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

Abstract

BACKGROUND AND AIMS: Spirometry 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. METHODS: Spirometry was performed in 2078 healthy 13-14 year old Sri Lankan children (1023 boys (49.2%) and 1055 (50.8%) girls) according to American Thoracic Society guidelines. Forced Vital Capacity (FVC), Forced Expiratory Volume in the first second (FEV1), 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 FEV1, PEF and FEF25-75% in females. The prediction equations in males for FVC: 0.047height + 0.0007age- 4.66; for FEV1: 0.041height + 0.016age - 4.22; for PEFR: 0.074height + 0.123age - 7.59 and FEF25- 75%: 0.042height + 0.066 age - 4.36. The equations in females for FVC: 0.028height + 0.031age - 2.36; for FEV1: 0.027height + 0.047age - 2.57; for PEFR: 0.038height + 0.159age - 2.93 and FEF25-75%: 0.02height + 0.136age - 3.18. CONCLUSIONS: Height and age influence ventilatory parameters and could be used to assess lung functions in Sri Lankan children.