Inflammatory bowel disease course in Crohn’s disease: Is the natural history changing?

Table 1 Surgery trends for Crohn’s disease in population based cohorts by years from initial diagnosis

Geographic region and time period of investigation	Time from diagnosis
	1 yr	5 yr	10 yr
North America/Asia
Olmsted County, MN, United States[38]
1970-2009		38%	48%
Manitoba, Canada[2]
1988-2008	13%	24%	32%
2001-2008	10%	18%
1South Korea[39]
1991-2007	15%	25%	33%
Europe
Sweden[21]
1955-1974		30%	50%
Denmark[25-37]
1960-1978	35%		61%
2003-2005	12%
Denmark[51]
1979-1986		44.70%
2003-2011		19.60%
Norway[28]
1990-1994	14%	27%	38%
Wales, United Kingdom[32]
1986-1991	32%	59%
1992-1997	25%	37%
1998-2003	19%	25%
Veszprem Province, Hungary[32,33]
1977-2008	15%	31%	52%
2002-2006	10%	21%
EC-IBD[29]
1991-2003			40%

¹Referral cohort.

Table 2 Key issues on the natural history of Crohn’s disease

-The distribution of location in Crohn’s disease (CD) has not changed significantly in the recent decade, but differs according to age at onset

-Recent data indicate that there are an increasing proportion of Crohn’s disease patients are diagnosed with an inflammatory disease behavior. The progression to complicated disease phenotype is decreased

-There is evidence from population-based studies that the surgery rates have recently declined in Crohn’s disease

-Data suggest that the decline in the surgical rates is partly associated with early use of thiopurines. However, the relative importance of changes in treatment strategy and patient monitoring on the natural history remain conflictive

-Overall mortality rates in CD have been higher than that in the background population, and there is only little evidence that these have changed in the last decade. In addition, an increased mortality from gastrointestinal causes is constantly reported

-Further data are needed to assess whether tight, and objective patient monitoring (including clinical, laboratory, endoscopy and imaging) or early administration of biological would lead to superior outcomes

-Cost-effectivity of the new treatment and monitoring strategies has to be established