Asthma: acute exacerbations: steroids prevent relapse.

Clinical bottom line (level 1a)

  1. Patients who are discharged on a short course of steroids from emergency departments following treatment for acute asthma exacerbations are less likely to relapse (NNT = 4 at 21 days) or be admitted to hospital (NNT = 11 at 21 days) .
  2. Patients use less beta-agonists, and do not clearly have more side effects.
  3. Intramuscular steroids may be as effective as oral steroids.
Rowe et al: The Cochrane Library, Issue 3, 1998. Oxford: Update 2000; 4: -
Expires November 2002

The study

Systematic review of randomised controlled trials of
  • Patients: adults or children discharged from an acute care setting (usually emergency department) after assessment and treatment of an acute asthmatic exacerbation
  • Intervention: steroids for 3 to 10 days compared with placebo
  • Outcome: relapse rate or pulmonary function tests


    • Articles found in all using Cochrane Airways Group, ? dates (search terms: asthma and wheez* and RCT ) and bibliographies were also searched, authors and experts contacted for unpublished studies or other relevant articles

    Selection criteria: as above
    Appraisal criteria: selected and appraised by two independent blinded reviewers using set criteria (detailed in text)
    Articles excluded if: not stated

    Seven studies were found- two studies used intramuscular corticosteroids, five studies used oral corticosteroids
    The studies were not significantly heterogeneous, except for reporting of side effects.

    The evidence

    Outcome Time to outcome CER OR
    (95% CI)    		 NNT
    (95% CI)
    relapse 7 days 28/171
    (16%)    		 0.35
    (0.18 to 0.69)     		10
    (8 to 23)
    relapse 21 days 20/45
    (44%)    		 0.34
    (0.14 to 0.82)     		4
    (3 to 21)
    side effects 21 days 15/60
    (25%)    		 0.94
    (0.43 to 2.13)     		88
    (NNT = 8 to infinity;
    NNH = 6 to infinity)
    admission to hospital 21 days 14/99
    (14%)    		 0.34
    (0.13 to 0.89)     		11
    (8 to 74)
    oral vs intramuscular steroids: relapse 7-10 days 2/29
    (6.9%)    		 0.62
    (0.06 to 6.13)     		40
    (NNT = 15 to infinity;
    NNH = 4 to infinity)

    • beta-agonist use/day: weighted mean difference -3.3 (95% CI: -5.6 to -1.0)
    • change in pulmonary function test: mean difference 0.045 (95% CI: -0.47 to 0.56)

    Comments

    1. The Cochrane Airways Review Group (ARG) has developed a 'asthma and wheez* RCT' register through a comprehensive search of EMBASE, MEDLINE and CINAHL. In addition, hand searching of the top twenty respiratory care journals has been completed and relevant RCTs have been added to the register. This register contains a variety of studies published in foreign languages- trials were not excluded on the basis of language.
    2. Patients generally required less than 80% predicted PEFR or FEV1 to be eligible for inclusion in the trials.
    3. Different co-interventions were provided in each study, including theophylline, beta-agonists and anticholinergics.
    4. Due to the small number of trials included in this meta-analysis and the overall small number of patients upon which these results are based, no firm conclusions regarding subgroups by severity or age can be made.
    5. There is to be an NHLBI symposium on the question and hope to develop a large RCT.

    Citation

    1. Rowe BH, Spooner CH, Ducharme FM, et al: The effectiveness of corticosteroids in the treatment of acute exacerbations of asthma: a meta-analytic of their effect on relapse following acute assessment (Cochrane Review). The Cochrane Library, Issue 3, 1998. Oxford: Update 2000; 4: -
    Search Terms: acute asthma in Cochrane
    Contributor: Chris Ball and Clare Wotton, June 2000
    Reviewer: Gerard Ryan

    Clinical Question.
    Patient asthma exacerbation
    Intervention or Exposure corticosteroids
    Comparison placebo
    Outcome relapse