Patient characteristics and diagnostic procedures within a nationwide cohort of patients diagnosed with IBD within the period of 2014–2018
| Total IBD population (N=12 871) | CD cases (N=4748) | UC cases (N=8123) | Female (N=6691) | Male (N=6180) | Child (N=836) | Adult (N=12 035) | |
| Median age at the date of the first IBD hospital admission (years), median (IQR) | 40 (25–57) | 34 (22–54) | 43 (28–59) | 39 (25–58) | 40 (25–27) | 14 (11–15) | 42 (27–59) |
| Age group at date of first IBD hospital admission, n (%) | |||||||
| Children (<17 years) | 836 (6.5) | 453 (9.5) | 383 (4.7%) | 381 (5.7 | 455 (7.4) | 836 (100) | 0 (0) |
| Adults (17–60 years) | 9302 (72.3) | 3447 (72.6) | 5 855 (72.1%) | 4876 (72.9) | 4426 (71.6) | 0 (0) | 9302 (77.3) |
| Elderly (>60 years) | 2733 (21.2) | 848 (17.9) | 1885 (23.2) | 1434 (21.4) | 1299 (21.0) | 0 (0%) | 2733 (22.7) |
| Sex, n (%) | |||||||
| Female | 6691 (52.0) | 2565 (54.0) | 4126 (50.8) | 6691 (100) | 0 (0) | 381 (45.6) | 6310 (52.4) |
| Type of IBD, n (%) | |||||||
| CD | 4748 (36.9) | 4748 (100) | 0 (0) | 2565 (38.3) | 2183 (35.3) | 453 (54.2) | 4295 (35.7) |
| UC | 8123 (63.1) | 0 (0) | 8123 (100) | 4126 (61.7) | 3997 (64.7) | 383 (45.8) | 7740 (64.3) |
| A history of previous other gastrointestinal-related hospital admissions,* n (%) | 4599 (35.7) | 2088 (44.0) | 2511 (30.9) | 2477 (37.0) | 2122 34.3) | 383 (45.8) | 4216 (35.0) |
| At least one diagnostic procedure,†‡ n (%) | 11 903 (92.5) | 4451 (93.7) | 7452 (91.7) | 6120 (91.5) | 5783 (93.6) | 766 (91.6) | 11 137 (92.5) |
| Diagnostic procedures, †‡ n (%) | |||||||
| Endoscopy | 10 814 (84.0) | 4058 (85.5) | 6756 (83.2) | 5556 (83.0) | 5258 (85.1) | 707 (84.6) | 10 107 (84.0) |
| Gastroscopy (upper, including esophagus scopy) | 2014 (15.6) | 1231 (25.9) | 783 (9.6) | 1079 (16.1) | 935 (15.1) | 518 (62.0) | 1496 (12.4) |
| Enteroscopy or colonoscopy (including sigmoidoscopy) | 10 535 (81.9) | 3868 (81.5) | 6667 (82.1) | 5410 (80.9) | 5125 (82.9) | 677 (81.0) | 9858 (81.9) |
| Capsule endoscopy | 869 (6.8) | 752 (15.8) | 117 (1.4) | 494 (7.4) | 375 (6.1) | 59 (7.1) | 810 (6.7) |
| Imaging | 5647 (43.9) | 3290 (69.3) | 2357 (29.0) | 2968 (44.4) | 2679 (43.3) | 531 (63.5) | 5116 (42.5) |
| MR scan | 2823 (21.9) | 2069 (43.6) | 754 (9.3) | 1486 (22.2) | 1337 (21.6) | 406 (48.6) | 2417 (20.1) |
| CT scan | 2984 (23.2) | 1630 (34.3) | 1354 (16.7) | 1528 (22.8) | 1456 (23.6) | 59 (7.1) | 2925 (24.3) |
| Ultrasound | 2161 (16.8) | 1293 (27.2) | 868 (10.7) | 1202 (18.0) | 959 (15.5) | 269 (32.2) | 1892 (15.7) |
| Gastrointestinal biopsy§ ¶ | 10 856 (84.3 | 3863 (81.4) | 6993 (86.1) | 5529 (82.6) | 5327 (86.2) | 695 (83.1) | 10 161 (84.4) |
| DNPR registration | 9042 (70.3) | 3316 (69.8) | 5726 (70.5) | 4614 (69.0) | 4428 (71.7) | 616 (73.7) | 8426 (70.0) |
| DPR registration | 9744 (75.7) | 3225 (67.9) | 6519 (80.3) | 4914 (73.4) | 4830 (78.2) | 660 (78.9) | 9084 (75.5) |
'N' represents 'total sample' and 'n' represents 'subsample'.
*IBD cases with a history of previous hospital admissions with other gastrointestinal diagnostic codes than IBD within 365 days before he date of the first hospital admission: (R10–R19), (K26), (K52), (K55–K64), and (K90–K93).
†Within the period: 180 days before or after the admission date of the first IBD hospital admission.
‡All percentages are out of total number of patients (N (total population)=12 871 (N (CD)=4748, N (UC)=8123; N (women)=6691, N (men)=6180; N (children)=836, N (adults)=12 035)). Patients may be represented in more than one subgroup of each procedure type; therefore, percentages do not sum to 100%.
§The date of requisition of a biopsy may differ by several days from the date where the endoscopic procedures have been performed. This may explain why the proportion of gastrointestinal biopsies was higher than the proportion of endoscopies.
¶Biopsies taken by a private practising gastroenterologist are registered in the DPR but not in the DNPR, explaining why more biopsies are identified in the DPR compared with the DNPR. A biopsy-taking endoscopy registered in the DNPR should as a rule match a registration of examination of a biopsy in the DPR. For 16.7% of endoscopies with biopsies registered in the DNPR, no corresponding match could be identified in the DPR, indicating that these procedures in the DNPR may have been incorrectly registered.
.CD, Crohn’s disease; DNPR, Danish National Patient Register; DPR, Danish Pathology Register; IBD, inflammatory bowel disease; UC, ulcerative colitis.