One-third of asthma patients may be misdiagnosed
Approximately one-third of adults with previously diagnosed asthma may not have a current diagnosis.
About one-third of adults with physician-diagnosed asthma within the previous 5 years had no evidence of current asthma, according to a study published in JAMA.
Shawn D. Aaron, MD, from the Ottawa Hospital Research Institute, Ottawa Hospital, University of Ottawa, and colleagues conducted a multicenter, cohort study in 10 Canadian cities from January 2012 to February 2016 to determine whether a diagnosis of current asthma could be ruled out to safely stop medications in randomly selected adults with physician-diagnosed asthma.
The investigators used random digit dialing to recruit 701 eligible adult participants who reported a history of physician-diagnosed asthma within the previous 5 years. They obtained information from the diagnosing physician to determine how the diagnosis of asthma was made.
The participants were assessed with home peak flow and symptom monitoring, spirometry, and serial bronchial challenge tests. Participants using daily asthma medications had their medications gradually tapered off over 4 study visits. Those who had a current asthma diagnosis ruled out were followed up clinically with repeated bronchial challenge tests over 1 year.
A current diagnosis of asthma was ruled out if participants exhibited no signs of acute worsening of asthma symptoms, reversible airflow obstruction, or bronchial hyperresponsiveness after having all asthma medications tapered off and after a pulmonologist established another diagnosis.
Current asthma was ruled out in 33.1% of study participants. In addition, 12 participants (2.0%) had serious cardiorespiratory conditions that were previously misdiagnosed as asthma.
After an additional 12 months of follow-up, 29.5% of participants continued to exhibit no clinical or laboratory evidence of asthma. Researchers found that 43.8% of participants in whom asthma was ruled out had undergone assessment of airflow limitation compared with 55.6% of participants who had confirmed current asthma.
“The study demonstrated that failure to consistently use objective testing at the time of initial diagnosis of asthma was associated with failure to confirm current asthma,” the study authors wrote. “These results suggest that whenever possible, physicians should order objective tests, such as prebronchodilator and postbronchodilator spirometry, serial peak flow measurements, or bronchial challenge tests, to confirm asthma at the time of initial diagnosis.”
- Aaron SD, Vandemheen KL, FitzGerald JM, et al. Reevaluation of diagnosis in adults with physician-diagnosed asthma. JAMA. 2017;317(3):269-279. doi:10.1001/jama.2016.19627