Lung functions with spirometry: an Indian perspective--I. Peak expiratory flow rates.

Peak expiratory flow rate is an effective measure of effort dependent airflow. It is relatively a simple procedure, and may be carried out in the field using portable instruments. The average PEFR of healthy young Indian males and females is around 500 and 350 lpm respectively. The PEFR reaches a peak at about 18-20 years, maintains this level up to about 30 years in males, and about 40 years in females, and then declines with age. Common regression equations for Indians enveloping major studies from various parts of the country have been formulated. Indian PEFR values compare favourably with other ethnic groups such as Americans and Europeans.