Acceptability & Usability Criteria

What are Acceptability & Usability Criteria?

For any spirometry results to be acceptable and usable, the measurements should meet some criteria. These criteria are determined by the Standardization of Spirometry 2019 Update by American Thoracic Society and European Respiratory Society.

The criteria, in essence, are used to see if a maximal effort was achieved and acceptable FEV1 and/or FVC measurements were obtained. But in some cases, the maneuvers that don't meet the criteria may be the best the subject is capable of, in which case even though FEV1 and FVC measurements aren't technically acceptable, they may still be usable in the clinical sense.

Acceptability & usability criteria for FEV1

For a FEV1 value to be acceptable, the following criteria must be met: 

  • Must have a BEV equal to or less than 5% of FVC, or 0.100 L, whichever is greater
  • Must have no evidence of a faulty zero-flow setting
  • Must have no cough or glottic closure in the first second of expiration
  • Must have no evidence of obstructed mouthpiece or spirometer
  • Must have no evidence of a leak
  • If the maximal inspiration after EOFE is greater than FVC, then FIVC - FVC must be equal to or less than 0.100 L or 5% of FVC, whichever is greater

For a FEV1 value to be usable, the following criteria must be met:

  • Must have a BEV equal to or less than 5% of FVC, or 0.100 L, whichever is greater
  • Must have no evidence of a faulty zero-flow setting
  • Must have no cough or glottic closure in the first second of expiration

Acceptability & usability criteria for FVC

For a FVC value to be acceptable, the following criteria must be met: 

  • Must have a BEV equal to or less than 5% of FVC, or 0.100 L, whichever is greater
  • Must have no evidence of a faulty zero-flow setting
  • Must have no glottic closure in the first second of expiration
  • Must have no glottic closure after 1 s of expiration
  • Must have no evidence of obstructed mouthpiece or spirometer
  • Must have no evidence of a leak
  • If the maximal inspiration after EOFE is greater than FVC, then FIVC - FVC must be equal to or less than 0.100 L or 5% of FVC, whichever is greateD22 - What are Acceptability & Usability Criteria_-1

Also, the maneuver should meet one of the following three EOFE (end of forced exhalation) criteria for it to be acceptable, but this is not a requirement for usability:

  • Expiratory plateau (<0.025 L in the last 1 second of expiration)
  • Expiratory time is more than 15 seconds
  • FVC is within the repeatability tolerance of or is greater than
    the largest prior observed FVC

Maneuvers that do not meet any of the EOFE acceptability criteria will not provide acceptable FVC measures. However, an acceptable FEV1 measurement may be obtained from a maneuver with early termination after 1 second.

For a FVC value to be usable, the following criteria must be met:

  • Must have a BEV equal to or less than 5% of FVC, or 0.100 L, whichever is greater
  • Must have no evidence of a faulty zero-flow setting
  • Must have no glottic closure in the first second of expiration

A cough during the first second of the maneuver can affect the measured FEV1 value, and the FEV1 from such a maneuver is neither acceptable nor usable. However, the FVC may be acceptable.

If there is a cough after the first second of the maneuver, FEV1 value would be usable, but FVC is not usable.

Glottic closure or early termination, such as inspiration or coming off the
mouthpiece, renders FVC unacceptable and, if it occurs in the first 1 second, renders FEV1 unacceptable and unusable. A similar termination in the first 0.75 seconds renders FEV0.75 unacceptable and unusable.

Sources

  1. "Standardization of Spirometry 2019 Update". An Official American Thoracic Society and European Respiratory Society Technical Statement, 2019.

Don't forget to share this post!