RT Journal Article SR Electronic T1 LUNOKID: can numerical American Thoracic Society/European Respiratory Society quality criteria replace visual inspection of spirometry? JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 1347 OP 1356 DO 10.1183/09031936.00058813 VO 43 IS 5 A1 Christine Müller-Brandes A1 Ursula Krämer A1 Monika Gappa A1 Gabriele Seitner-Sorge A1 Anke Hüls A1 Andrea von Berg A1 Barbara Hoffmann A1 Antje Schuster A1 Sabina Illi A1 Matthias Wisbauer A1 Dietrich Berdel YR 2014 UL http://erj.ersjournals.com/content/43/5/1347.abstract AB The gold standard for assessing quality of forced expiratory manoeuvres is visual inspection by an expert. American Thoracic Society/European Respiratory Society numerical quality criteria (NQC) include back-extrapolated volume (BEV), repeatability and forced expiratory time (FET). Equipment currently available provides feedback tempting the investigator to use NQC as pass–fail criterion. To investigate whether using NQC instead of visual acceptability is a valid option, we analysed data from a multicentre national reference study in Germany of children aged 4–18 years. Spirometry was performed under field conditions. Receiver operating characteristic analysis was used to assess performance of BEV, repeatability, FET and a combination thereof in relation to visual acceptability. We included data from 3133 healthy Caucasians in the analyses; 72% delivered at least two visually acceptable manoeuvres. Of these, 59% would have been rejected based on combined NQC, mainly because the FET criterion was not feasible. Specificity of the NQC was generally low (BEV 10%, repeatability 30% and FET 50%). Receiver operating characteristic analysis showed that a combination of the three measures could reach at best a sensitivity of 90% and specificity of 56%. We conclude that visual control is mandatory and NQC may help obtain the best possible results, but a fixed cut-off for FET should be abandoned. Visual control of spirometry is mandatory: quality criteria may help to get best results, but we should abandon FET http://ow.ly/uje5B