TY - JOUR T1 - Overdiagnosis of asthma in obese and nonobese adults JF - Canadian Medical Association Journal JO - CMAJ SP - 1121 LP - 1131 DO - 10.1503/cmaj.081332 VL - 179 IS - 11 AU - Shawn D. Aaron MD AU - Katherine L. Vandemheen, BScN AU - Louis-Philippe Boulet MD AU - R. Andrew McIvor MD AU - J. Mark FitzGerald MD AU - Paul Hernandez MD AU - Catherine Lemiere MD AU - Sat Sharma MD AU - Stephen K. Field MD AU - Gonzalo G. Alvarez MD AU - Robert E. Dales MD AU - Steve Doucette, MSc AU - Dean Fergusson, PhD A2 - , Y1 - 2008/11/18 UR - http://www.cmaj.ca/content/179/11/1121.abstract N2 - 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. ER -