Patient demographics and clinical characteristics
| Demographic variable | Frequency (%) |
| Gender | |
| Female | 21 (67.7) |
| Male | 10 (32.3) |
| Race | |
| Caucasian | 19 (61.3) |
| African–American | 8 (25.8) |
| Other | 4 (12.9) |
| Smoking status | |
| Never | 20 (64.5) |
| Former | 8 (25.8) |
| Current | 3 (9.7) |
| BMI (mean) (SD) | 25.5±5.7 |
| Age at ustekinumab induction in years (median) (IQR) | 36 (27–43) |
| Duration of the disease at time of induction in years (median) (IQR) | 12.5 (5.3–18.5) |
| Montreal classification—disease location | |
| L1—ileal | 2 (6.5) |
| L2—colonic | 15 (48.4) |
| L3—ileocolonic | 11 (35.5) |
| L4—upper disease | 1 (3.2) |
| J pouch | 2 (6.5) |
| Montreal classification—behaviour of the disease, n (%) | |
| B1—non-stricturing, non-penetrating | 15 (48.4) |
| B2—stricturing | 3 (9.7) |
| B3—penetrating | 13 (41.9) |
| Previous history of perianal surgery | 19 (61.3) |
| Seton placement | 9 (29) |
| Fistulotomy | 4 (12.9) |
| Abscess drainage | 2 (6.5) |
| Fistulectomy | 2 (6.5) |
| Advancement flap | 1 (3.2) |
| Unknown | 1 (3.2) |
| Intestinal resection prior to induction | 13 (41.9) |
| Current seton at time of ustekinumab induction | 8 (25.8) |
| Concurrent immunomodulators at induction | 10 (32.6) |
| Previous use of immunomodulators | |
| Azathioprine | 17 (54.8) |
| Methotrexate | 7 (22.6) |
| 6-mercaptopurine | 6 (19.4) |
| Prior biological exposure | |
| Infliximab | 25 (80.6) |
| Adalimumab | 25 (80.6) |
| Vedolizumab | 10 (32.3) |
| Certolizumab pegol | 6 (19.4) |
| Golimumab | 1 (3.2) |