Validation of self-reported chronic obstructive pulmonary disease among patients in the ED.

BACKGROUND: To determine whether the self-reported diagnosis of adults who present to the emergency department (ED) with an acute exacerbation of either asthma or chronic obstructive pulmonary disease (COPD) is validated by medical record review.
METHODS: This is cross-sectional study of 78 consecutive adults, 55 years and older, presenting to 3 EDs with symptoms suggestive of an exacerbation of asthma or COPD. We used current spirometric guidelines for a "spirometrically validated" diagnosis of COPD (eg, postbronchodilator forced expiratory volume in 1 second/forced ventilatory capacity <70%). Patients without office spirometry result were classified with COPD using clinical validation based on at least one of the following: primary care physician diagnosis of COPD, chronic bronchitis, or emphysema in the medical record or chest radiography, chest computed tomography, or arterial blood gas (ABG) diagnostic of COPD.
RESULTS: Among 60 patients who self-reported diagnosis of COPD, 98% (95% confidence interval, 89-100) had clinically validated or spirometrically validated COPD. In addition, 83% (95% confidence interval, 59-96) of patients who reported either asthma only or no respiratory disease had clinically validated or spirometrically validated COPD. In no case was the chest radiograph or the ABG useful as a stand-alone test in establishing the diagnosis of COPD.
CONCLUSIONS: Patients 55 years and older presenting to the ED with acute asthma or COPD, even those with clinical symptoms but no diagnosis of COPD, are likely to have COPD. Clinicians should maintain a high index of suspicion for COPD when older asthma patients deny COPD.