Patient Demographics
For reasons unknown, Crohn's disease (CD) is largely a disease of the developed world, with most cases of CD appearing in Europe and the United States. As many as 1.4 million persons in the United States and 2.2 million persons in Europe suffer from inflammatory bowel disease (IBD).1 The total number of cases of CD and ulcerative colitis (UC) are approximately equal. Substantial increases in both UC and CD incidence and prevalence have been noted in North America and Western Europe since the Second World War.2 Additionally, CD and UC seem to be more prevalent in urban than rural areas.3
Below is a chart showing the prevalence of IBD in some developed areas of the world.
The estimated incidence of CD in North America is between 3.1 and 14.6 new cases per 100,000 person-years.1 Prevalence ranges from 26 to 199 cases per 100,000 people.1 With extrapolation of this data to the entire populations of the United States and Canada in 2003, between 10,000 and 47,000 people are diagnosed with CD in North America each year.1
An interesting observation is that in regions where incidence of IBD is increasing, the rising incidence of UC has seemed to precede that of CD by approximately 10 to 20 years. This observation has been made worldwide, in countries such as Sweden, Iceland, Denmark, the Faroe Islands, and the United States.2 Another trend is increasing presentation of colonic involvement in CD. Crohn's colitis first appeared in the 1960s. The regional ileitis first described by Dr. Crohn was described in 1932, and since that time, more and more patients have presented with CD that affects areas further down the GI tract.2
Crohn's disease (as well as UC) is commonly diagnosed in late adolescence and early adulthood, mainly between the ages of 15 and 35.3 Crohn's disease is diagnosed most frequently in patients in their 20s,1 and another peak in incidence may occur in patients over the age of 60.2 Approximately 10% of patients with CD in the United States are under the age of 18.3
The chronic nature of CD and its prevalence among working-age individuals contributes to the burden that this disease places on society. The distribution of CD by sex is dependent upon the overall incidence in a certain region. More women are affected by CD in high incidence areas, and more men are affected by CD in low incidence areas. The opposite is true of UC.2
The graph below documents the average treatment progression of CD patients.4
Most patients with high and chronic disease activity will develop a stricturing or penetrating (fistulizing) complication. This can impact hospitalization and surgical costs.5
The Kaplan-Meier chart below is from a retrospective study assessing the long-term disease progression of CD in more than 2000 patients. The graph illustrates the probability of patients remaining free of penetrating (upper curve), stricturing (middle), and inflammatory (lower curve) complications.5
References:
- Loftus EV, Sandborn WJ. Epidemiology of inflammatory bowel disease. Gastroenterol Clin N Am. 2002;31:1-20.
- Ekbom A. The changing faces of Crohn's disease and ulcerative colitis. In: Targan SR, Shanahan F, Karp LC, eds. Inflammatory Bowel Disease: From Bench to Bedside. 2nd ed. New York, NY: Springer;2005:5-20.
- About Crohn's disease. Crohn's and Colitis Foundation of America. Available at: http://www.ccfa.org/info/about/crohns. Accessed November 30, 2008.
- Silverstein MD, Loftus EV, Sandborn WJ, et al. Clinical course and costs of care for Crohn's disease: Markov model analysis of a population-based cohort. Gastroenterology. 1999;117:49-57.
- Cosnes J, Cattan S, Blain A, et al. Long-term evolution of disease behavior of Crohn's disease. Inflamm Bowel Dis. 2002;8:244-250.
