Skip to main content

Time-Between Control Charts for Monitoring Asthma Attacks

Buy Article:

$12.00 plus tax (Refund Policy)


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.

Document Type: Research Article

Publication date: 2004-02-01

More about this publication?
  • The Joint Commission Journal on Quality and Patient Safety will be published by Elsevier beginning in 2017! For readers who receive access to the journal through their institutions, the journal can now be found on ScienceDirect ( For librarians looking to subscribe to the journal for their institutions please contact your Elsevier Account Manager or visit for more information. All other readers, please visit to subscribe to the journal or to claim your access for an existing subscription.
  • Editorial Board
  • Information for Authors
  • Subscribe to this Title
  • Information for Advertisers
  • Reprints and Permissions
  • Index
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free ContentFree content
  • Partial Free ContentPartial Free content
  • New ContentNew content
  • Open Access ContentOpen access content
  • Partial Open Access ContentPartial Open access content
  • Subscribed ContentSubscribed content
  • Partial Subscribed ContentPartial Subscribed content
  • Free Trial ContentFree trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more