Quantitative start of test criteria for spirometry in preschool children

2007 ATS/ERS statement in pulmonary function testing in preschool children recommends that any curve with the back-extrapolated volume (BEV) greater than 80ml or 12.5% of forced vital capacity (FVC) should be re-inspected. Our goal was to determine the accuracy of this criterion in large number of young children. Spirometry was measured in 1515 children (healthy and asthmatic) between 3.05 and 5.92 years of age according ATS standards, with an average success rate of 84.2%. See tables 1 and 2 for main results. 14% of children obtained a BEV greater than 80ml and re-inspection of their curves showed 48% were acceptable. 2.4% of children had a BEV>95ml, with acceptable curves only in 3%. Children with a BEV>95ml obtained a significantly lower FEV_0.75 (0.60L versus 0.97L, p<0.01). More than 99% of children obtained BEV/FVC<12.5%, with a statistically significant difference between children 3.1-3.9 versus 4.0-5.9 years old, then it would be possible to decrease this limit especially in children of 4 and 5 years of age. In conclusion, we suggest spirometric acceptability criteria be changed to a BEV of 95 ml and to reduce BEV/FVC limit in children 4.0-5.9 years old. Table 1. <table-wrap><object-id>erj;64/suppl_68/PA1461/TB1</object-id><object-id>T1</object-id><object-id>TB1</object-id><table><colgroup><col></col><col></col><col></col><col></col><col></col></colgroup><tbody><tr><td></td><td>All children</td><td>3.1-3.9 years</td><td>4.0-4.9 years</td><td>5.0-5.9 years</td></tr><tr><td>Mean BEV in ml (SD)</td><td>61 (15)</td><td>58 (16)</td><td>61 (11)</td><td>63 (18)</td></tr><tr><td>Mean BEV/FVC in % (SD)</td><td>5.4 (1.4)</td><td>6.5 (2.0)</td><td>5.3 (0.9)</td><td>4.9 (1.4)</td></tr></tbody></table></table-wrap> Table 2. <table-wrap><object-id>erj;64/suppl_68/PA1461/TB2</object-id><object-id>T2</object-id><object-id>TB2</object-id><table><colgroup><col></col><col></col><col></col><col></col><col></col></colgroup><tbody><tr><td>BEV limit in ml</td><td>Sensitivity</td><td>Specificity</td><td>PPV</td><td>NPV</td></tr><tr><td>80</td><td>96.1%</td><td>57.2%</td><td>35.4%</td><td>98.3%</td></tr><tr><td>95</td><td>95.1%</td><td>96.1%</td><td>83.0%</td><td>99.0%</td></tr></tbody></table></table-wrap>