Introduction: CDC Health Disparities and Inequalities Report — United States, 2013

Pamela A. Meyer, PhD1

Paula W. Yoon, ScD2

Rachel B. Kaufmann, PhD2

1Office for State, Tribal, Local and Territorial Support, CDC

2Center for Surveillance, Epidemiology, and Laboratory Services, CDC

Summary

This supplement is the second CDC Health Disparities and Inequalities Report (CHDIR). The 2011 CHDIR was the first CDC report to assess disparities across a wide range of diseases, behavioral risk factors, environmental exposures, social determinants, and health-care access (CDC. CDC Health Disparities and Inequalities Report—United States, 2011. MMWR 2011;60[Suppl; January 14, 2011]). The 2013 CHDIR provides new data for 19 of the topics published in 2011 and 10 new topics. When data were available and suitable analyses were possible for the topic area, disparities were examined for population characteristics that included race and ethnicity, sex, sexual orientation, age, disability, socioeconomic status, and geographic location. The purpose of this supplement is to raise awareness of differences among groups regarding selected health outcomes and health determinants and to prompt actions to reduce disparities. The findings in this supplement can be used by practitioners in public health, academia and clinical medicine; the media; the general public; policymakers; program managers; and researchers to address disparities and help all persons in the United States live longer, healthier, and more productive lives.

Disparities in Health Outcomes and Health Determinants

Health is influenced by many factors. Poor health status, disease risk factors, and limited access to health care are often interrelated and have been reported among persons with social, economic, and environmental disadvantages. The conditions and social context in which persons live can explain, in part, why certain populations in the United States are healthier than others and why some are not as healthy as they could be (1). The World Health Organization (WHO) defines the social determinants of health as the conditions in which persons are born, grow, live, work, and age, including the health-care system (2). According to WHO, "the social determinants of health are mostly responsible for health inequities—the unfair and avoidable differences in health status seen within and between countries" (2). The social determinants of health as well as race and ethnicity, sex, sexual orientation, age, and disability all influence health. Identification and awareness of the differences among populations regarding health outcomes and health determinants are essential steps towards reducing disparities in communities at greatest risk.

Disparities exist when differences in health outcomes or health determinants are observed between populations. The terms health disparities and health inequalities are often used interchangeably. This supplement uses the terms health disparities and inequalities to refer to gaps in health between segments of the population.

Public Health Importance of Health Disparities

The burden of illness, premature death, and disability disproportionately affects certain populations. During the past decade, documented disparities have persisted for approximately 80% of the Healthy People 2010 objectives and have increased for an additional 13% of the objectives (3). Data from the REACH U.S. Risk Factor Survey of approximately 30 communities in the United States indicate that residents in mostly minority communities continue to have lower socioeconomic status, greater barriers to health-care access, and greater risks for, and burden of, disease compared with the general population living in the same county or state (4). Both the 2012 National Healthcare Disparities Report (5) and the 2012 National Healthcare Quality Report (6) found that almost none of the disparities in access to care are improving. In addition, quality of care varies not only across types of care but also across parts of the country (5,6). Disparities in health care access and quality can result in unnecessary direct and indirect costs. According to a 2009 study by the Joint Center for Political and Economic Studies, eliminating health disparities for minorities would have reduced direct medical care expenditures by $229.4 billion and reduced indirect costs associated with illness and premature death by approximately $1 trillion during 2003–2006 (7).

About This Report

This supplement is the second in a series of reports that address health disparities. The 2011 CHDIR was the first CDC report to assess health disparities across a wide range of diseases, behavioral risk factors, environmental exposures, social determinants, and health-care access (8). The 2013 CHDIR includes more current data for 19 of the topics published in 2011. Two 2011 topics, housing and air quality, are not included in 2013 because there were no new data to report. There are 10 new topics. The new topics include: access to healthier food retailers, unemployment, nonfatal work-related injuries and illnesses, fatal work-related injuries, residential proximity to major highways, activity limitations due to chronic diseases, asthma attacks, health-related quality of life, periodontitis in adults, and tuberculosis. In the 2011 CHDIR, the prevalence of asthma (i.e., the percentage of persons who have ever been diagnosed with asthma and still have asthma) was reported, whereas in this report, the characteristics of persons who experienced an asthma attack during the preceding 12 months are discussed. Although the focus of these reports is on the measurement of health disparities, most also mentioned existing evidence-based interventions or strategies.

Criteria for Topic Selection

Selection of new topics for this supplement was done in consultation with CDC's Associate Directors for Science. The primary prerequisites for selection of topics were that data be of high quality and appropriate for developing national estimates. In addition, the topic had to meet one or more of the following criteria: 1) leading cause of premature death, higher disease burden, or lower life expectancy at birth for certain segments of the U.S. population as defined by sex, race/ethnicity, income or education, geography, sexual orientation, and disability status; 2) known determinant of health (e.g., social, demographic, and environmental) where disparities have been identified; and 3) health outcome for which effective and feasible interventions exist where disparities have been identified.

Analysis

Most of the analyses in this supplement are descriptive and did not control for potential confounders or adjust for age; therefore, caution should be used in comparing these findings to findings from studies with different analytical approaches. When data were available and suitable for analysis, disparities were examined for characteristics that included race and ethnicity, sex, age, household income, educational attainment, and geographic location. Other characteristics that were analyzed included place of birth, language spoken at home, disability status, and sexual orientation. Consistent definitions were used as a guide to promote standardization of analyses across the reports. However, readers should be attentive to the definitions used in each report. There are some similarities and some differences in definitions across reports because there are multiple ways to categorize these variables. For certain variables, the most appropriate categorization depends on the topic being studied (e.g., age groups). For other variables, the Office of Management and Budget (OMB) and the U.S. Department of Health and Human Services have set rules that are to be used in federal surveys (i.e., race, ethnicity). To the extent possible, OMB standards were used in the analyses. However, some data sources did not collect or report information with the granularity recommended by OMB because the numbers of some racial and ethnic groups were small and their estimates would not be meaningful. Subject matter experts across CDC participated in identifying appropriate definitions.

Analyses focused on the estimated prevalence of a risk factor or health outcome or on the estimated rate of a health outcome in the population. Also, in certain reports, change in the estimated prevalence or rate over time in recent years was calculated. Analytic methods used in the reports varied; therefore, it is important to read the methods description for each report. Most authors calculated absolute or relative difference in prevalence or rate, or both, between segments of the U.S. population. The absolute difference is the arithmetic difference between two groups. For example, if the prevalence of a certain condition is 1% among women and 5% among men, the absolute difference is 4 percentage points. The relative difference is the absolute difference divided by the value for the referent group; the result is multiplied by 100% to create a percentage. In the above example, the relative difference for men compared with women is 400% ([4%/1%]*100%). In other words, men have an excess prevalence that is four times the prevalence of what occurs among women. This example illustrates that the relative difference can be far larger than the absolute difference, especially when the overall prevalence of the condition is low. Conversely, the relative difference can be smaller when the overall prevalence is high. For example, if the prevalence is 91% among women and 95% among men, the absolute difference is still 4 percentage points but the relative difference is only 4%. To gain a more complete understanding of the population's health status and the impact of disparities, it is instructive to look at both measures.

In most analyses, the statistical significance of observed differences was assessed using formal significance testing with alpha=0.05. If statistical testing was not done, differences were assessed by calculating and comparing 95% confidence intervals (CIs) around the estimated prevalence or rate. In this approach, CIs were used as a measure of variability, and nonoverlapping CIs were considered statistically different. While using CIs in this way is a conservative evaluation of significance differences, infrequently this approach might lead to a conclusion that estimates are similar when the point estimates do differ. Because of analytical constraints, neither statistical significance nor 95% CIs were calculated for three reports (9–11).

Use of This Report

The findings and conclusions in this supplement are intended for practitioners in public health, academia and clinical medicine; the media; general public; policymakers; program managers; and researchers to address disparities and help all persons in the United States live longer, healthier, and more productive lives. The information on disparities can be used to help select interventions for specific subgroups or populations and support community actions to address disparities.

References

1. U.S. Department of Health and Human Services. Healthy People 2020: Disparities. Available at http://healthypeople.gov/2020/about/DisparitiesAbout.aspx.
2. World Health Organization. Social determinants of health. Available at http://www.who.int/social_determinants/sdh_definition/en/index.html.
3. US Department of Health and Human Services. Healthy people 2010 final review. Washington, DC.: U.S. Government Printing Office. 2011.
4. CDC. Surveillance of health status in minority communities—Racial and Ethnic Approaches to Community Health Across the U.S. (REACH U.S.) Risk Factor Survey, United States, 2009. MMWR 2011;60 (No. SS-6).
5. US Department of Health and Human Services. National healthcare disparities report, 2012. AHRQ Publication No. 12-0006. March 2012, Rockville, MD. Available at http://www.ahrq.gov/research/findings/nhqrdr/nhdr11/key.html.
6. US Department of Health and Human Services. National healthcare quality report, 2012. AHRQ Publication No. 13-0003. May 2013, Rockville, MD. Available at http://www.ahrq.gov/research/findings/nhqrdr/nhdr12/nhdr12_prov.pdf.
7. Joint Center for Political and Economic Studies. The economic burden of health inequalities in the United States. 2009. Washington, DC. Available at http://www.jointcenter.org/research/the-economic-burden-of-health-inequalities-in-the-united-states.
8. CDC. CDC Health disparities and inequalities report—United States, 2011. MMWR 2011;60(Suppl; January 14, 2011).
9. CDC. Residential proximity to major highways—United States, 2010. In: CDC Health disparities and inequalities report—United States, 2013. MMWR 2013;62(No. Suppl 3).
10. CDC. Potentially preventable hospitalizations—United States, 2001–2009. In: CDC Health disparities and inequalities report—United States, 2013. MMWR 2013;62(No. Suppl 3).
11. CDC. Tuberculosis—United States, 1993–2010. In: CDC Health disparities and inequalities report—United States, 2013. MMWR 2013;62(No. Suppl 3).