Effectiveness of 5-aminosalicylic acid for maintaining remission in patients with Crohn's disease: a meta-analysis.

OBJECTIVES We conducted a meta-analysis of the published randomized clinical trials to evaluate the effectiveness of 5-aminosalicylic acid (5-ASA) for maintaining remission in inactive Crohn's disease. METHODS The trials were identified by standard computerized techniques for literature search. All studies included in the meta-analysis were aimed at evaluating the effectiveness of 5-ASA in comparison with a control group receiving either no treatment or placebo. RESULTS Our meta-analysis of five clinical trials published as full-length articles indicates that 5-ASA significantly reduces the relapse frequency in patients with inactive Crohn's disease [odds-ratios (95% CI): 0.56 (0.37-0.84) at 6 months, 0.47 (0.33-0.67) at 12 months, 0.53 (0.38-0.73) at 24 months]. The pooled relapse-free rates in the treatment group were 91% at 6 months, 84% at 12 months, and 72% at 24 months; the corresponding rates in the control group were 77%, 60%, and 52%. A second meta-analysis, conducted using the additional information deriving from four randomized trials published as abstracts, gave essentially the same results. CONCLUSIONS Whereas our meta-analysis shows that the effectiveness of 5-ASA is statistically significant, a simple pharmacoeconomic assessment indicates that the cost for preventing each relapse can lie between $4,000 and $10,000. This cost compares favorably with the average cost for treating a relapse.