Using lung function tests to diagnose COPD can help patients and reduce health care costs

Patients with chronic obstructive pulmonary disease (COPD) would benefit if pulmonary function testing was used more consistently to diagnose the condition, according to a study in CMAJ (Canadian Medical Association Journal)

COPD is the third leading cause of death worldwide and affects more than 10% of adults. Testing airflow with pulmonary function testing is a key tool in diagnosing COPD, but it is underused, with only 30% to 50% of people with physician-diagnosed COPD undergoing testing.

"Given low rates of testing, these findings point to an opportunity to improve patient outcomes, reduce health services use and decrease health care costs by increasing rates of testing for suspected COPD," writes Dr. Andrea Gershon, Sunnybrook Research Institute and Institute for Clinical Evaluative Sciences (ICES), with coauthors.

Researchers looked at data for 68 898 patients diagnosed with COPD between 2005 and 2012, including 16 798 patients with newly diagnosed COPD. Only 41% had received pulmonary function testing, and these patients were more likely to be younger, have seen a specialist and have a primary care physician who followed clinical guidelines for COPD. They were also less likely to have comorbidities.

The researchers found that patients who underwent lung function testing as a diagnostic tool were 10.4% less likely to be hospitalized for COPD or to die of any cause compared with patients who did not undergo testing when other differences between these groups were controlled for. They also found an association between lung function testing and increased use of medication for COPD, a finding consistent with previous research.

"Our results support the commonly held understanding that pulmonary function testing is key to the accurate diagnosis and quality care of people with COPD," state the authors.

They suggest that using this testing more frequently to diagnosis suspected cases of COPD can improve patient outcomes, promote better use of health care services and cut costs.