Résumé
Background: It is unclear whether asthma is overdiagnosed in developed countries, particularly among obese individuals, who may be more likely than nonobese people to experience dyspnea. Methods: We conducted a longitudinal study involving nonobese (body mass index 20-25) and obese (body mass index ≥ 30) individuals with asthma that had been diagnosed by a physician. Participants were recruited from 8 Canadian cities by means of random-digit dialing. A diagnosis of current asthma was excluded in those who did not have evidence of acute worsening of asthma symptoms, reversible airflow obstruction or bronchial hyperresponsiveness, despite being weaned off asthma medications. We stopped asthma medications in those in whom a diagnosis of asthma was excluded and assessed their clinical outcomes over 6 months. Results: Of 540 individuals with physician-diagnosed asthma who participated in the study, 496 (242 obese and 254 nonobese) could be conclusively assessed for a diagnosis of asthma. Asthma was ultimately excluded in 31.8% (95% confidence interval [CI] 26.3%-37.9%) in the obese group and in 28.7% (95% CI 23.5%-34.6%) in the nonobese group. Overdiagnosis of asthma was no more likely to occur among obese individuals than among nonobese individuals (p = 0.46). Of those in whom asthma was excluded, 65.5% did not need to take asthma medication or seek health care services because of asthma symptoms during a 6-month follow-up period. Interpretation: About one-third of obese and nonobese individuals with physician-diagnosed asthma did not have asthma when objectively assessed. This finding suggests that, in developed countries such as Canada, asthma is overdiagnosed.
| Langue d'origine | English |
|---|---|
| Pages (de-à) | 1121-1131 |
| Nombre de pages | 11 |
| Journal | CMAJ |
| Volume | 179 |
| Numéro de publication | 11 |
| DOI | |
| Statut de publication | Published - nov. 18 2008 |
Note bibliographique
Funding Information:Competing interests: Shawn Aaron is an advisory board member for AstraZeneca, Boerhinger-Ingelheim, GlaxoSmithKline and Talecris. Louis-Philippe Boulet has served as an advisory board member for AstraZeneca, GlaxoSmithKline, Novartis and Schering-Plough. He has received speaker fees from Altana, AstraZeneca, GlaxoSmithKline, Merck Frosst, Novartis and MedImmune; research funding from AstraZeneca, GlaxoSmithKline, Merck Frosst, Novartis, Schering-Plough, Alexion, AsthmaTx, Boehringer-Ingelheim, Ception, Genentech, IVAX, MedImmune, Topigen and Wyeth; and support for the production of educational materials and initiatives from AstraZeneca, GlaxoSmithKline and Merck Frosst. Andrew McIvor has received honoraria for continuing medical education and for attending advisory boards from AstraZeneca, Boehringer-Ingelheim, GlaxoSmithKline, Novartis, Nycomed, Merck and Graceway. Paul Hernandez has received speaker fees and educational grants from Actelion, AstraZeneca, Boehringer-Ingelheim, GlaxoSmithKline and Pfizer; and consultancy fees from Actelion, Altana, AstraZeneca, Boehringer-Ingelheim, GlaxoSmithKline, Nycomed and Pfizer. No competing interests declared for Katherine Vandemheen, Mark FitzGerald, Catherine Lemiere, Sat Sharma, Stephen Field, Gonzalo Alvarez, Robert Dales, Steve Doucette or Dean Fergusson.
Funding Information:
Funding: This study was funded by the Canadian Institutes of Health Research (grant no. MOP-77520) and the Division of Respiratory Medicine, The Ottawa Hospital. None of the sponsors or funders had any involvement in the design or conduct of the study; the collection, management, analysis or interpretation of the data; or the preparation, review or approval of the manuscript.
ASJC Scopus Subject Areas
- General Medicine