ABSTRACT
Background: Over the past 6 years we have adapted the techniques of statistical process control (SPC) to the daily monitoring of peak expiratory flow rate (PEFR) and/or FEV1 in the care of patients with asthma. The primary
statistical tool is the Individual Value and Moving Range Chart (XmR
chart), which integrates knowledge of the serial AM PEFR pre-bronchodi-
lator values and their day-to-day variation together in a manner that enables
the physician and the patient to make more informed decisions. This article
introduces our adaptation of this statistical technique: the Functional Beha-
vior Chart, so named because each chart provides insights into the function
over time the system of care being monitored is capable of delivering. Case examples are provided.
