Reference values for peak expiratory flow rate in adults of African descent.

Substantial racial differences in the values of peak expiratory flow (PEF) rate have been noted by several workers in the past. It has also been noted that applying prediction formulae derived from a Caucasian population overestimated the PEF values in Black Africans by 12%-15%. Yet reference values used up until the present, even among Black populations, are based on such formulae. This study provides new reference values for use in the Black population. They were obtained by using curvilinear formulae derived from the study of 1009 normal adult Nigerians (668 men and 341 women) between the ages of 15 years and 82 years, living and/or working in Port Harcourt, Nigeria and its hinterland.