TABLE 3.
Cox regression analysis of factors affecting time to thiopurine monotherapy failure in CD patients
| Adjusted HR [95% CI] | p | |
|---|---|---|
| Age at thiopurine initiation | 0.99 [0.98–1.00] | 0.048* |
| Era of treatment initiation | ||
| 1991–1998 | REF | |
| 1999–2011 | 0.80 [0.57–1.14] | 0.22 |
| Time between diagnosis and start thiopurine in years | 0.96 [0.91–1.01] | 0.79 |
| Smoking at diagnosis | 1.29 [0.99–1.67] | 0.056 |
| Disease location at diagnosis a | ||
| L1: ileal | REF | |
| L2: ileocolonic | 0.92 [0.65–1.30] | 0.63 |
| L3: colonic | 1.26 [0.91–1.75] | 0.17 |
| Disease behaviour at diagnosis a | ||
| B1: inflammatory | REF | |
| B2: stricturing | 1.42 [1.01–1.99] | 0.044* |
| B3: penetrating | 1.26 [0.76–2.11] | 0.37 |
| Upper GI involvement at diagnosis | 1.53 [1.02–2.28] | 0.040* |
| Perianal disease at diagnosis | 1.34 [0.90–2.00] | 0.15 |
| First thiopurine type | ||
| AZA | REF | |
| 6‐MP/6‐TG | 1.01 [0.73–1.39] | 0.95 |
| Gender, female | 1.18 [0.88–1.59] | 0.28 |
Abbreviations: 6‐MP, 6‐mercaptopurine; 6‐TG, 6‐thioguanine; AZA, azathioprine; CD, Crohn's disease; CI, confidence interval; HR, Hazard ratio; p, p value; REF, reference category.
a
Disease location and behaviour based on Montreal Classification.
*
Significant p < 0.05.