Misdiagnosis Among Frequent Exacerbators of Clinically Diagnosed Asthma and COPD in Absence of Confirmation of Airflow Obstruction.
OBJECTIVE
Clinical diagnosis of severe asthma and chronic obstructive lung disease (COPD) remains a challenge and often flawed with lack of objective confirmation of airflow obstruction (AO). Misdiagnosis of asthma and COPD has been reported in stable disease, data are non-existent in frequent exacerbators. We investigated misdiagnosis and its predictors in frequent exacerbators.


METHODS
The cohort comprised of frequent severe exacerbators (requiring ≥2 emergency room (ER) visits or hospitalizations) of physician diagnosed (PD)-asthma and PD-COPD. All patients underwent a rigorous diagnostic algorithm over a follow-up period of 10 ± 6 months. Two board-certified pulmonologists ascertained final diagnosis. Patients with persistent absence of AO were identified to have misdiagnosis. Multivariate logistic regression analyses were used to identify predictors of misdiagnoses.


RESULTS
Among 333 frequent exacerbators analyzed (171 patients with PD-asthma, 162 with PD-COPD, mean annual exacerbations 3.4 ± 2.8), 24 % of patients had a baseline post-bronchodilator spirometry. Misdiagnosis was found in 26 % (87 of 333) of patients. Another 12 % (41 of 333) of patients had obstructive lung diseases other than asthma and COPD. Independent risk factors for misdiagnosis were spirometry underutilization (PD-asthma: OR = 2.8, 95 % CI 1.16-6.78, p = 0.02 and PD-COPD: OR = 10.7, 95 % CI 2.05-56.27, p = 0.005) and pack years of smoking (PD-COPD: OR = 1.05, 95 % CI 1.01-1.11, p = 0.03).


CONCLUSIONS
Objective confirmation of AO is essential in preventing misdiagnosis in frequent severe exacerbators of clinically diagnosed asthma and COPD, a third of whom have neither. Spirometry utilization is strongly associated with a reduced risk of misdiagnosis. Smoking is associated with increased risk of misdiagnosis in severe COPD, but not asthma.
Division of Pulmonary and Critical Care, University of California, San Francisco-Fresno, 155 N Fresno St, Fresno, CA, 93701, USA, vjain@fresno.ucsf.edu.
Vipul V
VV
Jain
D Richard
DR
Allison
Sherry
S
Andrews
Janil
J
Mejia
Paul K
PK
Mills
Michael W
MW
Peterson
D000328:Adult; D000368:Aged; D001249:Asthma / Q000175:diagnosis* / Q000503:physiopathology; D003951:Diagnostic Errors; D018450:Disease Progression; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000503:physiopathology; D012307:Risk Factors; D012907:Smoking; D013147:Spirometry / Q000706:statistics & numerical data; D014797:Vital Capacity