Systematic Reviews
Copyright ©The Author(s) 2018.
World J Gastroenterol. Jan 21, 2018; 24(3): 424-437
Published online Jan 21, 2018. doi: 10.3748/wjg.v24.i3.424
Table 1 Incidence of Crohn’s disease and ulcerative colitis
Study characteristics and demographicsStudy quality characteristics
StudyCountry (region)Study periodNumber of casesIncidence rate/100000Diagnosis based on recognised criteriaEthnicity reporting methodSample frame

SACaucasian

Crohn's disease
Fellows (1985)[11]United Kingdom (Derby)1966-19852214.47.5NoSelf-reportedHospital
Probert (1992)[6]United Kingdom (East London)1970-79451.23.8YesMedical recordsHospital
1980-89542.33.8
Jayanthi (1992)[17]United Kingdom (Leicester)1972-1980801.23.5YesSurnamePopulation
1981-19891043.15.3
Pinsk (2007)[12]Canada (Vancouver)1985-2005397 (Paed)6.71.0YesMedical recordsHospital
Benchimol1 (2015)[13]Canada (Ontario)1994-2010121135.011.3NoMedical recordsPopulation
Ulcerative colitis
Probert (1992)[5]United Kingdom (Leicester)1972-1989100310.85.3NoSurnamePopulation
Jayanthi (1992)[14]United Kingdom (East London)1972-19891121.86.2NoMedical recordsHospital
Carr (1999)[15]United Kingdom (Leicester)1991-19947417.29.1YesSelf-reportedPopulation
Pinsk (2007)[12]Canada (Vancouver)1985-2005120 (Paed)6.43.7NoMedical recordsHospital
Probert (1985)[16]Fiji1985-1986151.50.2NoMedical recordsHospital
Benchimol1(2015)[13]Canada (Ontario)1994-2010127132.011.4NoMedical recordsPopulation
Table 2 Prevalence of Crohn’s disease: Study characteristics and comparison between Caucasian and other migrant groups
Study characteristicsStudy quality characteristics
StudyCountry (region)Study periodNumber of casesPrevalence rate, cases/100000Diagnosis based on recognised criteriaEthnicity reporting methodSample frame

SAAsianCaucasianBlackHispanic

Probert (1993)[18]United Kingdom (Leicester)198967633.2-75.8--YesSelf-reportedPopulation
Kurata (1992)[19]United States (California)1982-1988169-5.643.629.84.1NoMedical recordsHospital
Wang (2013)[20]United States (National Database)1996-2007204-45.0154.068.015.0NoSelf-reportedPopulation
Table 3 Prevalence of ulcerative colitis: Study characteristics and comparison between population groups
Study characteristicsStudy quality characteristics
StudyCountry (region)Study periodNumber of casesPrevalence rate, cases/100000Diagnosis based on recognised criteriaEthnicity reporting methodSample frame

SAAsianCaucasianBlackHispanic

Probert (1993)[18]United Kingdom (Leicester)1989888136.0-90.8--YesSelf-reportedPopulation
Wang (2013)[20]United States (National database)1996-2007108-40.089.02535NoSelf-reportedPopulation
SAMalayChineseBlackHispanic
Lee (2000)[21]Singapore (Singapore)1985-19965816.27.06.0--YesSelf-reportedHospital
Table 4 Meta-analysis of incidence studies showing rate ratio of South Asians relative to Caucasians
DiseaseNumber of studiesHeterogeneity
Effect size
I2P valueRR (95%CI)P value
Crohn’s disease695%< 0.0010.78 (0.22, 2.78)0.7
Ulcerative colitis483%0.0011.39 (0.84, 2.32)0.2
Table 5 Crohn’s disease location and behaviour
StudyCountry (Region)Time periodNumber of casesMontreal classificationPopulation groups, %
SACaucasian
Location
Walker (2011)[35]United Kingdom (NW London)2008-2010309L116.024.7
L246.834.8
L337.240.5
L40.00.0
Goodhand (2012)[36]United Kingdom (East London)2010141L133.032.0
L224.043.0
L338.022.0
L418.013.0
Li (2013)[22]United States (San Francisco)1994-200957 (Paed)L17.714.9
L238.523.4
L353.961.7
L415.45.3
Carroll (2016)[38]Canada (British Columbia)1997-2012638 (Paed)L16.09.0
L255.035.0
L339.055.0
L4a55.043.0
L4b1.09.0
L4ab0.08.0
Behaviour
Walker (2011)[35]United Kingdom (NW London)2008-2010309B172.358.1
B222.060.0
B34.314.0
Perianal20.221.4
Goodhand (2012)[36]United Kingdom (East London)2010141B163.055.0
B215.011.0
B320.015.0
Perianal16.03.0
Li (2013)[22]United States (San Francisco)1994-200957 (Paed)Perianal46.212.8
Carroll (2016)[38]Canada (British Columbia)1997-2012638 (Paed)B161.073.0
B213.016.0
B36.03.0
B2B321.09.0
Table 6 Crohn’s disease location
StudyCountry (Region)Time periodNumber of casesDisease location/ Behaviour, MontrealPopulation groups, %
AACaucasian (or other control)Hispanic
Cross (2006)[23]United States (Baltimore)1997-2005210L113.038.0-
L229.023.0-
L356.036.0-
Sofia (2014)[40]United States (Chicago)2008-20131334L157.871.0-
L260.666.0-
Nguyen (2006)[24]United States (National)2003-2005697L116.129.223.3
L233.917.416.3
L322.636.752.3
L427.416.78.1
Eidelwein (2007)[25]United States (Baltimore)1991-2000137 (Paed)L13.02.9-
L273.571.8-
L323.525.2-
Hatter (2012)[26]United States (Texas)2004-2009246 (Paed)L14.34.74.8
L27.14.810.5
L387.888.984.2
Ghazi (2013)[27]United States (Baltimore)2004-2009296L131.038.0-
L212.020.0-
L355.042.0-
Damas (2013)[28]United States (Florida)1998- 2009325L1-16 (NHW)24.4
L2-24.025.6
L3-60.050.0
L4-12.53.9
Kugathasan (2003)[29]United States (National)2000-2001222 (Paed)L110.019.0-
L234.028.0-
L346.051.0-
L432.042.0-
Table 7 Crohn’s disease behaviour
StudyCountry (Region)Time periodNumber of casesDisease location/ Behaviour, MontrealPopulation groups, %
AACaucasianHispanic
Nguyen (2006)[24]United States (National)2003-2005697B153.248.045.3
B227.921.423.6
B319.030.631.1
Perianal40.028.752.5
Eidelwein (2007)[25]United States (Baltimore)1991-2000137 (Paed)B2 + B329.111.11-
Ghazi (2013)[27]United States (Baltimore)2004-2009296B118.033.0-
B242.036.0-
B340.031.0-
Perianal36.025.0-
Sofia (2014)[40]United States (Chicago)2008-20131334Perianal25.724.7-
Damas (2013)[28]United States (Florida)1998- 2009325B1-81.5 (NHW)78.9
B2-0.01.1
B3-18.520.0
Perianal-27.023.0
Kugathasan (2005)[29]United States (National)-222 (Paed)Inflammatory58.064.0-
Stricturing20.018.0-
Fistulising22.018.0-
Perianal23.036.0-
Malaty (2010)[30]Houston (Texas)2000-2006273Inflammatory64.063.058.0
Stricturing16.017.013.0
Fistulising17.016.032.0
Adler (2016)[31]Multicentre (United States and United Kingdom)2006-20142034 (Paed)Perianal26.020.024.0
Table 8 Ulcerative colitis in Caucasian and South Asian migrant groups (1054 cases)
StudyCountry (Region)Study periodNumber of casesDisease extent, MontrealEthnic groups, %
SACaucasian (or other control)
Adult
Carr (1999)[15]United Kingdom (Leicester)1991-199474E1 + E263.768.3
E336.331.7
Rashid (2008)[37]United Kingdom (Manchester)200882E341.026.0
Walker (2011)[35]United Kingdom (NW London)2008-2010461E19.926.1
E227.131.4
E363.042.0
Goodhand (2012)[36]United Kingdom (East London)201089E12.031.0
E360.033.0
Hilmi (2009)[39]Malaysia (Malaysia)2004-2005118E1 + 239.656.7 (Malay)
E360.443.4 (Malay)
Paediatric
Carroll (2016)[38]Canada (British Columbia)1997-2012230E13.05.0
E29.019.0
E312.018.0
E477.058 (Non-South Asian)
Table 9 Ulcerative colitis in AA and Hispanic groups (1787 cases)
StudyCountry (Region)Time periodNumber of casesDisease extentEthnic groups, %
AACaucasianHispanic
Adult studies
Basu (2005)[32]United States (Texas)1999-200361E1-32.08.0
E2 + 3-68.086.0
Nguyen (2006)[24]United States (National database)2003-2005396E113.85.93.6
E216.431.434.5
E351.762.780.0
Eidelwein (2007)[25]United States (Baltimore)1991-200040E1 + 20.010.0-
E3100.023.0-
Moore (2012)[33]United States (Ohio)2000-2010311E114.56.5-
E244.730.7-
E340.862.9-
Sofia (2014)[40]United States (Chicago)2008-2013541E117.911.1-
E228.632.0-
E350.051.5-
Damas (2013)[28]United States (Florida)1999-2009138E1-11.812.5
E2-29.446.2
E3-58.841.3
Paediatric
Flasar (2008)[34]United States (Baltimore)1997-2005197E123.010.0-
E223.031.0-
E353.059.0-
Hatter (2012)[26]United States (Texas)2004-2009103E1 + 27.115.418.8
E381.384.681.3