Baseline characteristics of the 229 participants
| Characteristics | n (%) |
| Female sex | 158 (69.0) |
| Age, median ±IQR (years) | 38.0±17 |
| Ethnicity (n=226) | |
| Caucasian | 200 (88.5) |
| Non-Caucasian | 26 (11.5) |
| Current smoker | 29 (12.7) |
| Education* (n=226) | |
| Low | 41 (18.1) |
| Moderate | 83 (36.7) |
| High | 102 (45.1) |
| Employment status† | |
| Employed | 153 (66.8) |
| Unemployed | 8 (3.5) |
| Occupational disability | 39 (17.3) |
| Pensioner | 17 (7.4) |
| Student | 14 (6.1) |
| Crohn’s disease | 155 (67.7) |
| Age at diagnosis | |
| <16 years | 38 (24.5) |
| 17–40 years | 107 (69.0) |
| >40 years | 10 (6.5) |
| Disease location | |
| Ileitis | 29 (18.7) |
| Colitis | 22 (14.2) |
| Ileocolitis | 104 (67.1) |
| Upper gastrointestinal disease | 17 (11.0) |
| Disease behaviour | |
| Luminal disease | 66 (42.6) |
| Stricturing disease | 56 (36.1) |
| Penetrating disease | 48 (31.0) |
| Perianal involvement | 39 (25.2) |
| Ulcerative colitis | 66 (28.8) |
| IBD-U | 8 (3.5) |
| Disease extent‡ | |
| Proctitis | 6 (8.1) |
| Left sided colitis | 19 (25.7) |
| Pancolitis | 49 (66.2) |
| Previous IBD-related surgery | 104 (45.4) |
| Stoma | 24 (10.5) |
| Pouch | 13 (5.7) |
| IBD Medication | |
| None | 35 (15.3) |
| Aminosalicylates | 54 (23.6) |
| Corticosteroid | 46 (20.1) |
| Immunomodulator§ | 40 (17.5) |
| Tofacitinib | 4 (1.7) |
| Biological | 119 (52.0) |
| Anti-TNF | 76 (33.2) |
| Vedolizumab | 17 (7.4) |
| Ustekinumab | 22 (9.6) |
*Education status based on the Dutch Central Bureau of Statistics (low=high school and primary school education, moderate=middle-level applied education, high=higher professional education, scientific education (and/or doctorate).
†Multiple answers were available.
‡IBD-U included.
§Immunomodulator use included thiopurines and methotrexate.
IBD-U, inflammatory bowel disease unclassified; TNF, tumour necrosis factor.