Using quality-control analysis of peak expiratory flow recordings to guide therapy for asthma

Ann Intern Med. 1995 Oct 1;123(7):488-92. doi: 10.7326/0003-4819-123-7-199510010-00002.


Objective: To compare the action points in published asthma management plans with those derived from quality-control analysis of peak expiratory flow recordings.

Design: Longitudinal observational study.

Setting: An ambulatory asthma education and management program in a tertiary care hospital.

Patients: 35 adults with asthma and exacerbation of asthma.

Measurements: Peak expiratory flow diaries and symptom recordings.

Results: Asthma action points from published asthma management guidelines had poor operating characteristics. The success rate was 35% when the action point was a peak expiratory flow rate less than 60% of the patient's best peak flow. The success rate improved to 88% when the action point was a peak expiratory flow rate less than 80% of the patient's best peak flow. Published action points had a high failure rate. Peak flow decreased to below the published action points during a stable period of asthma in 7% to 51% of patients studied. Action points defined using quality-control analysis did significantly better. A peak flow value less than 3 standard deviations below the patient's mean peak flow detected 84% of exacerbations and had a low failure rate (19%). Other quality-control tests had sensitivities of 91% and 71%. Quality-control action points could detect exacerbations up to 4.5 days earlier than conventional methods.

Conclusions: Individualized action points can be derived for patients with asthma by applying quality-control analysis to peak flow recordings. These action points are more sensitive in detecting exacerbations of asthma and have fewer false-positive results. Action plans developed in this manner should be more useful for the early detection of deteriorating asthma.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenal Cortex Hormones / therapeutic use
  • Adult
  • Asthma / diagnosis
  • Asthma / drug therapy*
  • Asthma / physiopathology
  • Bronchodilator Agents / therapeutic use
  • Drug Therapy, Combination
  • Female
  • Humans
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Peak Expiratory Flow Rate / physiology*
  • Practice Guidelines as Topic / standards
  • Quality Control
  • Sensitivity and Specificity


  • Adrenal Cortex Hormones
  • Bronchodilator Agents