Current criteria for judging acceptability and repeatability
| Evaluation item | Detailed criteria |
|---|---|
| Number of measurements | Repeat for a minimum of three measurements |
| Acceptability | |
| Good start | Extrapolated volume <5% of FVC or 0.15 L, whichever is greater |
| Free from artifacts |
Cough during the first second of exhalation Glottis closure that influences the measurement Early termination or cut-off Effort that is not maximal throughout Leak Obstructed mouthpiece |
| Satisfactory exhalation | Duration of ≥6 s or a plateau in the volume–time curve |
| Repeatability |
After three acceptable spirograms have been obtained, The two largest values of FVC must be within 0.150 L of each otherthe two largest values of FEV1 must be within 0.150 L of each other |
| Criteria for data that cannot be judged to be acceptable or repeatable |
Results without Volume-Time or Flow-Volume curves Data inconsistent with the results reported to the Ministry of Employment and Labor Clear result of equipment malfunction Results of abnormal increase or decrease compared to previous results Results judged not to be the test result of the examinee |
Adopted from Miller et al (Eur Respir J. 2005;26:319-338) [4].
Abbreviations: FVC, forced vital capacity; FEV1, forced expiratory volume in one second.
