TABLE 1.
Baseline characteristics in the 1016 IBD patients who started on thiopurine monotherapy
| CD (n = 643/6092 PY) | UC (n = 373/3768 PY) | |
|---|---|---|
| Age at diagnosis in years, median [Q1‐Q3] | 32.5 [22.9–43.5] | 40.2 [29.8–53.6] |
| Era of diagnosis, n (%) | ||
| 1991–1998 | 146 (22.7) | 116 (31.1) |
| 1999–2005 | 239 (37.2) | 159 (42.6) |
| 2006–2011 | 258 (40.1) | 98 (26.3) |
| Time to thiopurine in months, median [Q1‐Q3] | 9.7 [3.2–38.8] | 28.2 [8.4–63.5] |
| Follow‐up in years, median [Q1‐Q3] | 8.5 [5.0–13.2] | 9.8 [5.8–14.6] |
| Thiopurine dose in mg/day a , median [Q1‐Q3] | ||
| Azathioprine | 125 [100–150] | 150 [100–150] |
| 6‐MP | 50 [50–62.5] | 50 [50–75] |
| 6‐TG | 20 [20–20] | 20 [20–20] |
| Gender, n (%) | ||
| Male | 232 (36.1) | 205 (55.0) |
| Female | 411 (63.9) | 168 (45.0) |
| Smoking at diagnosis b , n (%) | ||
| Yes | 307 (52.1) | |
| No | 282 (47.9) | |
| Disease location at diagnosis c , n (%) | ||
| UC | ||
| E1: proctitis | 78 (20.9) | |
| E2: left‐sided | 193 (51.7) | |
| E3: extensive | 102 (27.3) | |
| CD | ||
| L1: ileal | 265 (41.2) | |
| L2: colonic | 191 (29.7) | |
| L3: ileocolonic | 178 (27.7) | |
| L4: isolated upper GI disease | 9 (1.4) | |
| P: Perianal involvement | 55 (8.6) | |
| Disease behaviour at diagnosis c , n (%) | ||
| B1: non‐stricturing, non‐penetrating | 482 (75.0) | |
| B2: stricturing | 114 (17.7) | |
| B3: penetrating | 47 (7.3) | |
Abbreviations: CD, Crohn's disease; PY, patient years; n, number of patients; Q1‐Q3, quartile 1 and quartile 3; UC, ulcerative colitis.
a
Median dose of thiopurine monotherapy per mg/day, stratified for the type of thiopurine. Q1 and Q3 overlap with median in some instances due to the range of prescribed doses.
b
No data available on smoking status in UC patients, missing smoking data in 54 CD patients.
c
Phenotype at diagnosis according to Montreal Classification.