Table 1. COHORT A characteristics comparing non-IBD controls with IBD cases (≥15 years).
| Characteristics | Non-IBD (n (%)) | Crohn’s Disease (n (%)) | Ulcerative Colitis(n (%)) | IBD (NOS) (n (%)) | P 6 |
|---|---|---|---|---|---|
| Total number | 75735 (79.8%) | 4620 (4.9%) | 12397 (13.1%) | 2146 (2.2%) | |
| Male | 36028 (47.6%) | 1991 (43.0%) | 5883 (47.5%) | 913 (42.5%) | <0.001 |
| Age | |||||
| 15-34y | 21759 (28.7%) | 1816 (39.3%) | 2960 (23.9%) | 699 (32.6%) | |
| 35-49y | 19365 (25.6%) | 1115 (24.1%) | 3182 (25.7%) | 591 (27.5%) | |
| 50-64y | 17089 (22.6%) | 886 (19.2%) | 3036 (24.5%) | 421 (19.6%) | |
| 65+y | 17522 (23.1%) | 803 (17.4%) | 3219 (26.0%) | 435 (20.3%) | |
| Mean age at entry (SD) | 48.8 (SD 18.9) | 44.2 (SD 18.9) | 50.9 (SD 18.5) | 46.9 (SD 19.0) | <0.001 |
| IBD severity 1 | |||||
| Mild | - | 2325 (50.3%) | 8141 (65.7%) | 1424 (66.4%) | |
| Moderate | - | 1572 (34.0%) | 3220 (26.0%) | 594 (27.7%) | |
| Severe | - | 723 (15.7%) | 1036 (8.4%) | 128 (6.0%) | |
| Smoker 2 | |||||
| Never | 27635 (54.4%) | 540 (60.1%) | 1429 (68.1%) | 232 (66.7%) | |
| Ever | 23120 (45.6%) | 358 (39.9%) | 669 (31.9%) | 116 (33.3%) | <0.001 |
| BMI 3 | |||||
| <10 | 4 (0.0%) | 1 (0.0%) | 1 (0.0%) | 0 (0.0%) | |
| 11–15 | 197 (0.3%) | 29 (0.8%) | 37 (0.4%) | 6 (0.3%) | |
| 16–18.49 | 1415 (2.3%) | 195 (5.2%) | 259 (2.6%) | 51 (2.9%) | |
| 18.5–24.9 | 25499 (40.8%) | 1769 (47.0%) | 4220 (41.8%) | 769 (43.2%) | |
| 25–30 | 22523 (36.0%) | 1130 (30.0%) | 3557 (35.3%) | 622 (34.9%) | |
| >30 | 12878 (20.6%) | 645 (17.1%) | 2014 (20.0%) | 333 (18.7%) | |
| Mean (SD) | 26.5 (SD 5.4) | 25.4 (SD 5.5) | 26.3(SD 5.3) | 26.2 (SD 5.68) | 0.198 |
| Practice IMD 4 | |||||
| 0 | 4758 (20.6%) | 271 (14.2%) | 811 (16.1%) | 108 (13.7%) | <0.001 |
| 1 | 4797 (20.7%) | 391 (20.5%) | 1010 (20.1%) | 160 (20.3%) | <0.001 |
| 2 | 3451 (14.9%) | 374 (19.6%) | 967 (19.2%) | 138 (17.5%) | <0.001 |
| 3 | 6320 (27.3%) | 443 (23.2%) | 1193 (23.7%) | 205 (26.1%) | <0.001 |
| 4 | 3836 (16.6%) | 431 (22.6%) | 1050 (20.9%) | 176 (22.4%) | <0.001 |
| Comorbidities | |||||
| Rheumatoid Arthritis | 1180 (1.6%) | 101 (2.2%) | 321 (2.6%) | 43 (2.0%) | <0.001 |
| Diabetes type 2 | 4869 (6.4%) | 214 (4.6%) | 849 (6.9%) | 108 (5.0%) | 0.108 |
| Diabetes type 1 | 599 (0.8%) | 42 (0.9%) | 153 (1.2%) | 22 (1.0%) | <0.001 |
| Chronic kidney disease | 3567 (4.7%) | 156 (3.4%) | 590 (4.8%) | 91 (4.2%) | 0.046 |
| Contraceptive use | 7954 (10.5%) | 1004 (21.7%) | 1757 (14.2%) | 459 (21.4%) | <0.001 |
| IBD drug use 5 | |||||
| 5-Aminosalicylic acid | 445 (0.6%) | 3264 (70.7%) | 9085 (73.3%) | 1380 (64.3%) | <0.001 |
| Oral Corticosteroids | 10178 (13.4%) | 3140 (68.0%) | 8046 (64.9%) | 1243 (57.9%) | <0.001 |
| Azathioprine/methotrexate | 650 (0.9%) | 1456 (31.5%) | 1983 (16.0%) | 326 (15.2%) | <0.001 |
| Tumour necrosis factor α antagonists | 58 (0.8%) | 14 (0.3%) | 111 (0.9%) | 16 (0.8%) | <0.001 |
| Charlson Score 5 | |||||
| 0 | 43422 (70.2%) | 2458 (62.6%) | 5930 (59.7%) | 1116 (62.1%) | |
| 1 | 10430 (16.9%) | 908 (23.1%) | 2204 (22.2%) | 414 (23.0%) | |
| 2 | 4190 (6.8%) | 277 (7.1%) | 877 (8.8%) | 132 (7.3%) | |
| 3 | 2109 (3.4%) | 146 (3.7%) | 468 (4.7%) | 70 (3.9%) | |
| 4 | 834 (1.3%) | 65 (1.7%) | 210 (2.1%) | 30 (1.7%) | |
| 5 | 438 (0.7%) | 23 (0.6%) | 89 (0.9%) | 9 (0.5%) | |
| 6 or more | 459 (0.7%) | 51 (1.3%) | 154 (1.6%) | 27 (1.5%) | <0.001 |
| Major abdominal surgery 6 | 0 (0.0%) | 635 (16.2%) | 712 (7.2%) | 102 (5.7%) | <0.001 |
| Stoma | 0 (0.0%) | 222 (5.7%) | 460 (4.6%) | 51 (2.8%) | <0.001 |
1Estimated using IBD-drug use and surgical interventions during follow-up as proxies (see text for further detail)
2 43% of patients had missing data
3 17.4% of patients had missing data
4Index of Multiple Deprivation (IMD) based on practice post-code. Quintile 0 is the least deprived, quintile 4 is the most deprived. 67.5% of patients had missing data.
5Ever in patient record
6 Non-IBD compared to IBD, comparison of binary variables by adjusted χ2 test; continuous variables by Student’s t-test; multiple category variables by χ2 test adjusted for trend.