What are the acceptability, usability, and repeatability criteria for FEV1 and FVC in pulmonary function testing?

Updated: May 14, 2020
  • Author: Kevin McCarthy, RPFT; Chief Editor: Nader Kamangar, MD, FACP, FCCP, FCCM  more...
  • Print
Answer

Answer

 

Table 1. Summary of Acceptability, Usability, and Repeatability Criteria for FEV1 and FVC (Open Table in a new window)

Acceptability and Usability

Required for Acceptability

Required for Usability

Criterion

FEV 1

FVC

FEV 1

FVC

Must have back extrapolated volume ≤5% of FVC or 0.100 L, whichever is greater

+

+

+

+

Must have no evidence of a faulty zero-flow setting

+

+

+

+

Must have no cough in the first second of expirationa

+

-

+

-

Must have no glottis closure in the first second of expirationa

+

+

+

+

Must have no glottis closure after 1 s of expiration

-

+

-

-

Must achieve one of these three end of forced expiration indicators:

  • Expiratory plateau (≤0.025 L in the last 1 s of expiration)
  • Expiratory time ≥15 s
  • FVC is within the repeatability tolerance of, or is greater than, the largest prior observed FVC b

-

+

-

-

Must have no evidence of obstructed mouthpiece or spirometer

+

+

-

-

Must have no evidence of a leak

+

+

-

-

If the maximal inspiration following end of forced expiration is >FVC, then FIVC – FVC must be ≤ 0.100 L or 5% of FVC, whichever is greaterc

+

+

-

-

Repeatability Criteria  (applied to acceptable FVC and FEV1 values)  

Age >6 y:  Difference between two largest FVC values must be ≤0.150 L, and the difference between two largest FEV1 values must be ≤0.150 L

Age ≤6 y:  Difference between two largest FVC values must be ≤0.100 L or 10% of the highest value, whichever is greater, and the difference between two largest FEV1 values must be ≤0.100 L or 10% of the highest value, whichever is greater

aFor children ≤6 y, must have at least 0.75 s of expiration without glottis closure or cough for acceptable or useable measurement of FEV0.75.

bOccurs when the patient cannot expire long enough to achieve a plateau (eg, children with high elastic recoil or patients with restrictive lung disease) or the patient inspires or comes off the mouthpiece before a plateau. For within-maneuver acceptability, the FVC must be larger than or within the repeatability tolerance of the largest FVC observed before this maneuver within the current prebronchodilator or the current postbronchodilator testing set.

cAlthough the performance of a maximal forced inspiration is strongly recommended, its absence does not preclude a maneuver from being judged acceptable, unless extrathoracic obstruction is specifically being investigated.

Table 2. Quality Categories for FVC or FEV1 in Adults and Children (Open Table in a new window)

Grade

Criteria for Adults, Older Children, and Children Aged 2-6 Years

A

> 3 acceptable efforts with repeatability within 0.150 L

     for age 2-6 y, 0.100 L, or 10% of highest value, whichever is greater

B

2 acceptable efforts with repeatability within 0.150 L

     for age 2-6 y, 0.100 L, or 10% of highest value, whichever is greater

C

> 2 acceptable efforts with repeatability within 0.200 L

     for age 2-6 y, 0.150 L, or 10% of highest value, whichever is greater

D

> 2 acceptable efforts with repeatability within 0.250 L

     for age 2-6 y, 0.200 L, or 10% of highest value, whichever is greater

E

One acceptable  effort

F

No acceptable efforts

Note that FEV1 and FVC each are graded separately.


Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!