Spirometric reference values in school children from Dalmatia

Data on spirometric reference values in children are based on small, selected populations. We performed spirometric testing (forced vital capacity (FVC); forced expiratory volume in one second (FEV1); forced mid-expiratory flow rate (FEF25-75%)) in 2,500 healthy nonsmoking school children (1,250 boys and 1,250 girls) in the region of Dalmatia, Croatia. Significantly higher FVC and FEV1 values were noted in boys. Standing and sitting heights correlated significantly with FVC and FEV1 in boys and girls. Regression equations were derived, utilizing the multiple linear regression analysis, for FVC, FEV1 and FEF25-75% related to five (sex, age, weight, standing and sitting heights) or three (sex, age and standing height) variables. The reference spirometric values in the Dalmatian school boys were in close agreement with Knudson et al., while the values in girls were closest to those of Knudson et al. and Cotes et al. It is suggested that for calculation of ventilatory reference values in boys and girls the age and the standing height should be used.