Alemi Farrokh, Neuhauser Duncan
College of Nursing and Health Science, George Mason University, Fairfax, Virginia, USA.
Jt Comm J Qual Saf. 2004 Feb;30(2):95-102. doi: 10.1016/s1549-3741(04)30011-0.
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.
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.
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.
监测呼气峰值流速（PEFR）对于有效管理哮喘至关重要。建议每日监测PEFR，但患者很少使用这些数据来了解自身病情进展，临床医生也很少据此修改治疗方案。时间间隔控制图已被证明特别适用于监测罕见事件，可用于监测哮喘发作。
要求每位患者每天记录一次其PEFR值，并使用这些数据构建控制图。展示了三个先前报告病例的PEFR数据，并用于说明控制图方法。如果绘制连续发作的持续时间，且观察到的持续时间超过控制上限（UCL），则患者病情恶化。如果绘制连续无症状天数的长度，且观察到的持续时间超过UCL，则患者病情好转。在这两种情况下，临床医生和患者都要探究导致恢复延长或病情恶化的原因。目的是延长到下一次发作的时间。
使用时间间隔控制图监测哮喘发作具有以下优势：可直观展示数据，与观察趋势不同，它能明确患者何时应寻求更多临床建议。控制限使临床医生和患者能够忽略随机变化，专注于哮喘发作潜在模式的实际变化。
