Chronic Obstructive Pulmonary Disease Among Adults — United States, 2011

Chronic obstructive pulmonary disease (COPD) is a group of progressive, debilitating respiratory conditions, including emphysema and chronic bronchitis, characterized by difficulty breathing, lung airflow limitations, cough, and other symptoms. COPD often is associated with a history of cigarette smoking and is the primary contributor to mortality caused by chronic lower respiratory diseases, which became the third leading cause of death in the United States in 2008 (1). Despite this substantial disease burden, state-level data on the prevalence of COPD and associated health-care resource use in the United States have not been available for all states. To assess the state-level prevalence of COPD among adults, the impact of COPD on their quality of life, and the use of health-care resources by those with COPD, CDC analyzed data from the 2011 Behavioral Risk Factor Surveillance System (BRFSS). Among BRFSS respondents in all 50 states, the District of Columbia (DC), and Puerto Rico, 6.3% reported having been told by a physician or other health professional that they had COPD. In addition to the screening question asked of all respondents, 21 states, DC, and Puerto Rico elected to include an optional COPD module. Among persons who reported having COPD and completed the optional module, 76.0% reported that they had been given a diagnostic breathing test, 64.2% felt that shortness of breath impaired their quality of life, and 55.6% were taking at least one daily medication for their COPD. Approximately 43.2% of them reported visiting a physician for COPD-related symptoms in the previous 12 months, and 17.7% had either visited an emergency department or been admitted to a hospital for their COPD in the previous 12 months. Continued surveillance for COPD, particularly at state and local levels, is critical to 1) identify communities that likely will benefit most from awareness and outreach campaigns and 2) evaluate the effectiveness of public health efforts related to the prevention, treatment, and control of the disease.

BRFSS is a state-based, random-digit–dialed telephone survey of the noninstitutionalized, U.S. civilian adult population aged ≥18 years, which is administered annually to households with landline and cellular telephones by state health departments in collaboration with CDC. Response rates for BRFSS are calculated using standards set by the American Association of Public Health Opinion Research response rate formula no. 4.* The response rate is the number of persons who completed the survey as a proportion of all eligible and likely eligible persons. The median survey response rate for all states and DC was 49.7% and ranged from 33.8% to 64.1%. Cooperation rates† ranged from 52.7% to 84.3% (median: 74.2%).

All respondents were asked, "Have you ever been told by a doctor or health professional that you have COPD, emphysema, or chronic bronchitis?" Surveys administered in 21 states,§ DC, and Puerto Rico included additional questions for those who responded "yes." These persons were asked the following questions: "Have you ever been given a breathing test to diagnose your COPD, chronic bronchitis, or emphysema?" "Other than a routine visit, have you had to see a doctor in the past 12 months for symptoms related to shortness of breath, bronchitis, or other COPD, or emphysema flare?" "Did you have to visit an emergency room or be admitted to a hospital in the past 12 months because of your COPD, chronic bronchitis, or emphysema?" "How many different medications do you currently take each day to help with your COPD, chronic bronchitis, or emphysema?" and "Would you say that shortness of breath affects the quality of your life?" Age was standardized to the 2000 U.S. population, and prevalence estimates and 95% confidence intervals (CI) were calculated by state and by selected characteristics. Data were weighted using the new raking method (2). For comparisons of prevalence between subgroups, statistical significance (p<0.05) was determined using t-tests.

Overall, 6.3% of U.S. adults (an estimated 15 million) have been told by a health-care provider that they have COPD (age-adjusted prevalence: 6.0%) (Table 1). Prevalence of COPD increased, from 3.2% among those aged 18–44 years to >11.6% among those aged ≥65 years.

In age-adjusted comparisons, Hispanics were less likely to report COPD than non-Hispanic whites and blacks (4.0% compared with 6.3% and 6.1%, respectively). Women were more likely to report COPD than men (6.7% compared with 5.2%). Respondents who did not have a high school diploma reported a higher prevalence of COPD (9.5%) than those with a high school diploma (6.8%) or some college (4.6%). Respondents who were divorced, widowed, or separated were more likely to report COPD (9.4%) than married respondents (4.6%). Employment status also was related to a reported COPD diagnosis. COPD prevalence was higher among those who were unable to work (20.9%), unemployed (7.8%), or retired (7.6%) than among those who were homemakers or students (4.9%) or who were employed (3.8%). Reported COPD prevalence decreased with increasing household income, from 9.9% among those reporting a household income <$25,000 annually to 2.8% among those reporting ≥$75,000. More current smokers reported having COPD (13.3%) than former smokers (6.8%) or never smokers (2.8%). Respondents with a history of asthma also were significantly more likely to have been diagnosed with COPD (20.3%) than those without asthma (3.8%).

The prevalence of COPD varied considerably by state, from <4% in Puerto Rico, Washington, and Minnesota to >9% in Alabama and Kentucky. The median prevalence by state was 5.8% (range: 3.1%–9.3%). The states in the highest quartile for COPD prevalence clustered along the Ohio and lower Mississippi rivers (Figure). Among the 39,038 respondents with COPD in all states, 36.4% were former smokers, 38.7% were current smokers, and 43.7% had a history of asthma.

Among those 13,306 adults who reported having COPD and who answered the COPD module in 21 states, 76.0% (age-adjusted prevalence: 71.4%) reported having been diagnosed with COPD using a breathing test such as spirometry (Table 2). Among respondents with COPD, having a diagnosis with a breathing test increased with age. The age-adjusted percentage of COPD respondents reporting a breathing test was higher among non-Hispanic whites (71.7%) and non-Hispanic blacks (80.2%) than among Hispanics (58.5%), among those unable to work (82.2%) than among employed adults (67.2%), and among those with a history of asthma (81.4%) than among those without asthma (61.9%). Prevalence of having a breathing test did not differ between COPD respondents by sex, education level, household income, marital status, or smoking status. The age-adjusted percentage of COPD respondents reporting having had a breathing test ranged from 57.3% in Puerto Rico to 81.2% in Nevada, with a median percentage of 73.6%.

Among COPD module respondents, after age adjustment, an estimated 50.8% reported using at least one daily medication to manage their COPD-related symptoms, 41.5% reported seeing a physician for COPD symptoms in the past 12 months, and 18.6% reported a hospital or emergency department visit for their COPD in the previous 12 months (Table 2). Medication use for COPD increased among successive age groups, but no age-related patterns were observed in terms of physician or hospital visits for COPD symptoms. Among COPD module respondents, women were more likely to take daily COPD medications and to have had a physician visit related to COPD than men. Among COPD respondents, the age-adjusted percentages of those taking medication, having physician visits, and having hospital visits related to COPD were higher among those unable to work than for employed adults, were higher among persons also reporting an asthma history than among those without asthma, and declined among successively higher income groups. Taking COPD medications also declined with increasing education level, but visits to a physician or hospital for COPD did not differ by education level. Prevalence of medication use, physician visits, and hospital visits did not differ by race/ethnicity, marital status, or smoking status. The age-adjusted percentage of COPD respondents taking at least one daily COPD medication ranged from 41.4% in Oregon to 64.7% in DC. The percentage having seen a physician in the past 12 months for COPD ranged from 32.4% in Kansas to 50.9% in Utah. The percentage having visited a hospital or emergency department in the preceding 12 months for COPD ranged from 11.7% in Tennessee to 27.1% in Puerto Rico.

A majority (64.2%) of respondents to the COPD module felt that shortness of breath negatively impacted their quality of life (Table 2). No age-related trend was observed, but the age-adjusted percentages of COPD module respondents who reported a negative impact declined with increasing levels of education and income. The percentage was higher among persons who reported being unable to work than among employed persons, was higher among adults who were divorced, widowed, or separated compared with married adults, was higher among those with a history of asthma than among those without asthma, and was higher among current smokers and former smokers than among those who had never smoked. The age-adjusted percentage of COPD respondents who reported a negative impact of shortness of breath on their quality of life did not differ between groups defined by race/ethnicity or sex. The percentage reporting a negative impact of shortness of breath on quality of life ranged from 48.4% in Connecticut to 76.4% in Ohio.

Reported by

Nicole M. Kosacz, MPH, Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee. Antonello Punturieri, MD, Thomas L. Croxton, MD, Monique N. Ndenecho, MPH, James P. Kiley, PhD, Gail G. Weinmann, MD, Div of Lung Diseases, National Heart, Lung, and Blood Institute, National Institutes of Health. Anne G. Wheaton, PhD, Earl S. Ford, MD, Letitia R. Presley-Cantrell, PhD, Janet B. Croft, PhD, Wayne H. Giles, MD, Div of Population Health, National Center for Chronic Disease Prevention and Health Promotion, CDC. Corresponding contributor: Nicole M. Kosacz, nkosacz@cdc.gov, 770-488-5454.

Editorial Note

This is the first report of state-specific prevalence of COPD among adults in all 50 states, DC, and Puerto Rico and the first year in the history of BRFSS that a COPD module was included in the questionnaire. Additionally, this report provides state-level data regarding use of COPD-related health-care resources and COPD's impact on quality of life for selected states and territories. Nationally, 6.3% of adults reported physician-diagnosed COPD. This national average is consistent with results of previous research (3,4). State prevalences varied considerably, ranging from as low as 3.1% in Puerto Rico to as high as 9.3% in Kentucky. The southern states accounted for the highest prevalences of self-reported physician-diagnosed COPD, similar to geographic patterns previously reported for COPD hospitalizations (5) but not for mortality rates (6). Additional research is needed to determine the underlying causes of geographic clusterings, which might be related to geographic variations in other factors, including diagnostic practices, cigarette smoking, access to health care, and occupational and environmental exposures.

The patterns observed with respect to sex, age, race/ethnicity, income, and education are similar to those noted for COPD prevalence, hospitalizations, office visits, and mortality in other reports (4,6). Consistent with the literature, histories of smoking and of asthma were strongly and significantly correlated with COPD. Smoking cessation is important in prevention and also is critical in the management of COPD, given that smoking cessation might slow the decline in lung function associated with COPD (7). Finally, protection for all persons from exposure to secondhand smoke reduces respiratory symptoms of COPD and asthma (8).

This analysis also examined the prevalence of self-reported diagnosis by spirometry (the current standard for diagnosis) on a state-by-state basis. Although spirometry can be performed in a trained physician's office, approximately 20% of those who reported having COPD were not diagnosed with a breathing test. Diagnosis is an important first step, particularly because approximately 63% of U.S. adults with spirometry measurements of poor lung function indicative of COPD have never been diagnosed with COPD (9). In addition, spirometry also can help to stage the severity of disease and help to inform decisions about types of treatment that are appropriate. COPD makes it difficult for persons to work and results in lost wages and work days (10). Symptoms can be severe, and the majority of respondents with COPD asserted that their condition negatively impacts their quality of life. Although no cure for COPD currently exists, COPD is manageable through the use of medication and other interventions (10), which can improve quality of life and decrease lost work time. Of those surveyed, nearly 51% reported using daily medication to manage their COPD symptoms. Further research will have to determine what barriers to diagnosis and treatment exist (e.g., cost of and/or access to health-care resources). Access to health care and insurance coverage are possible issues, given that wide geographic variation was observed in the reporting of spirometry and medication use in this study.

The findings in this report are subject to at least four limitations. First, BRFSS does not include persons from institutionalized settings, including those who are living in nursing or assisted-care facilities. Because COPD is associated with older age, this might result in underestimation of COPD prevalence. Second, COPD diagnosis was based on self-report as opposed to diagnosis using spirometry or review of medical records, possibly leading to underestimation or overestimation of prevalence. Similarly, self-reports of medical tests (e.g., spirometry) and medications also might be underreported or misclassified. Third, cooperation rates ranged from 52.7% to 84.3% (median: 74.2%). Finally, although all states conducted BRFSS surveys for households with cellular telephones only (in addition to the landline samples), not all states administered the optional COPD module as part of their cellular-only sample. However, a comparison of data from landline-only samples with the combined data for the nine states that did administer the module to users of cellular telephones revealed no significant differences in estimates.

The overall prevalence of COPD and its associations with health-care utilization and quality of life make it a serious public health burden that needs to be addressed, especially in areas where the prevalence remains well above the national average. This analysis provides an important starting point for states to quantify the burden of COPD locally and target their resources, as well as to evaluate the effectiveness of education and awareness programs such as the National Heart, Lung, and Blood Institute's "Learn More, Breathe Better" campaign¶ in those states.

References

1. Kochanek KD, Xu J, Murphy SL, Mini?o AM, Kung H. Deaths: final data for 2009. Natl Vital Stat Rep 2011;60(3).
2. CDC. Methodologic changes in the Behavioral Risk Factor Surveillance System in 2011 and potential effects on prevalence estimates. MMWR 2012;61:410–3.
3. Akinbami LJ, Liu X. Chronic obstructive pulmonary disease among adults aged 18 and over in the United States, 1998–2009. National Center for Health Statistics data brief no. 63. Hyattsville, MD: US Department of Health and Human Services, CDC, National Center for Health Statistics; 2011.
4. CDC. Chronic obstructive pulmonary disease surveillance—United States, 1971–2000. MMWR 2002;51(No. SS-6).
5. Holt JB, Zhang X, Presley-Cantrell L, Croft J. Geographic disparities in chronic obstructive pulmonary disease (COPD) hospitalization among Medicare beneficiaries in the United States. Int J Chron Obstruct Pulmon Dis 2011;6:321–8.
6. CDC. Deaths from chronic obstructive pulmonary disease—United States, 2000–2005. MMWR 2008;57:1229–32.
7. Lee PN, Fry JS. Systematic review of the evidence relating FEV1 decline to giving up smoking. BMC Med 2010;8:84.
8. Eisner MD, Balmes J, Yelin EH, et al. Directly measured secondhand smoke exposure and COPD health outcomes. BMC Pulm Med 2006;6:12.
9. Mannino DM, Gagnon RC, Petty TL, Lydick E. Obstructive lung disease and low lung function in adults in the United States: data from the national health and nutrition examination survey, 1988–1994. Arch Intern Med 2000;160:1683–9.
10. Rennard S, Decramer M, Calverley PMA, et al. Impact of COPD in North America and Europe in 2000: subjects' perspective of Confronting COPD International Survey. Eur Respir J 2002;20:799–805.