Reference values for peak nasal inspiratory flow in children and adolescents in Brazil

Statement of the problem: Allergic rhinitis is a global public health issue. Peak nasal inspiratory flow (PNIF) can help in the assessment of patients with allergic rhinitis. However reference values in the literature for PNIF in school children and adolescents are limited. The aim of this study was to identify reference values of PNIF among children and adolescents. Methods: We conducted a cross-sectional study to identify reference values of PNIF among healthy school children and adolescents aged from eight to fifteen years old, selected from 14 randomly selected public schools. Participants performed measurements of PNIF using the In-check-inspiratory flow meter (Clement Clarke, Harlow, England). PNIF values were correlated to gender, age, height, weight and body mass index. Results: A total of 526 subjects participated in the study The final linear regression model for PNIF allowed obtaining the following equation for subjects aged from eight to 15 years old: PNIF (l/m) = height (centimeters) x 0.7 + 11.2, for boys and PNIF (l/m) = height (centimeters) x 0.7, for girls. Conclusion: the equations of the final regression model resulted in a simple formula to obtain reference values of PNIF for subjects aged from 8 to 15 years old.