Tu1301 Adult and Pediatric IBD Incidence in the UK: A Large Population-Based Study Using the General Practice Research Database

Abstract

Background: studies of the incidence of Inflammatory Bowel Disease suggest that Crohn's disease (CD) incidence may be rising, while that of ulcerative colitis (UC) has remained stable in recent years. Incidence of pediatric CD particularly appears to be rising. Studies of IBD incidence in the UK have been limited to smaller and geographically narrow populations. The current study aims to define the incidence of both adult and pediatric IBD (CD and UC) using the UK General Practice Research Database (GPRD). Methods: The GPRD contains over 11 million contributing patients. Incident cases of CD and UC were identified from 1990-2010 in ‘up-to-standard' GP practices within the GPRD. Cases were considered incident if the first-mention of IBD occurred at least 12 months after both registration with the GP and the first date of up-to-standard data for the physician's practice. Annual incidence rates were determined for adults and pediatric groups separately, using the total mid-year population in the GPRD for the given year. Poisson regression was used to model fully adjusted (by sex and age) incidence rate ratios. Results: 17181 incident cases of IBD (6446 CD, 10657 UC, 78 IBD-undiagnosed) were identified in the GPRD from 1990-2010. The 10-year average annual incidence rate of CD and UC was higher from 2000-09, compared with 1990-99 (Table). However, rates for both UC and CD have remained stable from 200009 (p=0.72 & 0.16, respectively). Incidence was significantly higher for females in the CD cohort (12.5 vs 9.9/105pt.yr), but higher in males in the UC cohort (20.2 vs 18.3/105pt.yr). In CD, incidence was highest in the 16-25 year age group (15.8/105pt.yr), while UC incidence gradually increased with age, and was highest in the 66-75 year age group (27.2/105pt.yr). In the pediatric population, CD incidence has continued to rise throughout the past decade (4/105pt.yr for the period 2007-09), particularly for males (4.3 vs 2.6/105pt.yr). Pediatric UC incidence increased from 2000-2006 (peak 3.6/105pt.yr), but has since leveled off (2.8/ 105pt.yr in 2009). Conclusions: Adult CD and UC incidence is higher than previously reported in the UK, but has been stable over the past decade, and corresponds to previously reported age and sex distribution. Pediatric CD and UC incidence have continued to rise over the past 10 years, but in UC appears to have more recently stabilized. Particular attention should be drawn to the increased incidence of CD in the pediatric male population. Table: 10-year average annual incidence of IBD Adult patients only (≥ 16 yrs)