Bronchodilator Response (ATS/ERS 2005 & 2021)

• The bronchodilator response is available when both a pre- and post-bronchodilator spirometry session have been performed with valid results.

• It appears above the bronchodilator graph and is also included in the automatically generated summary text.

• Both ATS/ERS 2005 and 2021 standards are supported.

  • Default depends on region:

    • Norway and US → ATS/ERS 2021

    • All other regions → ATS/ERS 2005

  • Clinic admins can change the default setting in Clinic settings.

• Not available for tests made prior to [the release date].

There are two calculation methods, depending on which ATS/ERS guideline is applied.

ATS/ERS 2005 Standard

• A bronchodilator response is Significant if there is an increase of ≥12% and ≥200 mL in FEV₁ or FVC compared with the baseline (best pre-test value).

• All other results are Not significant.

ATS/ERS 2021 Technical Standard

• A bronchodilator response is Significant if the difference between pre- and post-test is >10% of the predicted value in FEV₁ or FVC.

  • Example: If the predicted FVC is 3.5 L, 10% corresponds to 0.35 L.

  • A difference greater than 0.35 L is considered Significant.

• All other results are Not significant.

The bronchodilator response may show one of the following outcomes:

• Significant

• Not significant

If the result cannot be determined, the display will show:

• “Select trials from both sessions to calculate,”

• “Not available – Incomplete test,” or

• “Not available for tests made prior to [release date].”

• By default calculations use the best accepted trial from the pre- and post-sessions.

• The calculation updates if selected trials are changed in either the pre- or post-bronchodilator session.

• The significance label always reflects the standard configured in your clinic’s settings.