Two articles describe both increasing and decreasing trends in the prevalence of inflammatory bowel disease (IBD).

• Y Ye et al. Inflamm Bowel Dis 2020; 26: 619-25, editorial 626-27
• M Torabi et al. Inflamm Bowel Dis 2020; 26: 581-90, editorial 591-92 

The first study by Ye et al provides the familiar message that IBD prevalence has been increasing in pediatrics and adults.  This study examined 2 large claims databases.  The Optum database covered ~18 million annually during the study period (total ~57 million from 2007-2017) and Truven covered ~44 million annually (total ~240 million since 1995)

Key findings:

• Pediatric IBD prevalence increased by 133% from 2007 to 2016: from 33 per 100,000 to 77 per 100,000. Crohn’s disease (CD) was twice as prevalent as ulcerative colitis (UC) in the pediatric population (46 vs 22)
• Adult IBD prevalence increased by 123% from 2007 to 2016: from 215 per 100,000 to 478 per 100,000. The prevalence rates of CD and UC were similar in adults: 198 vs 181)
• The Northeast region had the highest prevalence of IBD, followed by Midwest, South and then West.
• Based on these prevalence data, there are an estimated 58,000 children (2-17) and 1.2 million adults with IBD in U.S.   Or, 1 in 1299 children and 1 in 209 adults.

Limitations:

• Diagnosis and data derived from claims database
• Cases can vary significantly based on how sensitive the definition for IBD is in a given study.  In this study, the authors indicate in supplementary material, that the prevalence rates could be doubled in adults if they chose a more sensitive/less specific case definitions.

The second study by Torabi et al, which utilized the Manitoba Epidemiology Database (n=1.2 million) showed a decrease in IBD incidence.  The authors examined 296 small geographic areas (SGAs) and found that many had persistently high IBD incidence rates.

Key findings:

• The incidence of IBD decreased from 1990 when it was 23.6 per 100,000 to 16.2 per 100,000 in 2012.
• In the study period (1990-2012), there were 3114 cases of CD and 3499 cases of UC diagnosed in Manitoba

In the discussion, the authors speculate on the reasons for the decline in IBD incidence in an area with high rates of IBD.  Some of the change may be related to changes in the population mix –more immigrants from areas with lower rates of IBD.  In the editorial, it is noted that a recent systematic review (Lancet 2018; 390: 2769-78) indicated that the “incidence of IBD is stabilizing in Western countries.”

My take: There are a lot kids and adults with IBD.  The preponderance of epidemiology studies point to increasing incidence and prevalence.

Related blog posts:

• Connecting Diet and Epidemiology in Inflammatory Bowel Disease  –includes image of increasing incidence/prevalence over >150 years
• Patterns and Puzzles with Very Early Onset Inflammatory Bowel Disease | gutsandgrowth
• More IBD Cases Than Ever in Young Canadian Children | gutsandgrowth

Rock art during “social distancing”