UC in 11%.

Conclusion: The incidence of IBD in children in Southern Alberta has been rising over last decade due to increasing incidence of CD and IC. Younger children, especially 0-5 yr present with more severe phenotype of CD. Further longitudinal prospective studies are required to asses the outcome of the early onset IBD.