Table 1

Covariate summary statistics for ulcerative colitis, Crohn’s disease and control cohorts

With CD (n=7469)Matched cohort without CD (n=29 876)With UC (n=11 360)Matched cohort without UC (n=45 440)
Age at study entry (years) Median (IQR)47 (34, 61)48 (33, 63)53 (39, 67)52 (37, 67)
Male sex3402 (45.5)14 085 (47.1)5737 (50.5)22 433 (49.4)
Time since GP practice registration (years) median (IQR)10 (2, 20)11 (3, 20)11 (3, 21)11 (3, 21)
Duration of IBD (years) median (IQR)9 (2, 17)NA9 (2, 18)NA
Ethnicity
 Asian247 (4.2)1402 (6.0)547 (6.1)2239 (6.3)
 Black72 (1.2)599 (2.6)93 (1.0)811 (2.3)
 Mixed55 (0.9)246 (1.1)63 (0.7)361 (1.0)
 Other41 (0.7)235 (1.0)68 (0.8)299 (0.8)
 White5399 (92.9)20 732 (89.3)8270 (91.5)32 058 (89.6)
BMI category (kg/m2)
 Underweight (≤18.5)369 (4.9)800 (2.7)256 (2.3)1094 (2.4)
 Normal weight (18.5–25)3020 (40.4)10 170 (34.0)4230 (37.2)14 905 (32.8)
 Overweight (25-30)2125 (28.5)8819 (29.5)3684 (32.4)14 399 (31.7)
 Obese (≥30)1304 (17.5)6307 (21.1)2223 (19.6)9744 (21.4)
 BMI not recorded651 (8.7)3780 (12.7)967 (8.5)5298 (11.7)
Smoking status
 Non-smoker2641 (35.4)12 511 (41.9)4255 (37.5)18 288 (40.2)
 Current smoker1731 (23.2)6135 (20.5)1386 (12.2)8881 (19.5)
 Ex-smoker3028 (40.5)10 632 (35.6)5631 (49.6)17 594 (38.7)
 Smoking status not recorded69 (0.9)598 (2.0)88 (0.8)677 (1.5)
Index of multiple deprivation quintile
 1 (most deprived)1015 (13.6)4130 (13.8)1293 (11.4)5534 (12.2)
 21185 (15.9)4738 (15.9)1626 (14.3)6694 (14.7)
 31484 (19.9)5867 (19.6)2143 (18.9)8779 (19.3)
 41765 (23.6)6840 (22.9)2862 (25.2)11 024 (24.3)
 5 (least deprived)1860 (24.9)7704 (25.8)3230 (28.4)12 579 (27.7)
 IMD not recorded160 (2.1)597 (2.0)206 (1.8)830 (1.8)
Alcohol intake
 Non-drinker1158 (15.5)3945 (13.2)1495 (13.2)5799 (12.8)
 Within limits4178 (55.9)16 449 (55.1)6724 (59.2)25 880 (57.0)
 Over recommended limits991 (13.3)4390 (14.7)1691 (14.9)6882 (15.1)
 Alcoholism119 (1.6)505 (1.7)172 (1.5)774 (1.7)
 Alcohol intake not recorded1023 (13.7)4587 (15.4)1278 (11.2)6105 (13.4)
Comorbidities
 Hypertension1292 (17.3)5894 (19.7)2704 (23.8)10 929 (24.1)
 Hyperlipidaemia1391 (18.6)7462 (25.0)3293 (29.0)13 480 (29.7)
 Type two diabetes436 (5.8)1992 (6.7)1052 (9.3)3674 (8.1)
 Peripheral vascular disease81 (1.1)276 (0.9)139 (1.2)584 (1.3)
 Atrial fibrillation172 (2.3)797 (2.7)388 (3.4)1479 (3.3)
 Myocardial infarction172 (2.3)694 (2.3)424 (3.7)1360 (3.0)
 Angina139 (1.9)531 (1.8)337 (3.0)1101 (2.4)
 Stroke119 (1.6)430 (1.4)226 (2.0)831 (1.8)
 Heart failure87 (1.2)322 (1.1)179 (1.6)675 (1.5)
 CKD stages 3–5406 (5.4)1344 (4.5)796 (7.0)2897 (6.4)
 COPD111 (1.5)179 (0.6)235 (2.1)285 (0.6)
 Chronic liver disease364 (4.9)922 (3.1)489 (4.3)1696 (3.7)
 Malignancy315 (4.2)1308 (4.4)689 (6.1)2479 (5.5)
 Dementia136 (1.8)611 (2.0)292 (2.6)1230 (2.7)
 Rheumatoid arthritis85 (1.1)194 (0.6)157 (1.4)383 (0.8)
 History of fracture612 (8.2)2371 (7.9)1017 (9.0)3721 (8.2)
 Depression1160 (15.5)3091 (10.3)1461 (12.9)4786 (10.5)
Baseline medication use
 Rectal 5-ASA329 (4.4)25 (0.1)2415 (21.3)35 (0.1)
 Rectal glucocorticoids340 (4.6)263 (0.9)1793 (15.8)395 (0.9)
 Oral 5-ASA2868 (38.4)97 (0.3)6986 (61.5)212 (0.5)
 Oral glucocorticoids2290 (30.7)1780 (6.0)2937 (25.9)3103 (6.8)
 Non-biologic immunosuppressants2274 (30.4)207 (0.7)1600 (14.1)377 (0.8)
 Biologic therapies182 (2.4)6 (0.0)59 (0.5)7 (0.0)
  • Data are N (%) unless stated.

  • 5-ASA, aminosalicylic acid medications; BMI, body mass index; CD, Crohn’s disease; CKD, chronic kidney disease; COPD, chronic obstructive pulmonary disease; GP, general practitioner; IBD, inflammatory bowel disease; UC, ulcerative colitis.