Time-between control charts for monitoring asthma attacks.

BACKGROUND The monitoring of peak expiratory flow rate (PEFR) is crucial for effective management of asthma. Daily PEFR monitoring is recommended, yet the data are rarely used by patients to help them understand their progress or by clinicians to modify treatment plans. Time-between control charts, which have been shown to be specially suited for monitoring rare events, can be used to monitor asthma attacks. METHODS Each patient is asked to record his or her PEFR value once a day, and these data are used to construct the control chart. PEFR data for three previously reported cases are presented and used to illustrate the control chart methodology. If duration of consecutive attacks is plotted and the observed duration exceeds the upper control limit (UCL), the patient is getting worse. If length of consecutive symptom-free days is plotted and the observed duration exceeds the UCL, the patient is getting better. In both circumstances, the clinician and the patient explore what brought about the prolonged recovery or periods of deterioration. The object is to increase time until the next attack. DISCUSSION Using time-between control charts in monitoring asthma attacks has the advantage of providing a visual display of data that, unlike eyeballing of trends, clarifies when patients should seek additional clinical advice. The control limit allows clinicians and patients to ignore random variations and focus on real changes in underlying patterns of asthma attacks.

[1]  William Feller,et al.  An Introduction to Probability Theory and Its Applications , 1967 .

[2]  C. Solodky,et al.  Patients as partners in clinical research: a proposal for applying quality improvement methods to patient care. , 1998, Medical care.

[3]  J C Benneyan,et al.  Number-Between g-Type Statistical Quality Control Charts for Monitoring Adverse Events , 2001, Health care management science.

[4]  J C Benneyan,et al.  Performance of Number-Between g-Type Statistical Control Charts for Monitoring Adverse Events , 2001, Health care management science.

[5]  Lung,et al.  National asthma education program expert panel report. Guidelines for the diagnosis and management of asthma , 1991 .

[6]  Partridge,et al.  International Consensus Report on Diagnosis and Treatment of Asthma. , 1992, Clinical and experimental allergy : journal of the British Society for Allergy and Clinical Immunology.

[7]  Benjamin M. Adams,et al.  Advanced Topics in Statistical Process Control : The Power of Shewhart's Charts , 1995 .

[8]  John Wlodarczyk,et al.  Using Quality-Control Analysis of Peak Expiratory Flow Recordings To Guide Therapy for Asthma , 1995, Annals of Internal Medicine.

[9]  P B Boggs,et al.  Peak expiratory flow rate control chart in asthma care: chart construction and use in asthma care. , 1998, Annals of allergy, asthma & immunology : official publication of the American College of Allergy, Asthma, & Immunology.

[10]  P B Boggs,et al.  Using statistical process control charts for the continual improvement of asthma care. , 1999, The Joint Commission journal on quality improvement.

[11]  D. Neuhauser,et al.  Asthma health status. Ongoing measurement in the context of continuous quality improvement. , 1993, Medical care.

[12]  M. Pierce-Bulger,et al.  Nutaqsiivik--an approach to reducing infant mortality using quality improvement principles. , 2001, Quality management in health care.