Table 1.
Demographics of study population.
| Variable | All n (%) or median (IQR) |
Primary analysis cohort n (%) or median (IQR) |
|
|---|---|---|---|
| Sex | Female | 627/968 (64.8%) | 581/895 (64.9%) |
| Age at calprotectin/years | 33.3 (25.7–41.0) | 33.1 (25.6–40.7) | |
| Smoking status at calprotectin | Current | 204/641 (31.8%) | 183/594 (30.8%) |
| Ex | 72/641 (11.2%) | 68/594 (11.4%) | |
| Never | 365/641 (56.9%) | 343/594 (57.7%) | |
| Unknown | 327/968 (33.8%) | 301/895 (33.6%) | |
| Drugs at calprotectin | NSAIDS | 22/769 (2.9%) | 0/701 (0.0%) |
| Antibiotics | 50/769 (6.5%) | 0/701 (0.0%) | |
| Laxatives | 16/769 (2.1%) | 12/701 (1.7%) | |
| Opiates | 39/769 (5.1%) | 38/701 (5.4%) | |
| Immunosuppressants | 82/769 (10.7%) | 61/701 (8.7%) | |
| Loperamide | 6/769 (0.8%) | 2/701 (0.3%) | |
| Aminosalicylates | 47/769 (6.1%) | 42/701 (6.0%) | |
| Acetaminophen | 1/769 (0.1%) | 0/701 (0.0%) | |
| Aspirin | 73/769 (9.5%) | 52/701 (7.4%) | |
| Corticosteroids | 2/769 (0.3%) | 0/701 (0.0%) | |
| Unknown | 199/968 (20.6%) | 194/895 (21.7%) | |
| Family history | Nonea | 862/968 (89.0%) | 794/895 (88.7%) |
| UC | 22/968 (2.3%) | 21/895 (2.3%) | |
| CD | 27/968 (2.8%) | 26/895 (2.9%) | |
| IBDU | 63/968 (6.5%) | 60/895 (6.7%) | |
| Coeliac disease | 11/968 (1.1%) | 11/895 (1.2%) | |
| Colon cancer | 14/968 (1.4%) | 13/895 (1.5%) | |
| Previous medical history | Nonea | 920/968 (95.0%) | 868/895 (97.0%) |
| Inflammatory disease (non-gastrointestinal) | 30/968 (3.1%) | 24/895 (2.7%) | |
| Ankylosing spondylitis | 30/968 (3.1%) | 24/895 (2.7%) | |
| HIV | 3/968 (0.3%) | 2/895 (0.2%) | |
| Alcoholic liver disease | 9/968 (0.9%) | 0/895 (0.0%) | |
| Severe intercurrent illness | 6/968 (0.6%) | 1/895 (0.1%) |
NSAIDS: non-steroidal anti-inflammatory drugs; UC: ulcerative colitis; CD: Crohn's disease; IBDU: inflammatory bowel disease unclassified.a
It has been assumed for this table that in the absence of any recorded previous medical history or family history in the patient records that there is none.