Incidence, Prevalence, and Time Trends of Pediatric Inflammatory Bowel Disease in Northern California, 1996 to 2006

Objective To examine the incidence and prevalence of pediatric inflammatory bowel disease (IBD) during 1996 2006 in a community-based health-care delivery system. Study design Members of Kaiser Permanente Northern California aged 0 to 17 years with IBD were identified by use of computerized medical information with confirmation obtained through review of the medical record. Results The average annual incidence of IBD per 100 000 was 2.7 (95% confidence interval [CI], 2.3-3.1) for Crohn's disease (CD) and 3.2 (CI, 2.8-3.6) for ulcerative colitis (UC). During the 11-year study period, the annual incidence per 100 000 increased from 2.2 to 4.3 for CD (P = .09) and from 1.8 to 4.9 for UC (P < .001). The ratio of incident CD cases to incident UC cases was 0.9 in non-Hispanic whites, 1.6 in African Americans (P = .12), 0.3 in Hispanics (P < .001) and 0.4 in Asians (P = .04). The average length of enrollment during the 11-year study period exceeded 8 years. The point prevalence on December 31, 2006, per 100 000 was 12.0 for CD (CI, 9.6-14.4) and 19.5 (CI, 16.5-22.6) for UC. Conclusions In this population the incidence of UC increased significantly by 2.7-fold and CD increased 2.0-fold without reaching statistical significance. Hispanic and Asian children had development of UC more often than CD, suggesting possible etiologic differences across racial and ethnic groups. (J Pediatr 2010; 157: 233-9).