Peak Expiratory Flow Rate in Healthy Children from Tehran

Background: Measuring peak expiratory flow rate has been suggested as an important tool in asthma management by all international guidelines. Objective: Studies on various populations have shown considerable variations in normal values of peak expiratory flow rate. Since reference standards for Iranian children are not available, the present study was performed to establish these standards. Methods: This study was conducted on 1535 normal schoolchildren (767 female, 768 male), aged 6-14 in Tehran. A mini Wright peak flow meter was used to measure peak expiratory flow rates. The highest of the three readings was taken as the correct value. Regression analysis was used to calculate the predicted normal values of peak expiratory flow rate and also to assess its relationship to age, weight, height, and surface area. Results: Peak expiratory flow rate values increased with age and were in strong correlation with the studied anthropometric measurements. Except for the 145-159 cm interval, the male children showed significantly higher values (P<0.01) of peak expiratory flow rate in comparison to female children. Conclusion: The peak expiratory flow rates for Iranian schoolchildren were similar to some of those reported from other countries and could be used by Iranian physicians for proper management of paients.