Table 1.
Baseline characteristics of patients with adult-onset [≥18 years of age] inflammatory bowel disease [IBD] diagnosed in 1973–2013, matched reference individuals, and siblings to patients with IBD
| Characteristic | IBD | Ulcerative colitis | Crohn’s disease | IBD-unclassified | Reference individuals | P value | Siblings of patients with IBD | P value |
|---|---|---|---|---|---|---|---|---|
| Total | 69 865 [100%] | 43 557 [100%] | 21 245 [100%] | 5063 [100%] | 3 472 913 [100%] | 66 292 [100%] | ||
| Male sex | 36 189 [51.8] | 23 546 [54.1] | 10 072 [47.4] | 2571 [50.8] | 1 795 908 [51.7] | 0.6534 | 33 851 [51.1] | 0.0489 |
| Female sex | 33 676 [48.2] | 20 011 [45.9] | 11 173 [52.6] | 2492 [49.2] | 1 677 005 [48.3] | 32 441 [48.9] | ||
| Country of birth | ||||||||
| Sweden | 62 904 [90.0] | 39 374 [90.4] | 18 991 [89.4] | 4539 [89.7] | 3 124 892 [90.0] | 0.6194 | 64 033 [96.6] | 0.0003 |
| Other | 6961 [10.0] | 4183 [9.6] | 2254 [10.6] | 524 [10.3] | 348 021 [10.0] | 2259 [3.4] | ||
| Level of education | ||||||||
| Compulsory school | 16 917 [24.2] | 10 364 [23.8] | 5288 [24.9] | 1265 [25.0] | 818 511 [23.6] | <0.0001 | 14 175 [21.4] | <0.0001 |
| Upper secondary 2 years | 18 596 [26.6] | 11 435 [26.3] | 5869 [27.6] | 1292 [25.5] | 872 127 [25.1] | 19 187 [28.9] | ||
| Upper secondary 3 years | 12 151 [17.4] | 7357 [16.9] | 3829 [18.0] | 965 [19.1] | 598 713 [17.2] | 12 241 [18.5] | ||
| University < 3 years | 8317 [11.9] | 5235 [12.0] | 2458 [11.6] | 624 [12.3] | 418 575 [12.1] | 8399 [12.7] | ||
| University ≥3 yearsd | 12 148 [17.4] | 8007 [18.4] | 3321 [15.6] | 820 [16.2] | 649 727 [18.7] | 11 730 [17.7] | ||
| Missing | 1736 [2.5] | 1159 [2.7] | 480 [2.3] | 97 [1.9] | 115 260 [3.3] | 560 [0.8] | ||
| Age at IBD diagnosis and/or cohort entry, years | ||||||||
| 18 to < 40 | 33 861 [48.5] | 20 109 [46.2] | 11 306 [53.2] | 2446 [48.3] | 1 691 846 [48.7] | 0.8811 | 37 895 [57.2] | <0.0001 |
| 40 to < 60 | 20 795 [29.8] | 13 466 [30.9] | 5915 [27.8] | 1414 [27.9] | 1 032 266 [29.7] | 22 032 [33.2] | ||
| ≥ 60 | 15 209 [21.8] | 9982 [22.9] | 4024 [18.9] | 1203 [23.8] | 748 801 [21.6] | 6365 [9.6] | ||
| Mean [SD] | 44.1 [17.9] | 45.0 [17.8] | 42.0 [17.8] | 44.5 [18.9] | 43.9 [17.9] | 0.1660 | 38.3 [14.9] | <0.0001 |
| Median [IQR] | 40.8 [28.8–57.5] | 42.1 [30.0–58.4] | 38.2 [26.7–55.2] | 41.0 [28.0–58.9] | 40.7 [28.7–57.4] | 36.8 [26.6–49.2] | ||
| Start year of follow-up, years | ||||||||
| 1973–1979 | 5657 [8.1] | 3130 [7.2] | 2190 [10.3] | 337 [6.7] | 282 643 [8.1] | 0.8811 | 4396 [6.6] | <0.0001 |
| 1980–1989 | 11 353 [16.2] | 6708 [15.4] | 3970 [18.7] | 675 [13.3] | 566 599 [16.3] | 10 843 [16.4] | ||
| 1990–1999 | 14 305 [20.5] | 9013 [20.7] | 4357 [20.5] | 935 [18.5] | 712 676 [20.5] | 13 410 [20.2] | ||
| 2000–2013 | 38 550 [55.2] | 24 706 [56.7] | 10 728 [50.5] | 3116 [61.5] | 1 910 995 [55.0] | 37 643 [56.8] | ||
| Version of ICD classification at the time of cohort entry | ||||||||
| ICD-8 [1973–1986] | 13 376 [19.1] | 7753 [17.8] | 4857 [22.9] | 766 [15.1] | 667 894 [19.2] | 0.7608 | 11 635 [17.6] | <0.0001 |
| ICD-9 [1987–1996] | 11 975 [17.1] | 6987 [16.0] | 4124 [19.4] | 864 [17.1] | 596 975 [17.2] | 11 225 [16.9] | ||
| ICD-10 [1997–2013] | 44 514 [63.7] | 28 817 [66.2] | 12 264 [57.7] | 3433 [67.8] | 2 208 044 [63.6] | 43 432 [65.5] | ||
| Source of data at the time of cohort entry | ||||||||
| Inpatient register [prior to 2002] | 38 817 [55.6] | 24 030 [55.2] | 12 490 [58.8] | 2297 [45.4] | 1 935 238 [55.7] | 0.3930 | 36 012 [54.3] | <0.0001 |
| Inpatient and outpatient registers[since 2002] | 31 048 [44.4] | 19 527 [44.8] | 8755 [41.2] | 2766 [54.6] | 1 537 675 [44.3] | 30 280 [45.7] | ||
| Age at the end of follow-up, years | ||||||||
| Mean [SD] | 56.8 [17.9] | 57.4 [17.7] | 55.8 [17.9] | 55.6 [18.5] | 57.3 [18.2] | <0.0001 | 52.5 [15.6] | <0.0001 |
| Median [IQR] | 57.3 [42.6–70.3] | 57.8 [43.3–70.8] | 56.4 [41.7–69.4] | 56.3 [40.6–69.5] | 57.7 [42.8–70.8] | 54.2 [41.2–65.1] | ||
| Reasons for end of follow-up | ||||||||
| Psychiatric diagnosis | 7465 [10.7] | 4313 [9.9] | 2605 [12.3] | 547 [10.8] | 306 911 [8.8] | <0.0001 | 5621 [8.5] | <0.0001 |
| Death | 10 718 [15.3] | 6866 [15.8] | 3190 [15.0] | 662 [13.1] | 440 866 [12.7] | 2269 [3.4] | ||
| Emigration | 1038 [1.5] | 630 [1.4] | 339 [1.6] | 69 [1.4] | 60 077 [1.7] | 1088 [1.6] | ||
| End of study | 50 644 [72.5] | 31 748 [72.9] | 15 111 [71.1] | 3785 [74.8] | 2 665 059 [76.7] | 57 314 [86.5] | ||
| Length of follow-up, years | ||||||||
| < 1 | 3743 [5.4] | 2213 [5.1] | 1137 [5.4] | 393 [7.8] | 127 881 [3.7] | <0.0001 | 2122 [3.2] | <0.0001 |
| 1 to < 5 | 14 159 [20.3] | 8539 [19.6] | 4123 [19.4] | 1497 [29.6] | 665 594 [19.2] | 11 541 [17.4] | ||
| 5 to < 10 | 15 037 [21.5] | 9779 [22.5] | 4236 [19.9] | 1022 [20.2] | 750 449 [21.6] | 13 521 [20.4] | ||
| ≥ 10 | 36,926 [52.9] | 23 026 [52.9] | 11 749 [55.3] | 2151 [42.5] | 1 928 989 [55.5] | 39 108 [59.0] | ||
| Mean [SD] | 12.7 [9.9] | 12.4 [9.4] | 13.8 [10.6] | 11.1 [10.1] | 13.3 [10.0] | 0.0094 | 14.2 [10.2] | <0.0001 |
| Median [IQR] | 10.8 [4.9–17.9] | 10.7 [5.1–16.7] | 11.4 [5.1–20.9] | 7.7 [3.2–16.6] | 11.3 [5.4–19.0] | 12.0 [6.0–20.6] | ||
| Complications during follow-up | ||||||||
| Extraintestinal manifestations | 8818 [12.6] | 4984 [11.4] | 3163 [14.9] | 671 [13.3] | ||||
| Primary sclerosing cholangitis | 2048 [2.9] | 1537 [3.5] | 355 [1.7] | 156 [3.1] | ||||
| IBD surgery | ||||||||
| Bowel surgery | 17 200 [24.6] | 8621 [19.8] | 7500 [35.3] | 1079 [21.3] | ||||
| Perianal surgery | 5691 [8.1] | 2402 [5.5] | 2854 [13.4] | 435 [8.6] | ||||
| Psychiatric diagnoses in first degree relatives | 27 672 [39.6] | 16 947 [38.9] | 8635 [40.6] | 2090 [41.3] | 1 322 730 [38.1] | <0.0001 | 33 409 [50.4] | <0.0001 |
| Psychiatric diagnoses in parents | 11 894 [17.0] | 7260 [16.7] | 3729 [17.6] | 905 [17.9] | 563 897 [16.2] | <0.0001 | 13 718 [20.7] | 0.7981 |
| Psychiatric diagnoses in siblings | 10 181 [14.6] | 6204 [14.2] | 3219 [15.2] | 758 [15.0] | 479 241 [13.8] | <0.0001 | 18 798 [28.4] | <0.0001 |
| Psychiatric diagnoses in children | 12 050 [17.2] | 7337 [16.8] | 3804 [17.9] | 909 [18.0] | 575 561 [16.6] | <0.0001 | 11 150 [16.8] | 0.4936 |