Comparison of spirometric results obtained in sitting and standing position in children participating in epidemiological study

Abstract

It9s recommended that spirometric testing in children be completed while sitting, our experience is that children feel more comfortable standing during spirometry. Aim: We sought to compare spirometric results obtained from the sitting (SI) and standing (ST) positions. Method: Two testing sessions were performed in random order (SI vs ST position: testing 30-45 min. apart) in 118 children aged 7-13 y-rs, attending randomly selected, primary school in town of Katowice (response rate: 92%). Results: Tests of acceptable quality were found in 77.9% of ST and 77.1% of SI position - 29 girls and 49 boys (mean age=9.0±1.6 y-rs). The frequency of chronic cough was 33.7%, of chest wheeze was 11.6%, and of attacks of dyspnea was 9.0%. Higher values of spirometric variables on ST, compared to SI position, were for FVC (2.12±0.41 l vs 2.11±0.39 l) and FEV 1 (1.78±0.36 l vs 1.77±0.35) but the differences were not statistically significant. Mean relative between-position differences [RBPD] were for FVC: 5.5±4.5%, FEV 1 : 5.8±6.6%, PEF: 12.4±9.5%, and FEF 2575 : 15.9±16.8%. RBPD ≤ 5% was found in: FVC: 56.4 %, FEV 1 : 69.2 %, PEF: 21.7%, and FEF 2575 : 24.3%. Patterns for FEF 25 , FEF 50 , and FEF 75 were similar. RBPD were related to age in the case of FEV 1 (p=0.005), FEF 25 (p=0.02), FEF 2575 (p=0.01) where older children had smaller RBPD. FVC RBPD was lower (p=0.01) in subjects with current wheeze while PEF RBPD was lower (p=0.02) in children with asthma. No cases of adverse events. Conclusion: In epidemiological studies of children, the position of spirometric testing does not seem to affect the result of lung function assessment or the safety level of the measuring procedure.