Spirometry reference norms for 13-14 year old Sri Lankan children

Abstract

INTRODUCTION AND OBJECTIVES: Reference norms have only been reported for Peak Expiratory Flow Rate (PEFR) in Sri Lankan children. The aim of this study was to construct prediction equations for spirometry in Sri Lankan children aged 13-14 years. METHOD: Spirometry was performed in 2078 Sri Lankan healthy children (1023 boys (49.2%) and 1055 (50.8%) girls) of 13-14 years of age according to American Thoracic Society guidelines. Forced Vital Capacity (FVC), Forced Expiratory Volume in the first second (FEVi), PEFR and Forced Mid-Expiratory Flow Rates (FEF25-75%) were measured. Correlation coefficients were established between each parameter and standing height, weight, and age. The functions were regressed over all possible combinations of variables separately for boys and girls. RESULTS: There were significant correlations between spirometry parameters and height and weight in both genders. There were significant correlations between age and PEFR, FEF25 and FEF50 in males and age and FEVi, PEF and FEF25-75% in females. The prediction equations in males for FVC: 0.047 height + 0.0007 age - 4.66; for FEVi: 0.041 height + 0.016 age - 4.22; for PEFR: 0.074 height + 0.123 age - 7.59 and FEF25-75%: 0.042 height -i-0.066 age-4.36. The equations in females for FVC: 0.028 height + 0.031 age - 2.36; for FEVi: 0.027 height + 0.047 age - 2.57; for PEFR: 0.038 height + 0.159 age - 2.93 and FEF25-75%: 0.029 height + 0.136 age-3.18. CONCLUSION: Height, weight and age influence ventilatory parameters and could be used to formulate prediction equations for spirometry in Sri Lankan children.