Chronic obstructive pulmonary disease (COPD) and congestive heart failure (CHF) are two of the most common medical reasons for hospitalization among middle-aged and older patients. Both 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 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.