RT Journal Article SR Electronic T1 Characteristics of Subjects With Undiagnosed COPD Based on Post-Bronchodilator Spirometry Data JF Respiratory Care FD American Association for Respiratory Care SP 63 OP 70 DO 10.4187/respcare.06296 VO 64 IS 1 A1 Hangaard, Stine A1 Kronborg, Thomas A1 Hejlesen, Ole K YR 2019 UL http://rc.rcjournal.com/content/64/1/63.abstract AB BACKGROUND: COPD is largely underdiagnosed. Patients with undiagnosed COPD need to be diagnosed to ensure early treatment institution. It is therefore relevant to obtain a more profound understanding of the characteristics of patients with undiagnosed COPD to improve COPD case finding. This study aimed to explore the characteristics of subjects with undiagnosed COPD from the United States National Health and Nutrition Examination Survey (NHANES) dataset (2007–2012) based on post-bronchodilator spirometry.METHODS: A multitude of statistical tests were performed to explore the potential characteristics of subjects with undiagnosed COPD. A total of 1,098 subjects with a post-bronchodilator FEV1/FVC < 0.7 or lower limit of normal (LLN) were included in the final sample.RESULTS: Undiagnosed subjects experienced less phlegm (P < .001), wheezing (P < .001), and chest pain (P < .001) than subjects diagnosed with COPD. They were characterized by less shortness of breath (P < .001), fewer work/school days lost to wheezing (P < .001), less sleep disturbance (P < .001), and less difficulty socializing (P < .001). The undiagnosed subjects felt less depressed (P < .001). Additionally, they were less likely to have asthma (P < .001). The annual household income was higher among the undiagnosed subjects (P < .001), and they were also characterized by higher FEV1 (P < .001), and FVC (P < .001).CONCLUSIONS: Subjects with undiagnosed COPD were characterized by fewer symptoms and had better lung function than their diagnosed counterparts.