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New GOLD guidelines recommend using pre-bronchodilator spirometry to rule out COPD and post-bronchodilator measurements to confirm a COPD diagnosis.

For decades, the Global Initiative for Chronic Obstructive Lung Disease (GOLD) report has advised COPD assessment in patients with chronic respiratory symptoms and/or exposure to cigarette smoking and other risk factors. To confirm COPD, forced spirometry showing airflow obstruction after bronchodilation is required, using a threshold of post-bronchodilator (BD) forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) ratio of less than 0.7.

“The concept that airflow obstruction in COPD is persistent and cannot be fully reversed provided the rationale for this recommendation, with post-BD FEV1/FVC less than 0.7 ensuring that the diagnosis of COPD was confined to people with persistent airflow obstruction despite BD treatment,” wrote corresponding author Dave Singh, MD, and colleagues in a report published in the European Respiratory Journal.

After reevaluating evidence for using pre- or post-BD spirometry to diagnose COPD, the GOLD science committee now recommends using pre-BD spirometry to rule out COPD and post-BD measurements to confirm a COPD diagnosis.

“This will reduce clinical workload,” Dr Singh and coauthors advised.

Pre- and post-BD spirometry have been shown to provide consistent results in most patients, although the use of post-BD values lowers the prevalence of COPD by more than one-third, the report’s authors explained. Issues may occur in “volume” responders and “flow” responders.

“Volume responders have reduced FVC due to gas trapping causing FEV1/FVC greater than or equal to 0.7 pre-BD,” the authors wrote, “but a volume response occurs post-BD with a greater improvement in FVC relative to FEV1, decreasing the ratio to less than 0.7.”

In flow responders, flow responses increase the FEV1/FVC ratio from less than 0.7 pre-BD to greater than or equal to 0.7 post-BD. Nevertheless, patients with a flow response have an increased chance of developing COPD and should be monitored over time.

Per the GOLD 2025 report, pre-BD spirometry is useful as an initial test to identify airflow obstruction. If results do not indicate obstruction, most patients will not need post-BD spirometry. Instances where the clinical suspicion of COPD is high are an exception. Additionally, lower pre-BD FEV1 measurements (<80% predicted) could signal a volume responder.

“Post-BD results close to the threshold should be repeated to ensure a correct diagnosis is made,” the authors wrote. “Post-BD measurements ensure that volume responders are not overlooked and limit COPD overdiagnosis.”