PEFR monitoring in asthma

Last reviewed 01/2018

The measurement of peak expiratory flow rate (PEFR) three to four times per day allows the diagnosis and assessment of the severity of asthma.

Untreated asthma is characterised by:

  • greater than 10% diurnal variability in PEFR
  • lowest values in the morning

A diagnostic trial of oral corticosteroids should show an upward trend in the mean PEFR in asthma.