Ottawa, Canada—Many adults filling prescriptions for asthma drugs likely were misdiagnosed and don’t even have the respiratory ailment, according to a new study.
The report, published in the Journal of the American Medical Association, points out that, in a recent study, 33% of adults recently diagnosed with asthma by their physicians did not have active asthma.
The University of Ottawa–led study team adds that more than 90% of those patients were able to stop their asthma medications and remain safely off medication for at least one year.
“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impossible to say how many of these patients were originally misdiagnosed with asthma, and how many have asthma that is no longer active,” said lead author Shawn Aaron, MD, senior scientist and respirologist at The Ottawa Hospital and professor at the University of Ottawa. “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 study found that 80% of the participants determined to not have asthma were taking medications for the condition, with 35% using it daily.
The problem, according to the study, is that physicians routinely fail to order tests required to confirm an asthma diagnosis, instead basing their diagnoses solely on the patient's symptoms and their own observations.
“Doctors wouldn’t diagnose diabetes without checking blood sugar levels or a broken bone without ordering an x-ray,” Aaron asserted. “But for some reason many doctors are not ordering the spirometry tests that can definitely diagnose asthma.”
The study looked at 613 randomly selected patients diagnosed with asthma in the last 5 years in 10 Canadian cities. After undergoing a series of detailed breathing tests, followed by consultation with a lung specialist and tapering off any asthma medications, a current diagnosis of asthma was ruled out in a third of the patients.
Available medical records for 530 of the participants indicate that physicians had not ordered airflow tests required by medical guidelines in 49% of the cases. Re-diagnosis found that most of the patients previously told they had asthma had, instead, minor conditions like allergies or heartburn.
While 28% percent had nothing wrong with them at all, 2% had serious conditions such as pulmonary hypertension or heart disease that had been misdiagnosed as asthma and subsequently received proper treatment, according to the report.
“It wasn’t a surprise to most patients when we told them they didn’t have asthma,” Aaron explained. “Some knew all along that their puffer wasn’t working, while others were concerned that they might have something more serious. Thankfully, the majority of the conditions were mild and easily treated.”
Study authors note that “two phenomena may account for failure to ultimately confirm current asthma in 33.1% of the study cohort: (1) spontaneous remission of previously active asthma; and (2) misdiagnosis of asthma in the community. At least 24 of 203 participants (11.8%) in whom current asthma was ruled out had undergone pulmonary function tests in the community that had been previously diagnostic of asthma. These participants presumably experienced spontaneous remission of their asthma at some time between their initial community diagnosis and entry into the study.”
The solution, according to Aaron, is educating “physicians and the public to get the diagnosis right in the first place. 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.”
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