Abstract
An epidemiological survey of 1239 normal subjects without respiratory symptoms was undertaken in an urban locality of New Delhi, India in 1974. The subjects were divided into males aged under or over 22 yr and females under or over 17 yr. Various statistical models were calculated to relate peak expiratory flow rate to the age, height and weight of the subjects in each group. The linear model was simple, convenient and adequately explained the variation in peak expiratory flow rate.