Is home peak expiratory flow monitoring effective for controlling asthma symptoms?

A case in which a home peak expiratory flow (PEF) monitoring device was recommended led us to review the evidence examining this intervention. The clinical question to be answered was: should these devices be consistently recommended to all patients with asthma? A comprehensive search revealed eight randomized controlled trials, one review and one consensus report. Four trials provided all subjects with asthma education and compared patient-specific action plans based on symptoms to those based on PEF readings. Four trials compared usual asthma care to peak flow monitoring (PFM) and varied in both their content and intensity of asthma education. Six out of eight studies showed improvement in some selected markers of asthma morbidity with home PFM-based action plans. Improvements were also observed in patients using a symptom-based action plan. These studies did not demonstrate any obvious advantage of PFM compared with symptom-based monitoring but did suggest that a monitoring plan with predetermined actions based on PEF measurements or symptoms can lead to improved asthma control. Although not specifically studied, PFM may be more appropriate and effective for patients who have difficulty identifying worsening of asthma control through symptom monitoring.