Background/aims: Azathioprine is the most commonly used immunomodulator in Crohn's disease. The aims of the study are to determine the cumulative frequency of azathioprine prescription in non selected consecutive inpatients with Crohn's disease and to identify a subgroup of patients with high risk of azathioprine prescription during the follow-up.
Methodology: We studied consecutive in patients with established diagnosis of Crohn's disease admitted in our department in years 2002 and 2003. Cumulative frequency of azathioprine use during the follow-up was calculated. Predictive factors of azathioprine use were studies based on clinical, biological and endoscopic charts at the first hospitalization in our department.
Results: We include 88 patients (52 males, mean age 31.3 years (18 - 68)). Azathioprine was prescribed in 38 patients (43.2%) with a mean period of 12.9 months (1 - 90) after the first hospitalization. The cumulative frequency of azathioprine prescription was 11% the first month, 31% at 6 months, 35% at one year and 49% at 6 years. In univariate analysis, azathioprine use was more frequent in previously treated patients in an other department (p = 0.05), in case of ileal involvement > 40 cm (p = 0.02), previously treated patients with corticosteroids (p = 0.001), first treatment in our unit by corticosteroids (p < 0.0001), duration of the flare more than 6 months (p = 0.01), CDAI > 204 points (p < 0.0001), Hemoglobin level < 9.7 g/ dl (p < 0.0001) and cholesterolemia level < 1.32 g/l (p < 0.0001). Independent factors associated with azathioprine use in our population were diffuse involvement of the ileum at initial hospitalization (p = 0.0001; OR [95%CI]: 17.9 [4.1-77.9]), and previous prescription of corticosteroid therapy (p = 0.04; OR [95% CI]: 5 [1.1-25]).
Conclusion: Azathioprine is frequently used in adult Crohn's disease patients, maximally within the first year after the first hospitalization. Patients with diffuse ileal involvement and previously treated patients with corticosteroids are at higher risk to azathioprine use and should have systematically the preventive strategies to ovoid opportunistic infections since their first visit.