Objectives: The primary objective was to precisely derive an estimate of the efficacy of oral budesonide for the maintenance of remission in Crohn's disease.
Search strategy: Medline 1966-September 2000 was searched using the text and key words "oral budesonide", "Crohn's disease", "Crohn disease", and "inflammatory bowel disease". Proceedings from the American Gastroenterology Association conference (1980-1998) were hand searched. Additionally, the Cochrane Controlled Trials Register and the Inflammatory Bowel Disease Review Group Trials Registers were also searched. The manufacturer of oral budesonide was also contacted, as were some of the local trialists involved in the oral budesonide trials. Relevant articles were retrieved, and their reference lists were also reviewed.
Selection criteria: Randomized controlled trials of oral budesonide in which patients at entry were in remission with a Crohn's Disease Activity Index (CDAI) <= 150, and had disease restricted to the ileum and colon.
Data collection and analysis: The primary outcome was the relative risk (RR) of relapse (and 95% confidence interval [CI]) during the 12 months of treatment, as defined by the number of patients who relapsed, and the number of patients who entered the trial. The numbers needed to treat were also derived.
Main results: Three randomized controlled trials of oral budesonide (controlled ileal release preparation) 6 mg/day, 3mg/day and placebo for a one year period were included in the analysis. Budesonide 6 mg/day was not effective at preventing relapse of Crohn's disease over the 12 months of treatment. The relative risk of relapse was 0.89 (95% CI: 0.71-1.13) comparing budesonide 6 mg/day and placebo. Similar results were also observed in the comparison of budesonide 6 mg/day with budesonide 3 mg/day; the relative risk of relapse was 0.89 (95% CI: 0.70-1.11). The 3 mg/day dose was similarly found to be ineffective at preventing relapse during the 12 months of treatment; the relative risk of relapse was 1.00 (95% CI: 0.80-1.24). The results of the analysis of relative risk of relapse were supported by the analysis of withdrawal due to treatment failure. The relative risks for withdrawal due to treatment failure for budesonide 6 mg/day compared with placebo was 0.85 (95% CI: 0.65-1.10), for budesonide 3 mg/day compared with placebo was 0.94 (95% CI: 0.73-1.20), and for budesonide 6 mg/day compared with budesonide 3 mg/day was 0.89 (95% CI: 0.68-1.17).
Reviewer's conclusions: Oral budesonide therapy at 6 mg/day is not effective in preventing relapses of Crohn's disease.