"Underdiagnosis of COPD was frequent, which suggests a greater need for screening at-risk individuals," write researcher Kylie Hill, PhD, of the University of Toronto, and colleagues in the Canadian Medical Association Journal.
COPD is a progressive and incurable disease that affects the lungs, making it more difficult to breathe. Advancing age and being a heavy smoker or having a history of cigarette smoking significantly increases the risk of developing COPD.
Recent studies have estimated that about 10% of people worldwide over the age of 40 are affected by COPD. In this study, researchers looked at the prevalence of the disease among people with known risk factors.
Researchers screened 1,003 people aged 40 and over who were current or former heavy smokers who visited a primary care clinic for any reason for signs of COPD using spirometry testing. Heavy smoking was defined as a smoking history of 20 pack-years or more. A pack-year is the number of packs smoked per day multiplied by the number of years smoked.
The results showed that 20.7% of the people screened met the criteria for a diagnosis of COPD but only 32.7% had previously been diagnosed with the disease or were aware of their COPD diagnosis.
Researchers say underdiagnosis of COPD has been reported in previous studies, but the extent of it in this study was especially striking given that all of the participants had two major risk factors for COPD.
They say early detection of COPD by screening people at risk, such as older heavy smokers, could offer more effective treatment options and reduce health care costs.