Introduction: Chronic obstructive pulmonary disease (COPD) is a respiratory disease that often goes undiagnosed, particularly in its early stages. Objective: To examine sociodemographic, general health, and COPD specific factors, including severity of lung obstruction, that are associated with healthcare provider-diagnosed COPD among U.S. adults. Methods: NHANES cross-sectional data collected from 2007-2012 on adults aged 40-79 years (n=10,219) were analyzed. The primary outcome was self-reported COPD diagnosis with predictive factors analyzed via chi-square and logistic regression analyses. Results: During 2007-2012, 5.2% of US adults aged 40-79 reported being diagnosed with COPD. Among those diagnosed, 50.8% reported fair or poor health, 47.1% were currently smoking cigarettes, 49.1% were taking prescription respiratory medication, 36.4% had moderate or worse lung obstruction, and nearly 90% had one or more respiratory symptoms. Logistic regression revealed positive associations between receiving a COPD diagnosis and the following: being white (AOR: 3.08, 95% CI: 1.82-5.20); being aged 60-79 years (AOR: 1.65, 95% CI: 1.07-2.53); reporting fair/poor health (AOR: 2.91, CI: 1.55-5.46); having 4-9 (AOR: 3.5, CI: 1.3-9.4) or 10 or more healthcare visits in prior year (AOR: 5.06, CI: 1.62-15.77); being a former (AOR: 1.75, CI: 1.2-2.5) or current smoker (AOR: 1.70, CI: 1.17-2.48); having more severe lung obstruction (AOR: 4.90, CI: 3.28-7.32); having 3 or more respiratory symptoms (AOR: 22.07, CI: 12.03-40.49). Conclusions: Multiple factors are associated with self-reported COPD diagnosis with number of reported respiratory symptoms having the strongest association. After controlling for other factors, having mild lung obstruction was not associated with being diagnosed.

BACKGROUND: National Asthma Education and Prevention Program (NAEPP) guidelines recommend that periodic spirometry be performed in youth with asthma. NAEPP uses different spirometry criteria to define uncontrolled asthma for children (6-11 years) and adolescents (12+ years). OBJECTIVE: To describe differences in spirometry between US children and adolescents with current asthma. METHODS: We examined cross-sectional spirometry data from 453 US youth with current asthma age 6-19 years from the 2007-2010 National Health and Nutrition Examination Surveys. The main outcomes were percentage predicted forced expiratory volume at 1 sec (FEV1%) ≤80 and the ratio of FEV1 to forced vital capacity (FEV1/FVC) ≤0.80. We also examined the prevalence of youth with spirometry values consistent with uncontrolled asthma, using NAEPP age-specific criteria, defined for children aged 6-11 years as FEV1% ≤80 or FEV1/FVC ≤0.80, and for adolescents aged 12-19 years as FEV1% ≤80. RESULTS: Children 6-11 years and adolescents 12-19 years did not differ in prevalence of FEV1% ≤80 (10.1% vs. 9.0%) or FEV1/FVC ≤0.80 (30.6% vs. 29.8%). However, based on the NAEPP age-specific criteria, 33.0% of children 6-11 years and 9.0% of adolescents 12-19 years had spirometry values consistent with uncontrolled asthma (P < 0.001). CONCLUSION: Children 6-11 years and adolescents 12-19 years with current asthma did not differ in the percentage with FEV1% ≤80 or FEV1/FVC ≤0.80. However, the percent of children and adolescents with spirometry values consistent with uncontrolled asthma did differ. The difference appears to stem mainly from the different spirometry criteria for the two age groups.

BACKGROUND: The study evaluated the change in the prevalence of airflow obstruction in the U.S. population 40-79 years of age from years 1988-1994 to 2007-2010. METHODS: Spirometry data from two representative samples of the U.S. population, the National Health and Nutrition Examination Surveys (NHANES) conducted in 1988-1994 and 2007-2010, were used. The American Thoracic Society/European Respiratory Society (ATS/ERS) criteria were used to define airflow obstruction. RESULTS: Based on ATS/ERS criteria, the overall age-adjusted prevalence of airflow obstruction among adults aged 40-79 years decreased from 16.6% to 14.5% (p < 0.05). Significant decreases were observed for the older age category 60-69 years (20.2% vs. 15.4%; p < 0.01), for males (19.0% vs. 15.4%; p < 0.01), and for Mexican American adults (12.7% vs. 8.4%; p < 0.001). The prevalence of moderate and more severe airflow obstruction decreased also (6.4% vs. 4.4%; p < 0.01). Based on ATS/ERS criteria, during 2007-2010, an estimated 18.3 million U.S. adults 40-79 years had airflow obstruction, 5.6 million had moderate or severe airflow obstruction and 1.4 million had severe airflow obstruction. CONCLUSIONS: The overall age-adjusted prevalence of airflow obstruction among U.S. adults aged 40-79 years decreased from 1988-1994 to 2007-2010, especially among older adults, Mexican Americans, and males.

BACKGROUND: During 2007-2010, the National Health and Nutrition Examination Survey (NHANES) conducted a spirometry component which obtained pre-bronchodilator pulmonary lung function data on a nationally representative sample of US adults aged 6-79 years and post-bronchodilator pulmonary lung function data for the subset of adults with airflow limitation. The goals of this study were to 1) compute prevalence estimates of chronic obstructive pulmonary disease (COPD) using pre-bronchodilator and post-bronchodilator spirometry measurements and fixed ratio and lower limit of normal (LLN) diagnostic criteria and 2) examine the potential impact of nonresponse on the estimates. METHODS: This analysis was limited to those aged 40-79 years who were eligible for NHANES pre-bronchodilator spirometry (n=7,104). Examinees with likely airflow limitation were further eligible for post-bronchodilator testing (n=1,110). Persons were classified as having COPD based on FEV1/FVC < 70% (fixed ratio) or FEV1/FVC < lower limit of normal (LLN) based on person's age, sex, height, and race/ethnicity. Those without spirometry but self-reporting both daytime supplemental oxygen therapy plus emphysema and/or current chronic bronchitis were also classified as having COPD. The final analytic samples for pre-bronchodilator and post-bronchodilator analyses were 77.1% (n=5,477) and 50.8% (n=564) of those eligible, respectively. To account for non-response, NHANES examination weights were adjusted to the eligible pre-bronchodilator and post-bronchodilator subpopulations. RESULTS: In 2007-2010, using the fixed ratio criterion and pre-bronchodilator test results, COPD prevalence was 20.9% (SE 1.1) among US adults aged 40-79 years. Applying the same criterion to post-bronchodilator test results, prevalence was 14.0% (SE 1.0). Using the LLN criterion and pre-bronchodilator test results, the COPD prevalence was 15.4% (SE 0.8), while applying the same criterion to post-bronchodilator test results, prevalence was 10.2% (SE 0.8). CONCLUSIONS: The overall COPD prevalence among US adults aged 40-79 years varied from 10.2% to 20.9% based on whether pre- or post-bronchodilator values were used and which diagnostic criterion (fixed ratio or LLN) was applied. The overall prevalence decreased by approximately 33% when airflow limitation was based on post-bronchodilator as compared to pre-bronchodilator spirometry, regardless of which diagnostic criterion was used.

PURPOSE: To describe the frequency doubling technology (FDT) methodology to measure visual field loss in the National Health and Nutrition Examination Survey and to evaluate data reliability. METHODS: Participants aged 40 years and older were eligible (n = 2,529) for 2 visual field tests per eye performed with the Humphrey Matrix N-30-5 screening test. Visual field loss was determined using a 2-2-1 algorithm requiring 2 complete tests per eye, with at least 2 abnormal field results in each test, and 1 common abnormal field. RESULTS: Response rate was 86.2%. Time constraints were the main reason for no exam (55.6%). Median times were: single test, 37 seconds; entire exam, 9.1 minutes. When defining reliability based on ≤ 1/3 blind spots, ≤ 1/3 false positive tests, and technician noted proper fixation, 80.1% of examined adults had 2 reliable tests for both eyes; an additional 13.4% had 2 reliable tests for 1 eye. Increasing age, decreasing visual acuity, and the presence of self-reported glaucoma resulted in decreased examination rates, increased test times, and decreased data reliability. Sensitivity and specificity to detect persons with glaucoma was 54.8% and 91.9%, respectively. CONCLUSIONS: FDT is a feasible, fast, and reliable method for visual field loss screening in a population-based U.S. study, with an 86.2% response rate, median exam time ~9 minutes, and nearly 95% of examined participants having complete, reliable results in 1 or both eyes.