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.