An Inside Look at the Latest ATS/ERS Guidelines

Intro

Dawn Patterson, ERT Director of Respiratory Solutions, is joined by Kevin McCarthy, ERT Clinical Overread Specialist and member of the ATS/ERS 2019 Spirometry Update Task Force. They’ll explore the implications of the October 2019 ATS/ERS update to their pulmonary function testing guidance. ERT was the only data and technology vendor involved in the update.

What are the ATS/ERS guidelines?

These guidelines represent what can be considered as worldwide standards that ensure the quality of pulmonary function measurements. This type of measurement is somewhat unique in that it requires a high degree of patient understanding and cooperation.

When were the ATS/ERS guidelines last updated?

Spirometry standards were first published 40 years ago, and updated approximately every 10-15 years since. The last time they were updated prior to 2019 was 2005.

How did you get involved in the task force that was responsible for updating the guidelines?

I was approached by the ATS/ERS to participate on a committee to develop an accreditation for pulmonary function laboratories. While working on that project, I was asked if I’d be interested in participating on the update task force.

How is this guidance used in clinical research?

Typically, ATS/ERS guidelines are incorporated in testing protocol for clinical trials. This is important in guaranteeing comparability of tests obtained from multiple global testing sites. In the 2019 guidelines, it’s specified that these standards represent the minimum criteria that must be met for clinical spirometry only - not necessarily for research or occupational surveillance. In clinical trials, sometimes the bar should be set higher.

What are the most important changes in the new spirometry guidelines?

One of the most important changes involves the recognition that the forced exhalation could be performed perfectly but still give erroneously low results. The new standards emphasize the need to look at the subject for feedback, and gives detailed guidance to site operators on how to vigorously coach patients to full inflation.

The new standards also stipulate that the procedure does not end with the forced exhalation. At the end of the forced exhalation, the subject is again vigorously coached to full inflation, allowing for a comparison to the FVC that allows operators to verify the forced exhalation started from full inflation.

In recognition that pediatric patients and patients with interstitial lung disease had difficulty in meeting end-of-test acceptability criteria, these acceptability criteria were redefined in a manner that accommodates the lung physiology of these groups.

Finally, the updated standards provide a new letter grading standard for acceptability based on the two main forced spirometry parameters. In the old standards, if an effort failed to meet the start of test criteria, the effort was considered to be unusable for reporting. In the new standards, an effort that is unusable for FEV1 may be acceptable for FVC and vice versa.

Are there any minor changes to the guidance that people need to look out for?

This document makes recommendations to the manufacturers about features that they should provide for the users of their testing equipment. One of the recommendations made was that the manufacturers provide standard lists of operator comments. These lists allow the operator to quickly select a comment from a list (in addition to adding free text) to provide insight and context about quality issues for study teams or physicians.

How will this new guidance impact sites and patients in respiratory clinical trials?

This new update of the spirometry standards will likely reduce the number of times a patient will have to perform the forced expiratory maneuver to achieve acceptability, improve data repeatability and improve data quality by verifying all efforts start from full inflation. This should result in a big win for sponsors, especially in studies involving pediatric patients and patients with interstitial lung disease.

Final thoughts:

There was an increased recognition of the importance of the operator administering the test in getting quality results. Operator training and the attainment and maintenance of competency must be integrated in any spirometry testing service.