New ATS Guidance Proposes Standardized Language for Pulmonary Function Test Interpretation
November 3, 2025
A recent guidance document from the American Thoracic Society (ATS), published in Annals of the American Thoracic Society, proposes standardized language for interpreting pulmonary function test (PFT) results. The document, developed by the ATS Pulmonary Function Test Committee, addresses inconsistencies in how clinicians may describe and report PFT findings. The working group included pulmonologists and physiologists from institutions across North America, including Daniel J. Weiner, MD, FAAP, FCCP, ATSF, the Antonio J. and Janet Palumbo Professor of Pediatrics at the University of Pittsburgh School of Medicine. Dr. Weiner is director of the Pulmonary Function and Pulmonary Exercise Laboratories and codirector of the Antonio J. and Janet Palumbo Cystic Fibrosis Center in the Division of Pediatric Pulmonary Medicine at UPMC Children’s Hospital of Pittsburgh.
The guidance builds upon prior standards jointly issued by the European Respiratory Society and the American Thoracic Society (ERS–ATS), which established the technical and algorithmic foundations of PFT interpretation. Its goal is to bridge the gap between quantitative data and the narrative summaries that appear in clinical reports. To facilitate this, the group developed standardized language for common patterns of obstruction, restriction, and gas-transfer impairment, as well as guidance for reporting test quality and borderline findings. The recommendations are designed to improve interpretive clarity, reduce variation across laboratories, and promote consistency in communication between specialists, referring clinicians, and patients.
“Inconsistencies do exist in how physicians interpret and describe pulmonary function testing, even with the existence of ATS guidelines,” Dr. Weiner says. “Two developments in recent years related to the adoption of race-neutral equations from the Global Lung Function Initiative and the shift toward standard deviation scores instead of percent-predicted thresholds have reshaped interpretation. Our laboratory has used standard deviation scores for more than a decade and transitioned to race-neutral equations in 2023, but many centers are still in the process of adapting to these updates.”
The standardized language outlined in the paper mirrors how PFT reports are structured, with parameter-specific findings followed by an integrated physiologic impression.
“PFT results alone do not provide a diagnosis,” Dr. Weiner says. “They support clinical reasoning when interpreted in the broader context of symptoms and history. Because many patients, particularly those with chronic lung disease review their results, clear and consistent terminology is essential for everyone’s understanding.”
The guidance document from the ATS also emphasizes cautious interpretation of borderline findings in light of how new reference equations can alter prior thresholds.
“Borderline results require careful consideration,” Dr. Weiner says. “A value that appears slightly abnormal may fall within normal limits using updated equations, which can have implications for clinical trials, occupational testing, and other determinations based on fixed cutoffs.”
From a pediatric standpoint, the proposed framework applies broadly across age groups but requires attention to technical factors and patient effort.
“Obtaining reproducible PFT results from younger children can be challenging,” Dr. Weiner says. “Our reports document effort and repeatability to help distinguish true physiologic limitation from suboptimal test performance.”
The new guidance from ATS serves as a supplement to existing ERS–ATS interpretation standards and gives clinicians a reference for constructing concise, standardized PFT interpretations that integrate technical accuracy with clinical usability.
Learn more about Dr. Weiner and the Division of Pediatric Pulmonary Medicine at UPMC Children’s Hospital of Pittsburgh.
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