Is it COPD or Another Diagnosis?
Leading organizations, including the American Thoracic Society, highlight that while mortality rates of the leading causes of death in the U.S. heart disease and cancer have decreased, the mortality rate of COPD has actually increased over the past five years.
Some say that COPD is underdiagnosed and often not recognized until it is in its irreversible stages. The paradox is that many of pulmonologists, like me, feel quite the opposite. We feel that COPD is over-diagnosed or misdiagnosed in certain individuals. These patients present with a history of smoking, and are either short of breath or coughing chronically. Being diagnosed with COPD (incorrectly) obviously has profound implications in terms of treatment goals. More importantly, it has serious implications regarding the risks of complications, when the wrong treatment is instituted.
What is COPD?
The acronym stands for Chronic Obstructive Pulmonary Disease. The components of the disease include emphysema, a condition caused by the imbalance of enzymes in the lung that regulate elasticity (which can lead to stretching of the lungs or hyperinflation). This results in the person having to double their energy use in order to breathe since exhaling should be a passive effort, allowed the natural elasticity of the lung, which is lost in emphysema.
The second component is a secretion clearance issue. The normal amounts of secretions made in the lungs are not cleared effectively, because of a deficiency in the hairy structures of the cells called cilia. The result is chronic cough, which is called chronic bronchitis. Emphysema, coupled with chronic bronchitis, is known formally as COPD.
Shortness of breath and chronic cough are really common findings in a number of diseases. So these symptoms alone should not warrant an immediate diagnosis of COPD. It is true that 90 percent of COPD patients are long-term smokers, but it may shock you to know that only 20 percent of smokers go on to develop COPD. There is a unique feature to this selected group of individuals - an accelerated destruction process in the lungs. That means the diagnosis is not just based on symptoms, but based on identifying unique anatomical features coupled with inflammatory and destructive processes in the lungs. That also means that a large group of patients (smokers and non-smokers) is currently labeled with the diagnosis of COPD, but actually have an entirely different diagnosis.
What is the danger? Well, if their symptoms are in fact due to heart disease, rather than COPD, they may be receiving drug therapies that can cause further harm by increasing the risk of irregular heart rhythms and worsening heart symptoms in a patient with ongoing heart disease. In fact, the most popular medication used to treat COPD has a black box warning regarding possible negative side effects in the form of cardiac (heart) events.
Another dangerous outcome from an incorrect diagnosis of COPD is that inhaled steroids a first line of therapy in this condition has been associated with increased rates of pneumonia. This would be a serious potential problem in patients who have impaired immunity and are vulnerable to infections.
How common is a misdiagnosis of COPD?
When you meet with a health professional there is always the chance that you will be assigned a diagnosis (and they often stick). Unfortunately, accuracy of diagnosis is often limited, particularly when the contact is minimal. Complicating the issue of missed diagnosis further is the present trend that encourages and rewards providers for accurately reflecting the intensity of the disease process they treat (doctors are being scored by the "risk acuity factor" or RAF score, a timely subject that deserves a separate discussion).
There is, however, reason for hope. Professional organizations, such as the American Thoracic Society and the European Thoracic Society recently developed The Global Initiative of Obstructive Lung Disease, or GOLD. That resulted in established and universal guidelines for diagnosis, and step-by-step treatment recommendations, according to severity of the disease. GOLD was initiated in 2008, revised in 2011, and is constantly revisited according to evidence-based recommendations. Most primary care physicians are not familiar with GOLD, which explains the large prevalence of misdiagnosis of COPD.
Next up: GOLD Guidelines for COPD