As many as 1 in 3 people diagnosed by physicians as having asthma may not have the respiratory disease, a Canadian study suggests.
The finding is concerning because it suggests that millions of people may be taking asthma medications unnecessarily.
“It’s impossible to say how many of these patients were originally misdiagnosed with asthma, and how many have asthma that is no longer active,” said Shawn Aaron, M.D., a respirologist at The Ottawa Hospital and lead author of the study. “What we do know is that they were all able to stop taking medication that they didn’t need – medication that is expensive and can have side effects.”
The Canadian study examined 613 people whose physicians had diagnosed them with asthma during the previous five years. Exams found that 203 of them – one-third – did not have asthma at the time of the follow-up. Some may have seen their cases of asthma subside since the diagnosis. Others were misdiagnosed in the first place.
Tellingly, only about 44 percent of the patients who did not currently have asthma were originally diagnosed with a breathing airflow test, such as by breathing into a spirometer. Such testing might have ruled out an asthma diagnosis.
Dr. Aaron’s call to action
For Dr. Aaron, the results make clear the importance of getting the correct diagnosis.
“We need to educate physicians and the public to get the diagnosis right in the first place,” he said. “Patients who have difficulty breathing should ask their doctor to order a breathing test (spirometry) to determine if they might have asthma or even Chronic Obstructive Pulmonary Disease (COPD). Similarly, if patients think they may have been misdiagnosed with asthma or that they no longer have asthma, they should ask their doctor for a spirometry test. Asthma can be deadly, so patients should never go off their medication without speaking to a doctor first.”
Asthma is a disease that limits the lungs’ ability to transfer air into and out of the body. About 17.7 million Americans, or more than 7.4 percent of the population, have the disease, according to the U.S. Centers for Disease Control and Prevention. In 2014, it killed 3,651 people.
- Coughing at night or early morning
- Tightness in the chest
People with asthma have it all the time, but asthma attacks occur when the lungs are irritated. An asthma attack causes the airways to tighten, further limiting the flow of air to and from the lungs.
Asthma is treated with various medications. Some can be breathed in through an inhaler. Some are aimed at relieving the symptoms of an attack. Others are intended for long-term control of the disease.
The Asthma and Allergy Foundation of America estimates the direct cost of asthma – medications, hospitalizations and treatments – at about $50.1 billion a year. Medicaid spent about $67 per member on asthma medicine in 2014, the program’s third-highest category of treatment.
Discuss your asthma-like symptoms – or disappearance of them – with your health care provider. You can find a Providence provider near you in our directory.
Resources in this article
The Canadian study, “Reevaluation of Diagnosis in Adults With Physician-Diagnosed Asthma,” was published in the Journal of the American Medical Association. The Ottawa Hospital published a news release about the findings.
The CDC’s asthma resource page provides management techniques, statistics and other information.