Researchers study diagnostic error in asthma, COPD

More than 30 million adults in the U.S. have been diagnosed with asthma or chronic obstructive pulmonary disease, which includes emphysema and chronic bronchitis, and many receive daily treatment. However, studies suggest 30 to 50 percent of these patients may have an incorrect diagnosis.

Spirometry is the nationally and internationally recommended test for diagnosing asthma and COPD.

"Despite the clinical guidelines supporting the use of spirometry to identify asthma and COPD, many patients do not receive the test prior to receiving a diagnosis," says Dr. Min Joo, principal investigator on the grant and associate professor of medicine in the UIC College of Medicine.

Spirometry tests lung function by measuring how much and how fast a patient can move air out of the lungs. The patients takes a big breath and exhales as hard and long as possible into a machine.

Joo says that without a spirometry test, patients are at risk for worse sickness and even death, as well as unnecessary medical costs that disproportionately affect African Americans and underserved minority populations.

"A shocking number of patients are misdiagnosed and face a two-fold danger," she said.

"First, they are taking medication for a condition they may not have, creating unnecessary exposure to the side effects and complications of those medications, such as pneumonia from using inhaled corticosteroids. Second, their real conditions are left unidentified and untreated. This may be particularly true for minority and underserved populations who are known to have multi-morbidities and therefore have a number of potential causes for shortness of breath and other breathing-related issues," Joo said.

One study found that up to 65 percent of COPD patients seen in a federally qualified health center turned out not to have COPD when spirometry was later performed.

"In the past, attempts to increase the use of spirometry in a primary care setting have had limited long term success, and a new approach is needed to reduce diagnostic error and better understand its impact on patient safety and outcomes," Joo said. "Our study will test an approach that relies on trained community health workers to facilitate the test, educate patients, and work with primary care physicians."

The Reducing Diagnostic Error to Improve Patient Safety in COPD and Asthma (REDEFINE) study is a three-year clinical trial that will enroll 60 primary care providers and 400 adults who have a diagnosis of asthma and/or COPD but have not had spirometry testing.

One group will receive spirometry testing and be provided with recommended patient education from trained community health workers around the time of their primary care visit. Participants in a control group will receive usual care and education from community health workers, but will not undergo spirometry testing.

Both groups will be followed for one year, at which time the control group will have a spirometry test to confirm their initial diagnosis.

To evaluate the effectiveness of the REDEFINE program, researchers will collect data on the prevalence of diagnostic error, the efficiency of the REDEFINE program's intervention on patient-centered outcomes, and the cost of the program.

"We will look at the key indicators of misdiagnosis and poor outcomes for asthma and COPD," Joo said. "Specifically, we want to track use of respiratory medication, acute visits to primary care physicians, emergency department visits and hospitalizations. We hope to see these numbers reduced for patients who receive our intervention."

Joo hopes her study will illustrate the importance of spirometry testing and help primary care physicians find how best to use spirometry testing for all patients who have breathing issues.