Table 1.

Characteristics of included studies on colectomy risk in Ulcerative Colitis

Study	Country	Data Source	Study Span (Year)	Sample Size	Age Group	Sex (%)	Extent of Disease (%)	Time Intervals Reported (Years)
Benchimol et al,16 2010	Canada	Ontario Province	1994 – 2004	-	Pediatric	-	-	3
Charpentier et al,17 2014	France	EPIMAD	1988 – 2006	474	Elderly	M (62), F (38)	E1 (29), E2 (45), E3 (26)	1, 5, and 10
Chhaya et al,18 2015	UK	CPRD	1989 – 2009	8673	All ages	M (52), F (48)	-	1, 5, and 10
Chow et al,19 2009	China	Prince of Wales Hospital	1985 – 2006	172	All ages	M (52), F (48)	E1 (28), E2 (30), E3 (42)	1 and 10
Eriksson et al,20 2017	Sweden	Orebro University Hospital	1963 – 2005	835	All ages	-	-	10
Gheorge et al,21 2004	Romania	18 secondary and tertiary centers	2002 – 2003	163	Adults	M (56), F (44)	E1 (22), E2 (54), E3 (24)	1
Gower-Rousseau et al,22 2014	France	EPIMAD	1988 – 2004	159	Pediatric	M (42.1), F (57.9)	E1 (25), E2 (38), E3 (37)	1, 5, and 10
Guasch et al,23 2018	Spain	ENEIDA	1995 – 2000, 2007 – 2012	8028	All ages	-	-	1 and 5
Lakatos et al,24 2011	Hungary	Veszprem Province	2002 – 2006	220	All ages	M (56.8), F (43.2)	E1 (27), E2 (51), E3 (22)	1 and 5
Langholz et al,25 1997	Denmark	Copenhagen	1962 – 1987	80	Pediatric	M (53), F (47)	E1 (25), E2 (43), E3 (29)	1, 5 and 10
Leijonmarck et al,26 1990	Sweden	Stockholm County	1955 – 1984	1586	All Ages	-	-	1, 5 and 10
Lirhus et al,27 2018	Norway	Norwegian Patient Registry	2010 – 2012	5428	All Ages	M (52.8), F (47.2)	-	3
Lund et al,28 2019	Denmark	DNPR	1977 – 2016	4449	Pediatric	-	-	5
Malaty et al,29 2013	USA	Single Pediatric Center	1989 – 2003	112	Pediatric	M (45), F (55)	E1 (25), E2 (40), E3 (35)	1 and 5
Nguyen et al,30 2017	Canada	Ontario Province	1999 – 2008	12233	Adult	M (48.7), F (51.3)	-	5 and 10
Niewiadomski et al,31 2015	Australia	Barwon Area	2007 – 2008, 2010 – 2013	96	All ages	-	-	1 and 5
Nordenvall et al,32 2018	Sweden	Swedish Patient Register	2002 – 2014	2295	Pediatric	M (54), F (46)	-	3
O’Keefe et al,33 1989a	South Africa	Cape Town	1970 – 1979	91 (5y), 61 (10y)	All ages	-	-	5 and 10
Parragi et al,34 2018	Switzerland	SIBDCS	2006 – 2015	1245	All ages	M (54.6), F (45.4)	E1 (20), E2 (32), E3 (38)	5 and 10
Probert et al,35 1993	England	Leicestershire	1972 – 1989	691	All ages	-	-	5 and 10
Ronnblom et al,36 2016	Sweden	Uppsala Healthcare Region	2005 – 2009	524	All ages	M (55.2), F (44.8)	E1 (32), E2 (31), E3 (31)	1 and 5
Rungoe et al,11 2014	Denmark	DNPR	1979 – 2011	35782	All ages	M (47), F (53)	-	1, 5, and 9
Samuel et al,37 2013	USA	Olmsted County	1970 – 2004	369	All ages	M (58), F (42)	E1 (29), E2 (37), E3 (32)	1, 5, and 10
Solberg et al,38 2009	Norway	IBSEN	1990 – 1993	519	All ages	M (51.4), F (48.6)	E1 (33), E2 (35), E3 (32)	1, 5, and 10
Spizzo et al,39 2016	Australia	GECCO	2007 – 2015	41	All ages	-	-	4
Targowinik et al,40 2012	Canada	UMIBDED	1984 – 2008	3752	All Ages	M (48), F (52)	-	1, 5, and 10

M: Male, F: Female, E1: Proctitis, E2: Left-sided Colitis, E3: Pancolitis