RESUMEN
Spirometry was performed in 186 healthy school children, 6-13 years of age, selected from urban population of Rohtak city (India), to derive the regression equation for prediction of normal value of ventilatory lung function in this age group. Values of lung functions in the present study are well comparable to other North Indian studies and Western reports, but higher than the South Indian children. Lung functions have shown better linear correlation with age and height as compared to weight. Comparison of ventilatory function tests in boys and girls showed statistically higher FVC, FEV1, PEFR, FEF25% and MVV in boys, while FEF50% FEF75% and FEF75-85% were statistically higher in girls in different age groups. No specific pattern of variation in lung function tests was observed with sex. Regression equations for different ventilatory functions have been derived for either sex with the best possible combination of physical parameters.