Table 1.
Main characteristics of COVID-19 inflammatory bowel disease patients in the study*
| Characteristics | Training data (n=2009) | Test data (n=700) | Overall (n=2709) |
| Age, mean (SD), years | 42.2 (18.2) | 38.7 (17.4) | 41.2 (18.0) |
| Gender, n (%) | |||
| Female | 982 (48.9%) | 344 (49.1%) | 1326 (48.9%) |
| Male | 998 (49.7%) | 341 (48.7%) | 1339 (49.4%) |
| Other | 1 (0.0%) | 0 (0.0%) | 1 (0.0%) |
| Asian†, n (%) | 112 (5.6%) | 38 (5.4%) | 150 (5.5%) |
| Black†, n (%) | 138 (6.9%) | 39 (5.6%) | 177 (6.5%) |
| White†, n (%) | 1603 (79.8%) | 547 (78.1%) | 2150 (79.4%) |
| Hispanic/Latino, n (%) | 350 (17.4%) | 115 (16.4%) | 465 (17.2%) |
| Missing | 375 (18.7%) | 120 (17.1%) | 495 (18.3%) |
| BMI, mean (SD) | 26.0 (6.50) | 25.2 (6.26) | 25.8 (6.44) |
| Missing | 398 (19.8%) | 106 (15.1%) | 504 (18.6%) |
| Current smoker, n (%) | 61 (3.0%) | 25 (3.6%) | 86 (3.2%) |
| Disease type, n (%) | |||
| Crohn’s disease | 1115 (55.5%) | 401 (57.3%) | 1516 (56.0%) |
| Ulcerative colitis | 854 (42.5%) | 278 (39.7%) | 1132 (41.8%) |
| Cardiovascular disease, n (%) | 133 (6.6%) | 43 (6.1%) | 176 (6.5%) |
| Diabetes, n (%) | 117 (5.8%) | 30 (4.3%) | 147 (5.4%) |
| Hypertension, n (%) | 243 (12.1%) | 67 (9.6%) | 310 (11.4%) |
| Count of comorbidities, mean (SD) | 0.544 (0.938) | 0.479 (0.879) | 0.527 (0.923) |
| Biological therapy, n (%) | 1203 (59.9%) | 437 (62.4%) | 1640 (60.5%) |
| Tumour necrosis factor inhibitor, n (%) | 796 (39.6%) | 313 (44.7%) | 1109 (40.9%) |
| Anti-integrin, n (%) | 213 (10.6%) | 72 (10.3%) | 285 (10.5%) |
| IL-12/23 inhibitor, n (%) | 187 (9.3%) | 47 (6.7%) | 234 (8.6%) |
| 5-Aminosalicylates, n (%) | 636 (31.7%) | 200 (28.6%) | 836 (30.9%) |
| Sulfasalazine, n (%) | 64 (3.2%) | 24 (3.4%) | 88 (3.2%) |
| Mesalamine, n (%) | 561 (27.9%) | 175 (25.0%) | 736 (27.2%) |
| Immunomodulators, n (%) | 459 (22.8%) | 140 (20.0%) | 599 (22.1%) |
| Methotrexate, n (%) | 81 (4.0%) | 24 (3.4%) | 105 (3.9%) |
| Azathioprine or 6-mercaptopurine, n (%) | 367 (18.3%) | 110 (15.7%) | 477 (17.6%) |
| Corticosteroids, n (%) | 209 (10.4%) | 65 (9.3%) | 274 (10.1%) |
| Budesonide, n (%) | 59 (2.9%) | 17 (2.4%) | 76 (2.8%) |
| Oral or parenteral steroids, n (%) | 154 (7.7%) | 49 (7.0%) | 203 (7.5%) |
| Janus kinase inhibitors (tofacitinib), n (%) | 30 (1.5%) | 9 (1.3%) | 39 (1.4%) |
| Hospitalisation+, n (%) | 499 (24.8%) | 138 (19.7%) | 637 (23.5%) |
| Missing | 37 (1.8%) | 17 (2.4%) | 54 (2.0%) |
| ICU+, n (%) | 133 (6.6%) | 36 (5.1%) | 169 (6.2%) |
| Missing | 49 (2.4%) | 22 (3.1%) | 71 (2.6%) |
| Death, n (%) | 57 (2.8%) | 12 (1.7%) | 69 (2.5%) |
| Missing | 33 (1.6%) | 14 (2.0%) | 47 (1.7%) |
*Missingness is only reported for predictors with >5% missing values, and for all outcomes. Only comorbidities with an overall prevalence above 5% are shown in this table. For a complete list of characteristics and number and percentage of missing values, see online supplemental table 3.
†Individuals can be assigned to more than one physician-reported racial group (white, black, Asian).
BMI, body mass index; ICU, intensive care unit; IL, interleukin.