New research from Canada shows that one-third of people with asthma can safely stop medication. This diagnosis is also often incorrect in the Netherlands.
“Stopping without symptoms”
A total of 613 people who had been diagnosed with asthma in the past 5 years participated in the study [1].
The medication was slowly tapered off, and the participants were retested, including lung function tests. They were then followed for another year. Asthma could ultimately be ruled out in 203 participants. Tapering off the medication did not result in (worsened) symptoms. A small number (12) were found to have a condition other than asthma.
Of those 203 participants who were found not to have asthma, this may have changed since the diagnosis was made, or the diagnosis was incorrect. An example of a misdiagnosis is that of a 72-year-old former nurse who was diagnosed with asthma. It turned out she had been temporarily short of breath due to pneumonia.
Approximately half of the participants had undergone a lung function test at the initial diagnosis. In other cases, the diagnosis was based on symptoms and not confirmed by a test. In cases where the diagnosis was incorrect, the percentage that had undergone the so-called spirometry test was lower (43.8% vs 55.6%). The researchers therefore advise always confirming the diagnosis based on symptoms with a test. However, it should be noted that the spirometry test apparently does not provide certainty either.
Netherlands: “Half of children don’t actually have asthma”
The work of the Canadians followed earlier research indicating that in a large number of cases, the diagnosis of asthma is incorrect in adults [2]. I wondered how this situation was in the Netherlands and contacted the Longfonds. The Longfonds referred to research conducted locally [3].
The UMC Utrecht examined 5000 children aged 6 to 18 and concluded that half of them did not have asthma. The difference with the Canadian figures may partly be due to the difficulty of testing for asthma in children under 6 years old.
“That can be improved,” thought researchers at the AMC. They developed the ‘E Nose’, a diagnostic tool that can ‘smell’ lung diseases [4]. Currently, this tool is being tested by various Dutch hospitals and general practitioners on 3000 patients to measure more accurately.
References
- Aaron SD, Vandemheen KL, FitzGerald JM, Ainslie M, Gupta S, Lemière C, Field SK, McIvor RA, Hernandez P, Mayers I, Mulpuru S, Alvarez GG, Pakhale S, Mallick R, Boulet L, for the Canadian Respiratory Research Network. Reevaluation of Diagnosis in Adults With Physician-Diagnosed Asthma. JAMA. 2017;317(3):269-279. doi:10.1001/jama.2016.19627
- Aaron, Shawn D. et al. “Overdiagnosis of Asthma in Obese and Nonobese Adults.” CMAJ : Canadian Medical Association Journal 179.11 (2008): 1121–1131. PMC. Web. 27 Jan. 2017.
- longfonds.nl/nieuws/helft-van-de-kinderen-met-astma-heeft-toch-geen-astma
- longfonds.nl/nieuws/e-nose-die-longziekten-ruikt-komt-naar-spreekkamer
