View Abstract

A3546 - Validity of Self-Reported Health Professional Diagnosed Chronic Obstructive Pulmonary Disease (COPD) — National Health and Nutrition Examination Survey (NHANES) 2007-2012
Author Block: K. A. Clark1, J. M. Mazurek2; 1Respiratory Health Division, CDC/National Institute for Occupational Safety and Heath, Morgantown, WV, United States, 2CDC/ NIOSH, Morgantown, WV, United States.
RATIONALE: Surveys collect self-reported information on a doctor or other health care professional diagnosed emphysema and chronic bronchitis. Researchers and public health agencies use these data to estimate COPD prevalence, its associations with health-care utilization and quality of life, and to determine priorities for interventions. Limited information is available on the validity of self-reported physician-diagnosed COPD against objective pulmonary function testing. METHODS: To examine the validity of self-reported physician-diagnosed COPD against spirometry test results data from 2007-2012 NHANES medical questionnaire and spirometry examination for adults aged 20-79 years were analyzed. Survey participants with physician-diagnosed COPD were identified using affirmative responses to the questions “Has a doctor or other health professional ever told you that you had emphysema / chronic bronchitis?” Airflow obstruction was determined when pre-bronchodilator forced expiratory volume at one second (FEV1)/forced vital capacity (FVC) ratio was below the estimated NHANESIII lower limit of normal (LLN). LLN estimates were adjusted for age, sex, and race/ethnicity. Only spirometry tests with at least two acceptable and repeatable maneuvers (i.e., the two largest FEV1 maneuver volumes were within 200 mL) were analyzed. Weighted estimates were used to calculate sensitivity, specificity, positive predictive value and negative predictive value. RESULTS: Among 29,353 survey participants, 12,859 (43.8%) were aged 20-79 years, performed spirometry testing of acceptable quality, and responded to questions on emphysema / chronic bronchitis diagnoses. An estimated 5.9% (95%CI: 4.9, 6.8) persons self-reported physician-diagnosed COPD. The prevalence of spirometry-defined airflow obstruction was 12.1% (95%CI: 11.3, 12.8). Compared with spirometry-defined airflow obstruction, the self-reported physician-diagnosed COPD had low sensitivity (11.5%) and positive predicted value (23.7%), moderately high specificity (94.9%), and moderately high negative predictive value (88.6%). The odds for confirming COPD through spirometry were 2.4 times greater (95%CI: 2.0, 3.0) when participants reported a physician-diagnosis of COPD. CONCLUSIONS: The use of a questionnaire may underestimate COPD prevalence. Results suggest that many individuals may not know they have COPD, COPD may be misdiagnosed, or participants may incorrectly recall the diagnosis. Nevertheless, if a participant reported a previous COPD diagnosis, they were significantly more likely to perform spirometry testing indicative of obstructive ventilatory impairment.