Education and Income — United States, 2009 and 2011

Gloria L. Beckles, MD1

Benedict I. Truman, MD2

1National Center for Chronic Disease Prevention and Health Promotion, CDC

2National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, CDC

Corresponding author: Gloria L. Beckles, Division of Diabetes Translation, National Center for Chronic Disease Prevention and Health Promotion, CDC. Telephone: 770-488-1272; E-mail: glb4@cdc.gov.

Introduction

The factors that influence the socioeconomic position of individuals and groups within industrial societies also influence their health (1,2). Socioeconomic position has continuous and graded effects on health that are cumulative over a lifetime. The socioeconomic conditions of the places where persons live and work have an even more substantial influence on health than personal socioeconomic position (3,4). In the United States, educational attainment and income are the indicators that are most commonly used to measure the effect of socioeconomic position on health. Research indicates that substantial educational and income disparities exist across many measures of health (1,5–8). A previous report described the magnitude and patterns of absolute and relative measures of disparity in noncompletion of high school and poverty in 2005 and 2009 (9). Notable disparities defined by race/ethnicity, socioeconomic factors, disability status, and geographic location were identified for 2005 and 2009, with no evidence of a temporal decrease in racial/ethnic disparities, whereas socioeconomic and disability disparities increased from 2005 to 2009.

The analysis and discussion of educational attainment and income that follow are part of the second CDC Health Disparities and Inequalities Report (CHDIR) and update information on disparities in the prevalence of noncompletion of high school and poverty presented in the first CHDIR (8). The 2011 CHDIR (9) was the first CDC report to describe disparities across a wide range of diseases, behavioral risk factors, environmental exposures, social determinants, and health-care access. The topic presented in this report is based on criteria that are described in the 2013 CHDIR Introduction (10). The purposes of this analysis are to discuss and raise awareness about group differences in levels of noncompletion of high school and poverty and to motivate actions to reduce these disparities.

Methods

To monitor progress toward eliminating health disparities in the prevalence of noncompletion of high school and poverty, CDC analyzed 2009 and 2011 data from the Current Population Survey (CPS), using methods described previously (8). The CPS is a cross-sectional monthly household survey of a representative sample of the civilian, noninstitutionalized U.S. household population that is conducted jointly by the U.S. Census Bureau and the Bureau of Labor Statistics (11). Data on the continuous income-to-poverty ratio (IPR) in the 2009 and 2011 National Bureau of Economic Research (NBER) data sets based on the March CPS were merged with the March supplement files from the 2009 and 2011 Integrated Public Use Microdata Series — Current Population Surveys (IPUMS-CPS) (12,13).

Self-reported data were collected on various characteristics, including demographic, socioeconomic, and geographic characteristics and place of birth. Group disparities in age-standardized prevalence of noncompletion of high school and poverty were assessed according to sex, race/ethnicity, age, educational attainment, poverty status, disability status, place of birth, world region (country) of birth, U.S. census region of residence, and metropolitan area of residence.

Race/ethnicity categories included non-Hispanic white, non-Hispanic black, American Indian/ Alaska Native, Asian/Pacific Islander, Hispanic, and multiple races. Age groups included 25–44, 45–64, 65–79, and ≥80 years. Educational attainment categories included less than high school, high school graduate or equivalent, some college, and college graduate. Poverty status was derived from the IPR, which is based on family income relative to federally established poverty thresholds that are revised annually to reflect changes in the cost of living as measured by the Consumer Price Index (14).

Disability status was defined by the national data collection standards released by the U.S. Department of Health and Human Services (HHS) in 2011 (15). World region of birth was aggregated to approximate the regions of the world from which the foreign born now originate (16). Absolute and relative disparities in noncompletion of high school were assessed separately for adults aged ≥25 years and 18–24 years; for poverty, disparities were assessed for the total population aged ≥18 years.

Disparities between groups were measured as deviations from a referent category rate. Referent categories were usually those that had the most favorable group estimates for most variables; for racial/ethnic comparisons, white males and females were selected because they were the largest group (17,18). Absolute difference was measured as the simple difference between a group estimate and the estimate for its respective reference category, or referent group. Relative difference, a percentage, was obtained by dividing the absolute difference by the value in the referent category and multiplying by 100. To evaluate changes in disparity over time, relative differences for the groups in 2009 were subtracted from relative differences in 2011 (17,18). The z statistic and a two-tailed test at p<0.05 with Bonferroni correction for multiple comparisons were used to test for the statistical significance of the observed absolute and relative differences and for changes over time. To calculate the standard errors for testing the change over time, a previously described method was used (19), modified to account for the parameter being compared (i.e., relative difference). Statistically significant increases and decreases in relative differences from 2009 to 2011 were interpreted as increases and decreases in disparity, respectively. CDC used statistical software to account for the complex sample design of the CPS and to produce point estimates, standard errors, and 95% confidence intervals. Estimates were age standardized by the direct method to the year 2000 age distribution of the U.S. population (20). Estimates with relative standard error ≥30% were not reported.

Results

In the 2011 population aged ≥25 years, statistically significant absolute disparities in noncompletion of high school were identified for all the characteristics studied (Table 1). Noncompletion of high school increased with age; the absolute differences between the age-specific percentages in the referent group (45–64 years) and the age groups 65–79 years and ≥80 years were 6.6 and 14.8 percentage points, respectively. The absolute racial/ethnic difference between non-Hispanic whites and each of the other racial ethnic groups was highest for Hispanics (30.4 percentage points), lowest for the multiple races group (4.0 percentage points), and intermediate for non-Hispanic American Indian/Alaska Natives (11.6 percentage points), and non-Hispanic blacks (8.8 percentage points). This pattern was similar in both sexes, except that among women, the absolute difference for the multiple races group (3.1 percentage points) was not statistically significant. Absolute differences between the age-standardized percentages of adults who had not completed high school in each poverty status group and the referent group (high income, IPR ≥4) were statistically significant overall and in both men and women. Noncompletion of high school increased with increasing poverty; the absolute difference for the poorest group was approximately three times the absolute difference for the middle-income group (6.4 versus 1.7 percentage points). Significant absolute differences between adults with and without a disability in noncompletion of high school also were found (total: 9.8 percentage points; men: 9.5 percentage points; women: 10.1 percentage points).

Among adults aged ≥25 years in 2011, noncompletion of high school was generally more common among foreign-born than U.S.-born adults (Table 1). Significant absolute differences from the U.S. born were observed in the total population (24.9 percentage points), among non-Hispanic whites (3.1 percentage points), A/PIs (9.0 percentage points), and Hispanics (27.7 percentage points). Disparities in noncompletion of high school also were found according to world region (countries) of birth. In 2011, significant absolute differences were found between persons born in the United States (referent group) and those born in Latin American and Caribbean countries (46.1 percentage points) or in countries in Asia and the Pacific (6.1 percentage points). In 2011, significant absolute differences were also found between residents of the U.S. census regions of the Midwest, South, or West and the referent group (the Northeast). The absolute difference in age-standardized noncompletion of high school between residents who lived inside metropolitan areas and those who lived outside metropolitan areas (referent group) also was significant. In 2009 and 2011, the magnitude and pattern of age, poverty status, and disability differences were similar in men and women. No significant differences were identified in the relative differences of any these characteristics from 2009 to 2011.

Among younger adults aged 18–24 years in 2011, significant disparities in place of birth and in demographic, socioeconomic, disability, and geographic characteristics were found in the age-standardized percentages of adults who did not complete high school (Table 2). Unlike adults aged ≥25 years, the absolute difference between the percentages of young adults who did not complete high school in the younger age group (18–19 years) and older referent group (20–24 years) was significant (33.1 percentage points). The relative difference between persons aged 18–19 years and the referent group increased significantly by 61.6 percentage points from 2009 to 2011, whereas no change occurred from 2009 to 2011 in age-specific disparities in the older population (≥25 years) (Table 1). Among racial/ethnic groups, absolute differences from non-Hispanic whites were only significant among non-Hispanic blacks (7.2 percentage points) and Hispanics (12.4 percentage points), with the magnitude and pattern similar in men and women. Overall, absolute differences in noncompletion of high school between the referent group (high income) and those who lived in poor (4.7 percentage points) or near-poor families (3.6 percentage points) were significant; however, absolute differences were only significant for men in middle-income families and women in poor families. Significant absolute differences in noncompletion of high school also were found among young adults with a disability (15.4 percentage points); however, unlike men aged ≥25 years, the disparity among younger adult men worsened from 2009 to 2011 by 41.1 percentage points. No temporal change in disability disparity was observed among young adult females (Table 2). In 2011, absolute differences in the age-standardized percentage of persons who did not complete high school among those who were foreign born and U.S. born (referent group) were significant in the total population (12.0 percentage points) and among Hispanics (16.0 percentage points). In addition, absolute differences were only significant between U.S.-born young adults and young adults born in Latin American and Caribbean countries (23.4 percentage points). No significant differences were found by U.S. census region or metropolitan area. No significant changes in the U.S. census region disparities occurred from 2009 to 2011.

In 2011, overall and for men and women, significant absolute differences in the age-standardized percentages of adults in poor families (IPR <1.00) were found among the youngest adults, non-Hispanic blacks, and Hispanics; all groups that had not completed college; and adults with disabilities (Table 3). In 2009 and 2011, disparities in poverty increased with decreasing level of educational attainment, with the greatest disparity experienced by the group with the lowest level of educational attainment. Significant absolute differences in the age-standardized percentages in poor families were found between persons of either sex with a disability and those with no disability (referent group) (men: 3.2 percentage points; women 3.5 percentage points). In 2009 and 2011, the absolute differences between persons who were foreign born and U.S. born (referent group) in age-standardized percentages of adults in poor families were significant in the total population (1.7 and 1.6 percentage points, respectively) but not by race/ethnicity. In addition, significant absolute differences also were found between adults born in Latin American and Caribbean countries and those born in the United States. In 2009 and 2011, significant absolute differences in the percentages of adults who lived in poverty were found between residents of the U.S. census regions of the West, South, or Midwest and the referent group (Northeast region) but not between residents who lived inside compared with outside metropolitan areas. From 2009 to 2011, no statistically significant changes in the relative differences in poverty by any characteristic were found (Table 3).

Discussion

The findings in this report indicate that racial/ethnic, socioeconomic, and geographic disparities in noncompletion of high school and poverty persist in the U.S. adult population; little evidence of improvement from 2009 to 2011 was identified. Within each year studied to date, significant absolute and relative differences were found; however, between years, these differences were not statistically different. The pattern of disparities is consistent with sociodemographic and geographic differences reported by several national surveys (6–8,16,21–25). The findings also reveal that young racial/ethnic, foreign-born, and poor adults might be especially vulnerable to early onset and progression of poor health as evidenced by marked disparities in noncompletion of high school among these subgroups.

Educational attainment and income provide psychosocial and material resources that protect against exposure to health risks in early and adult life (1–3). Persons with low levels of education and income generally experience increased rates of mortality, morbidity, and risk-taking behaviors and decreased access to and quality of health care (1,6–8). This report confirms that the lowest levels of education and income are most common and persistent among subgroups that systematically exhibit the poorest health. For example, two out of five Hispanics and nearly one out of five non-Hispanic blacks or American Indian/Alaska Natives had not completed high school, and at least one out of 10 of these racial/ethnic groups had incomes less than the official poverty threshold. However, substantial empirical evidence from the United States and elsewhere consistently shows no thresholds in the relationships between education or income and health. Among children and adults in the overall population and within racial/ethnic groups, rates of mortality, morbidity, and poor health behaviors decrease in a continuous and graded manner with increasing levels of education and income (6,7,23–25).

Health-promotion efforts have emphasized racial/ethnic disparities in health as part of an approach to risk reduction that focuses on groups at high risk, with little or no improvement in disparities (24,26). The patterns described in this report suggest that interventions and policies that are also designed to take account of the influence of educational attainment, family income, and other socioeconomic conditions on health risks in the entire population might prove to be more effective in reducing health disparities (27,28).

Limitations

The findings in this report are subject to at least two limitations. First, all data were self-reported and therefore are subject to recall and social desirability bias. Second, CDC used cross-sectional data for the analyses; therefore, no causal inferences can be drawn from the findings. The limited findings for disparities in place of birth among racial/ethnic groups might reflect small sample sizes in single years of data, as suggested by unstable estimates in the foreign-born strata of several racial/ethnic groups.

Conclusion

The U.S. Department of Education's Institute of Education Sciences recommends effective evidence-based interventions to prevent or reduce the dropout rates among middle school and high school students (29). The U.S. Task Force on Community Preventive Services recommends interventions that promote healthy social environments for low-income children and families and to reduce risk-taking behaviors among adolescents (30). Since 2011, HHS has released several complementary initiatives to eliminate health disparities (26,31). The 2011 HHS action plan focuses specifically on reduction of racial/ethnic disparities but includes education and social and economic conditions among its major strategic areas (26). The 2012 National Prevention Council action plan will implement strategies of the National Prevention Strategy by targeting communities at greatest risk for health disparities, disparities in access to care, and the capacity of the prevention workforce; research to identify effective strategies; and standardization and collection of data to better identify and address disparities. CDC proposes increasing its efforts to eliminate health disparities by focusing on surveillance, analysis, and reporting of disparities and identifying and applying evidence-based strategies to achieve health equity (31). Integration of these efforts across federal departments; among federal, state, and local levels of government; and with nongovernment organizations could increase understanding of how socioeconomic disparities in health arise and persist and provide information on how best to design effective interventions for populationwide and targeted approaches.

References

1. Lynch J, Kaplan G. Socioeconomic position. In: Berkman LF, Kawachi I, eds. Social epidemiology. 1st ed. New York, NY: Oxford University Press; 2000:13–35.
2. Adler NE, Stewart J. Health disparities across the lifespan: meaning, methods, and mechanisms. In: Adler NE, Stewart J, eds. The biology of disadvantage. New York, NY: New York Academy of Sciences; 2010;1186:5–23.
3. Ross CE, Mirowsky J. Neighborhood socioeconomic status and health: context or composition? City Community 2008;7:163–79.
4. Macintyre S, Ellaway A, Cummins S. Place effects on health: how can we conceptualise, operationalise and measure them? Soc Sci Med 2002;55:125–39.
5. Krieger N, Williams DR, Moss NE. Measuring social class in public health research: concepts, methodologies, and guidelines. Annu Rev Public Health 1997;18:341–78.
6. CDC, National Center for Health Statistics. Health, United States, 2011: with special feature on socioeconomic status and health. Hyattsville, MD: CDC, National Center for Health Statistics; 2012.
7. Singh GK, Siahpush M. Trends and disparities in socioeconomic and behavioral characteristics, life expectancy, and cause-specific mortality of native-born and foreign-born populations in the United States, 1979–2003. Int J Epidemiol 2006;35:903–19.
8. CDC. Education and income—United States, 2005 and 2009. In: CDC health disparities and inequalities report—United States, 2011.MMWR 2011;60(Suppl; January 14, 2011).
9. CDC. CDC health disparities and inequalities report—United States, 2011. MMWR 2011;60(Suppl; January 14, 2011).
10. CDC. Introduction. In: CDC health disparities and inequalities report—United States, 2013 MMWR 2013;62(No. Suppl 3).
11. US Census Bureau. Current population survey. Design and methodology. Technical paper 66. Washington, DC: US Census Bureau; October 2006. Available at http://www.census.gov/prod/2006pubs/tp-66.pdf.
12. National Bureau of Economics Research. NBER CPS supplements. Cambridge, MA. Available at http://www.nber.org/data/current-population-survey-data.html.
13. Minnesota Population Center. Integrated public use microdata series—Current Population Survey [Online database]. Version 3.0. Minneapolis, MN: Minnesota Population Center; 2010. Available at http://usa.ipums.org/usa.
14. DeNavas-Walt C, Proctor BD, Smith JC. Current Population Reports. P60-239. Income, poverty and health insurance coverage in the United States: 2010. Washington, DC: US Census Bureau; 2011.
15. US Department of Health and Human Services. Implementation guidance on data collection standards for race, ethnicity, sex, primary language, and disability status. Washington, DC: US Department of Health and Human Services; 2011. Available at http://aspe.hhs.gov/datacncl/standards/ACA/4302/index.pdf.
16. Kandel WA. The U.S. foreign-born population: trends and selected characteristics. Washington, DC: Congressional Research Service; 2011. Available at http://www.fas.org/sgp/crs/misc/R41592.pdf.
17. Keppel K, Pamuk E, Lynch J, et al. Methodological issues in measuring health disparities. Hyattsville, MD: US Department of Health and Human Services, CDC, National Center for Health Statistics. Vital Health Stat 2005;2(141).
18. Keppel KG, Pearcy JN, Klein RJ. Measuring progress in Healthy People 2010. Statistical Notes, No. 25. Hyattsville, MD: National Center for Health Statistics; 2004. Available at http://www.cdc.gov/nchs/data/statnt/statnt25.pdf.
19. US Department of Health and Human Services. Healthy people 2010. Final review. Appendix A: technical appendix. Washington, DC: US Department of Health and Human Services; 2012:A-9–10. Available at http://www.cdc.gov/nchs/data/hpdata2010/hp2010_final_review_technical_appendix.pdf.
20. Anderson RN, Rosenberg HM. Age standardization of death rates: implementation of the year 2000 standard. Natl Vital Stat Rep 1998;47:1–16, 20.
21. Ryan CL, Siebens J. Educational attainment in the United States: 2009. Washington, DC: US Census Bureau; 2012. Current Population Reports Series P20, No. 566.
22. Everett BG, Rogers RG, Hummer RA, Krueger PM. Trends in educational attainment by race/ethnicity, nativity, and sex in the United States, 1989–2005. Ethn Racial Stud 2011;34:1543–66.
23. Ohlshansky SJ, Antonucci T, Berkman L, et al. Differences in life expectancy due to race and educational differences are widening, and may not catch up. Health Aff 2012;31:1803–13.
24. Braveman PA, Cubbin C, Egerter S, Williams DR, Pamuk E. Socioeconomic disparities in health in the United States: what the patterns tell us. Am J Public Health 2010;100(Suppl 1):S186–96. DOI:10.2105/AJPH.2009.166082.
25. Harper S, Lynch J. Trends in socioeconomic inequalities in adult health behaviors among U.S. states, 1990–2004. Public Health Rep 2007;122:177–89.
26. Koh HK, Graham G, Giled SA. Reducing racial and ethnic disparities: the action plan from the Department of Health and Human Services. Health Aff 2011;30:1822–9.
27. Marmot MC, Bell R. Action on health disparities in the United States. JAMA 2009;301:1169–71.
28. Woolf SH, Johnson RE, Phillips RL, Philipsen M. Giving everyone the health of the educated: an examination of whether social change would save more lives than medical advances. Am J Public Health 2007;97:679–83.
29. Dynarski M, Clarke L, Cobb B, Finn J, Rumberger R, Smink J. Dropout prevention: a practice guide (NCEE 2008–4025). Washington, DC: National Center for Education Evaluation and Regional Assistance, Institute of Education Sciences, U.S. Department of Education; 2008. Available at http://ies.ed.gov/ncee/wwc.
30. Task Force on Community Preventive Services. Recommendations to promote healthy social environments. Am J Prev Med 2003;24(3S):S21–4.
31. CDC. Fact sheet: health disparities in education and income. Atlanta, GA: US Department of Health and Human Services, CDC; 2011. Available at http://www.cdc.gov/minorityhealth/reports/CHDIR11/FactSheets/Educationincome.pdf.