Table 1.

General characteristics of included studies

StudyStudy designCase (N)Control (N)Male (N)Female (N)Age rangeColon cancer (N)Rectal cancer (N)Total (N)
CCFRCase–control1,1639771,0721,06820–814452862,140
Colo2&3Case–control871251179538–865927212
DACHSCase–control2,3762,2062,7521,83033–991,4229494,582
DALSCase–control1,1161,1741,2611,02928–791,11202,290
HPFSNested case–control173230403048–8111341403
MECNested case–control32834636131345–7624181674
NHSNested case–control37595501,33044–69285861,330
PHSNested case–control375389764040–8528684764
PLCONested case–control48641551838355–75320161901
PMH-CCFRCase–control280122040248–7320664402
OFCCRCase–control65052256261029–774331971,172
VITALNested case–control28528830027350–7621566573
WHINested case–control1,4661,53102,99750–791,1492612,997
Total9,1609,2808,11010,33020–996,2862,30318,440