The Effect of a Peak Flow-Based Action Plan in the Prevention of Exacerbations

Study objective: To determine the effect of a symptom-based and a peak flow-based action plan in preventing acute exacerbations in subjects with poorly controlled asthma. Design: A randomized controlled trial in which subjects who had required urgent treatment for their asthma were allocated to receive no action plan, a symptom-based plan, or a peak flow-based action plan. Setting: A university hospital asthma clinic. Population: One hundred fifty subjects were recruited after attending an emergency department or a clinic for urgent treatment of asthma. Interventions: All subjects received evaluation and education for asthma before being randomly allocated to receive no action plan, a symptom-based action plan, or a peak flowmeter and a peak flow-based action plan. Measurements: Subjects were assessed by questionnaire at 3 and 6 months after enrollment with questions relating to their asthma control and their need for urgent treatment or hospital admission for asthma. Results: At 6 months after enrollment, although all three intervention groups experienced improvement in their asthma control, there was a striking reduction in emergency department visits for asthma only in the peak flow-based action plan group (p=0.006). No significant difference in emergency visits was apparent between the symptom-based action plan and no action plan groups. Conclusions: We conclude that a peak flow-based action plan is effective, at least in the short term, in protecting patients with asthma against severe exacerbations of their disease. (CHEST 1997; 112:1534-38)