Table 1

 Characteristics of gastrointestinal cancer cases and controls*. Values are numbers (percentages) unless stated otherwise

CharacteristicsOesophageal cancerGastric cancerColorectal cancer
Cases (n=2954)Controls (n=14 721)Cases (n=2018)Controls (n=10 007)Cases (n=10 641)Controls (n=53 022)
Mean years of observation7.77.77.57.57.57.5
Female sex1074 (36)5345 (36)770 (38)3822 (38)4900 (46)24 450 (46)
Age (years) at index date:
 40-59489 (17)2446 (17)194 (10)965 (10)1764 (17)8820 (17)
 60-791706 (58)8523 (58)1163 (58)5818 (58)6162 (58)30 807 (58)
 ≥80759 (25)3752 (25)661 (33)3224 (32)2715 (26)13 395 (25)
Smoking status:
 Never1208 (41)7164 (49)897 (44)4937 (49)5356 (50)26 825 (51)
 Past680 (23)2970 (20)494 (25)1958 (20)2409 (23)10 464 (20)
 Current729 (25)2405 (16)396 (20)1544 (15)1665 (16)8123 (15)
 Missing337 (11)2182 (15)231 (11)1568 (16)1211 (11)7610 (14)
Alcohol intake:
 Non-drinker466 (16)2256 (15)389 (19)1664 (17)1649 (15)8277 (16)
 Drinker1893 (64)8909 (61)1206 (60)5777 (58)6777 (64)31 958 (60)
 Missing595 (20)3556 (24)423 (21)2556 (26)2215 (21)12 757 (24)
Body mass index (kg/m2):
 <25.0811 (27)3883 (26)548 (27)2631 (26)2840 (27)14 573 (27)
 25.0-29.9864 (29)4459 (30)567 (28)2873 (29)3203 (30)15 694 (30)
 ≥30.0403 (14)1906 (13)258 (13)1203 (12)1472 (14)6808 (13)
 Missing876 (30)4473 (30)645 (32)3300 (33)3126 (29)15 947 (30)
Prescribed oral bisphosphonate90 (3.0)345 (2.3)49 (2.4)270 (2.7)276 (2.6)1555 (2.9)

*Five controls matched to each case by age at diagnosis of case (index date) to within 2 years, sex, general practice, and observation period in General Practice Research Database.