Crohn's disease: mesalamine helps maintain remission

Clinical bottom line (level 1a)

  1. Patients with Crohn's disease in remission who take mesalamine compared with placebo or nothing are less likely to have a symptomatic relapse (NNT = 16 at 2 years) .
  2. Patients who take mesalamine following surgery are less likely to have a symptomatic relapse (NNT = 8 at 2 years) .
  3. There is no clear benefit for patients on medical therapy.
Camma et al: Gastroenterology 1997; 113: 1465-1473
Expires May 2003

The study

Systematic review of all randomised controlled trials of
  • Patients: Crohn's disease in remission (CDAI < 150)
  • Intervention: mesalamine compared with placebo or no treatment
  • Outcome: symptomatic relapse (CDAI > 150, or an increase of 60 to 100 points)


    • Articles found in all languages using Medline, 1986 to 1997 (search terms: Crohn's disease, 5-aminosalicyclic acid, mesalamine or mesalazine ) and and searching reference lists of review articles, primary studies, and congress abstracts

    Selection criteria: see above
    Appraisal criteria: using set criteria (detailed in text) by 3 independent reviewers
    Articles excluded if:
    • patients aged < 18
    • crude rates of symptomatic relapse not provided
    • compared mesalamine with 4-aminosalicylic acid
    • number of treated or untreated patients not reported
    • an intention-to-treat analysis not possible


    15 studies found involving 2097 patients (411 following surgery, 1371 having medical treatment) followed for 12 to 48 months.
    Studies were not found to be heterogenous.

    The evidence

    Outcome Time to outcome ARR
    (95% CI)    		NNT
    (95% CI)
    symptomatic relapse 2 years 6.3%
    (2.1% to 10.4%)    		 16
    (9 to 48)
    symptomatic relapse post-surgery 2 years 13.1%
    (4.5% to 21.8%)    		 8
    (5 to 22)
    symptomatic relapse in medical cases 2 years 4.7%
    (-2.8% to 9.6%)    		 21
    (NNT = 10 to infinity;
    NNH = 36 to infinity)

    Comments

    1. There was no clear difference between mesalamine and placebo for the number of patients stopping medication due to adverse effects.
    2. A multivariate regression analysis adjusting for confounders suggested the following reduce the probability of symptomatic relapse
      • mesalamine use
      • ileal disease
      • prolonged disease duration
      • surgically-induced remission
    3. Further studies, more detailed subgroup analyses, may provide more precise information in this field.

    Citation

    1. Camma C, Giunta M, Rosselli M, et al: mesalamine in the maintenance treatment of Crohn's disease: a meta-analysis adjusted for confounding variables. Gastroenterology 1997; 113: 1465-1473
    Search Terms: Crohn* in Cochrane
    Contributor: Chris Ball and Clare Wotton, October 1999
    Reviewer: Zoltan Bodnar

    Clinical Question.
    Patient Crohn's disease in remission
    Intervention or Exposure mesalamine
    Comparison placebo or no treatment
    Outcome symptomatic relapse