A new study shows that most COPD patients see their doctors about trouble breathing years before they are diagnosed with COPD.

Primary care physicians, patients’ main point of contact in the healthcare field, often miss opportunities to spot chronic obstructive pulmonary disease (COPD).

In fact, new research shows that those doctors may miss the early signs of COPD in up to 85 percent of cases, according to a study published Wednesday in The Lancet.

“The substantial numbers of patients misdiagnosed and under-diagnosed in this study is a cause for concern,” study author Dr. Rupert Jones of Plymouth University Peninsula School of Medicine and Dentistry in the U.K. said in a statement. “It is important that COPD is diagnosed as early as possible so effective treatment can be used to try to reduce lung damage, improve quality of life, and even life expectancy.”

The U.K. Department of Health estimates that 2.2 million people in the U.K. have COPD but are undiagnosed. In the U.S., 12.7 million adults are estimated to have COPD, but close to twice that number live with impaired lung function, suggesting that many more people have COPD but aren’t being diagnosed, according to the American Lung Association.

COPD is a common disease among smokers, characterized by difficulty breathing. It begins with breathing troubles during physical activity, but later leads to difficulty breathing while at rest. COPD is the third leading cause of death in the U.S.

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The British researchers used data from the General Practice and Optimum Patient Care Research databases and identified 38,859 patients over the age of 40 who were diagnosed with COPD between 1990 and 2009. The researchers also looked at the patients’ records for at least two years before and one year after they were diagnosed.

The researchers found that 85 percent of patients had visited their doctors or a care clinic with lower respiratory symptoms at least five years before they were diagnosed. About 58 percent of patients showed signs up to 10 years before diagnosis, and another 42 percent up to 15 years earlier.

To researchers, this shows missed opportunities to investigate a possible COPD diagnosis. These first signs of lung disease should have been investigated through spirometry, or lung function testing, Jones said.

Over the 20 year period, there was a large increase in the use of chest X-rays two years prior to diagnosis, but only a third of patients were given lung function tests.

“Although we have seen small improvements in earlier diagnosis over the past 20 years, many patients are still being diagnosed with severe or very severe airway obstruction, and the average age of diagnosis has fallen only slightly,” the researchers said.

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Besides smokers (including those who have quit), others who have a higher risk of COPD include those older than 40, those with a history of lower respiratory tract complaints, and those with diabetes, cardiovascular disease, and gastroesophageal reflux disease (GERD).

Study co-author Dr. Erika J. Sims of Research in Real Life in Cambridge said their findings show that patients visit doctors and other care providers long before being diagnosed with COPD. Knowing a patient’s risk factors and proper testing can help detect COPD earlier, she said.

“Understanding how to capitalize on these opportunities for earlier diagnosis in the course of routine clinical practice must be a priority for primary care nurses and doctors,” she said.

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