Conflicting Standards for COPD Could Hurt Patients

Laird Harrison

October 24, 2011

October 24, 2011 (Honolulu, Hawaii) — The competing standards for evaluating chronic obstructive pulmonary disease (COPD) could lead to errors in both diagnosis and treatment, warned researchers here at CHEST 2011: American College of Chest Physicians Annual Meeting.

There are important differences in the way patients are classified by the Global Initiative for Chronic Obstructive Lung Disease (GOLD) and the American Thoracic Society/European Respiratory Society (ATS/ERS), said Ameer Rasheed, MD, from The Brooklyn Hospital Center, in New York, in presenting the results of a study on the issue.

"There is a need for a joint GOLD–ATS/ERS consensus statement to resolve these conflicts," he asserted.

To see how different the standards are, Dr. Rasheed and his colleagues retrospectively reviewed the records of 217 patients with a COPD diagnosis and applied the 2 different standards to them.

They found that there was a discordance in diagnosis in 24 (11%) of the patients. Twenty patients, with a median age of 64 years, met the GOLD criteria for COPD but not the ATS/ERS criteria, whereas 4, with a median age of 41 years, met the ATS/ERS criteria but not the GOLD criteria.

That led the researchers to conclude that older patients might be overdiagnosed and younger patients underdiagnosed.

An additional 39 patients were categorized as mild by ATS/ERS but moderate by GOLD.

How are the standards different? Under GOLD, a patient should be diagnosed with COPD if the patient's forced vital capacity divided by forced expiratory volume in 1 second (FEV1/FVC%) is below 70. Under ATS/ERS, COPD is diagnosed when FEV1/FVC% is less than the lower limit of normal established by the National Health and Nutrition Examination Survey (NHANES).

A patient is classified as "mild" if the FEV1/FVC is over 80% under GOLD, but 70% under ATS/ERS. A patient is "severe" if that measurement is 50% to 80% under GOLD, but 50% to 70% under ATS/ERS.

"Severe" is 30% to 49% under GOLD but 35% to 49% under ATS. "Very severe" is less than 30% under GOLD and less than 35% under ATS/ERS.

On the basis of these discrepancies, clinicians might treat their patients differently, said Dr. Rasheed, such as when making a choice between long-acting beta agonists and short-acting beta agonists.

This could have implications for the cost of treatment and the health of the patient, he said, estimating that long-acting beta agonists cost $100 per month, whereas the short-acting variety cost half that.

Comoderator Brian W. Carlin, assistant professor at Drexel University in Pittsburgh, Pennsylvania, told Medscape Medical News that the discrepancies are particularly important for mild to moderate patients.

Changes are already underway, he said; he expects GOLD to introduce revised standards in a few months.

But he acknowledged that it might be too early to forge a consensus on guidelines. "Lung function measurement may not be the best way to do classification," he said. "I think more research has to be done to look at the natural history of the patients."

Dr. Rasheed has disclosed no relevant financial relationships. Dr. Carlin reports receiving speaking fees from GlaxoSmithKline, Boehringer-Ingelheim, and Forest Pharmaceuticals.

CHEST 2011: American College of Chest Physicians Annual Meeting: Abstract 888A. Presented October 23, 2011.


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