The maximal expiratory flow/volume curve in 197 healthy New Zealanders: a comparison with recent American standards.

Maximal expiratory flow/volume curves were recorded from 155 healthy, non-smoking Europeans aged seven to 71 yr and 42 Polynesian children aged nine to 11 yr. Forced vital capacity (FVC), forced expiratory volume in 1s (FEV1), FEV1/FVC, peak expiratory flow (PEF) and flow at 50 and 25% of FVC (V50 and V25) were compared with the predictions made from the equations of Schoenberg, Beck and Bouhuys, describing healthy people in Connecticut, USA. In general the equations described our subjects well; the small but significant discrepancies may reflect either technical factors or possibly a true difference in populations.