Table 2.
Baseline characteristics of all patients with childhood onset (<18 years) inflammatory bowel disease in Sweden 1964-2014 and reference individuals from the general population matched for sex, age, birth year, and place of residence. Numbers are n (%) unless otherwise stated.
| Characteristic | Inflammatory bowel disease | Ulcerative colitis | Crohn’s disease | IBD unclassified | Reference individuals |
|---|---|---|---|---|---|
| Total | 9405 | 4648 (49.4) | 3768 (41.1) | 989 (10.5) | 92 870 |
| Female | 4201 (44.7) | 2121 (45.6) | 1628 (43.2) | 452 (45.7) | 41 478 (44.7) |
| Male | 5204 (55.3) | 2527 (54.4) | 2140 (56.8) | 537 (54.3) | 51 392 (55.3) |
| Age of first diagnosis or cohort entry (years)* | |||||
| Mean (SD) | 14 (4) | 14 (4) | 14 (3) | 14 (4) | 14 (4) |
| Median (IQR) | 15 (12-16) | 14 (12-16) | 15 (12-17) | 15 (12-16) | 15 (12-16) |
| <6 | 395 (4.2) | 232 (5.0) | 108 (2.9) | 55 (5.6) | 3919 (4.2) |
| <10 | 1332 (14.2) | 747 (16.1) | 434 (11.5) | 151 (15.3) | 13 187 (14.2) |
| <15 | 5174 (55.0) | 2591 (55.7) | 2050 (54.4) | 533 (53.9) | 51 160 (55.1) |
| <17 | 7821 (83.2) | 3884 (83.6) | 3116 (82.7) | 821 (83.0) | 77 261 (83.2) |
| <18 | 9405 (100) | 4648 (100) | 3768 (100) | 989 (100) | 92 870 (100) |
| Year of first diagnosis or cohort entry | |||||
| 2002-14 | 4642 (49.4) | 2077 (44.7) | 1992 (52.9) | 573 (57.9) | 45 773 (49.3) |
| 1990-2001 | 2363 (25.1) | 1285 (27.6) | 848 (22.5) | 230 (23.3) | 23 398 (25.2) |
| 1980-89 | 1375 (14.6) | 724 (15.6) | 542 (14.4) | 109 (11.0) | 13 576 (14.6) |
| 1964-1979 | 1025 (10.9) | 562 (12.1) | 386 (10.2) | 77 (7.8) | 10 123 (10.9) |
*Fig 1 shows the distribution of age at first diagnosis.