Background Due to the presence of sources of air pollutants (multiple quarry sites and rice mills) in the study area, Peak Expiratory Flow Rate (PEFR) obtained in other parts of the country may not be safely extrapolated to this region. Additionally, the reality of the need to classify asthma exacerbations during emergencies or initial visits where a personal best PEFR is not available has made the development of local PEFR reference values paramount.

Objectives This study was undertaken to develop a nomogram of peak expiratory flow rate values for adolescents in Ebonyi State, Nigeria.

Methods A cross-sectional study was carried out among 970 adolescents from April to June 2018, using a multistage random sampling technique. The PEFR for each subject was determined by the standard miniWright peak flow meter. All data obtained were recorded in a proforma and analysed with Statistical Package for the Social Sciences version 21. The PEFR of the subjects were summarised using mean and standard deviation. Linear regression analysis was used to test the relationship between PEFR and its predictors.

Results The overall mean PEFR value was 332±83 L/min. The mean PEFR was 359±96 L/min in males and 312±64 L/min in females (t =9.09, p < 0.001). The predictive equation was derived as follows:

Males: PEFR = 2*Height + 7.8*Age + 1.7*Weight – 152.2

Females: PEFR = 2*Height + 7.8*Age + 1.7*Weight – 192.9

A PEFR nomogram for males and females was created from the equation (a sample for males is represented in table 1).

Conclusions Predicted PEFR values were represented in a nomogram as a reference to the adolescent population in the state and may be used to evaluate PEFR in health facilities in the region.