New Study Shows Big Discrepancy in Use of Standard Tests to Diagnose Lung vs Cardiac Disease in Hospitalized Patients

For Immediate Release

Chronic obstructive pulmonary disease (COPD) and congestive heart failure (CHF) each affect millions of Americans, and these conditions are two of the most common medical reasons for hospitalization among middle-aged and older patients.  Both COPD and CHF have accepted standards for diagnosis and management, supported by large bodies of scientific evidence and international practice guidelines.  Yet a new study from Boston’s Caritas St Elizabeth’s Medical Center, published in the October issue of Respiratory Care, shows that the use of the primary confirmatory tests—recommended both for diagnosis and assessment of severity—differs substantially in the two diseases.     

According to widely-accepted guidelines such as those of the Global Initiative for Obstructive Lung Disease (www.goldcopd.com), diagnosing COPD and choosing appropriate therapy based on disease severity relies on spirometry, a simple test in which lung capacity and how fast air can be expelled from the lungs are measured noninvasively in a doctor’s office or laboratory. 

The new study, by Mahendra Demarla and colleagues, shows that only about one-third of patients admitted to the hospital with the diagnosis of “COPD” during a recent 6-month period had had spirometry performed either in the hospital or during the preceding 8 years.  This means that the majority of patients who required hospitalization for this common and life-threatening condition had not undergone the specific test required to confirm that this diagnosis was correct. 

Further, the investigators found that, of the patients who had undergone spirometry, in 10% of instances the findings were normal, indicating that the diagnosis of COPD was incorrect, and in another 19% it revealed a different functional pattern suggesting the presence of some other lung disease.

In contrast to the low frequency in which the appropriate test had been performed to confirm the physician’s impression that the patient had COPD, 78% of patients admitted for CHF had had an echocardiogram, the standard test for confirming this diagnosis. 

COPD is estimated to affect 10 to 20 million Americans, and is the fourth leading cause of death, claiming approximately 120,000 lives each year.  The new study by Demarla and associates suggests a major gap in the quality of diagnosis—and potentially also in the appropriateness of management—among patients hospitalized with the diagnosis of COPD compared to that of CHF.  

Like echocardiography, spirometry is readily available in every hospital.  Generally performed by a respiratory therapist, spirometry takes less than 5 minutes to perform, causes minimal patient discomfort, and is inexpensive.  The new Respiratory Care study suggests that underuse of this test may affect the accuracy of diagnosis, and the effectiveness of treatment, in many if not most patients who require hospital treatment for COPD.    

For further information about spirometry or the diagnosis and management of COPD, or to contact the authors of this study, contact Sherry Milligan at the American Association for Respiratory Care.

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Contact: Sherry Milligan
milligan@aarc.org
American Association For Respiratory Care
9425 N MacArthur Blvd, Suite 100, Irving , TX 75063
972-406-4657, 972-243-2272