Ventilatory functions of normal children and young adults--Mexican-American, white, and black. II. Wright peak flowmeter.

A study was undertaken to establish the normal values of peak expiratory flow rate using the WPFM in three ethnic groups. This report is based on the testing of 1,805 healthy students 7 to 20 years of age in the Houston public schools. Significant differences of WPFR are noted among the three races, and between boys and girls. Prediction equations and regression lines are presented for each sex/race group. The performance of the WPFM is compared with that of the spirometer.