Asthma: a peak flow-based action plan reduced need for urgent treatment.

Clinical bottom line (level 1b)

  1. Patients who had acute asthma exacerbation who received subsequently a peak flow-based action plan had less requirement for further urgent treatment (NNT = 3 at 6 months) .
  2. A symptom-based plan was not clearly better than giving no advice at all (although the study was small).
Cowie et al: Chest 1997; 116: 1534-1538
Expires November 2002

The study

Unblinded concealed randomised trial with intention-to-treat
Setting: asthma clinic, university hospital, USA

150 patients (aged mean 37 years, 75% female) required urgent treatment of asthma within 12 months (defined as treatment to provide immediate relief of asthma symptoms perceived to be severe and that had failed to respond to subject's usual reliever medication- patients usually treated in an emergency department)

Excluded if
  • already had written asthma management plan


    • Control Group: (n = 51, 48 analysed): no action
    Experimental Group: (n = 50, 45 analysed): symptom-based action plan: walking at night, persistent cough, symptoms of common cold- double inhaled steroid dose; relief with bronchodilator lasting = 2 hours or short of breath during normal daily activities- prenisone course; relief with bronchodilator lasting = 30 minutes or breathing made speaking difficult- seek urgent treatment
    Experimental Group: (n = 48, 46 analysed): peak-flow based action plan: = 70% or = 20% diurnal variation- double inhaled steroid dose; = 50%- prednisone course; = - seek urgent treatment
    All patients completed a questionnaire and received individual instruction from a nurse clinician. All family physicians were contacted and advised on optimising treatment.
    93% followed for 6 months

    The evidence

    peak-flow based plan
    Outcome Time to outcome CEREERRRR
    (95% CI)    		ARR
    (95% CI)    		NNT
    (95% CI)
    urgent treatment 6 months 19
    (39.6%)    		 5
    (10.9%)    		 73%
    (33% to 89%)    		 28.7%
    (12.2% to 45.2%)    		 3
    (2 to 8)
    admitted 6 months 6
    (12.5%)    		 2
    (4.35%)    		 65%
    (-64% to 93%)    		 8.15%
    (-2.91% to 19.2%)    		 12
    (NNT = 5 to infinity;
    NNH = 34 to infinity)

    symptom-based plan
    Outcome Time to outcome CEREERRRR
    (95% CI)    		ARR
    (95% CI)    		NNT
    (95% CI)
    urgent treatment 6 months 19
    (39.6%)    		 14
    (31.1%)    		 21%
    (-37% to 55%)    		 8.47%
    (-10.9% to 27.8%)    		 12
    (NNT = 4 to infinity;
    NNH = 9 to infinity)
    admitted 6 months 6
    (12.5%)    		 2
    (4.44%)    		 64%
    (-67% to 92%)    		 8.06%
    (-3.07% to 19.2%)    		 12
    (NNT = 5 to infinity;
    NNH = 33 to infinity)

  • Total amounts of inhaled and oral steroids used did not differ between the treatment groups.

    • Comments

    1. The study is too small to convincingly demonstrate a lack of benefit from using the symptom based plan.
    2. It is not clear if both methods were picking-up the same level of severity - which may go towards explaining the differences
    3. Charlton et al demonstrated in an unblinded community-based study that both peak-flow and symptom based plans were probably as effective.

    Citation

    1. Cowie RL, Revitt SG, Underwood MF, et al: The effect of a peak flow-based action plan in the prevention of exacerbations of asthma. Chest 1997; 116: 1534-1538
    Search Terms: acute asthma in Cochrane
    Contributor: Chris Ball and Clare Wotton, June 2000
    Reviewer: Chris van Weel

    Clinical Question.
    Patient asthma
    Intervention or Exposure peak-flow or symptom based action plan
    Comparison no action
    Outcome admission, urgent treatment