Number of Chronic Medical Conditions Fully Mediates the Effects of Race on Mortality; 25-Year Follow-Up of a Nationally Representative Sample of Americans
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Despite the well-established literature on the effects of race and socioeconomic status (SES) on mortality, limited information exists on mediators of these effects. Taking a life-course epidemiology approach, and using a nationally representative sample of adults in the USA, the current study has two aims: (1) to assess the effects of race and SES at baseline on all-cause mortality over a 25-year follow-up and (2) to test whether the number of chronic medical conditions (CMCs) as a time-varying covariate mediates the effects of race and SES on all-cause mortality.
Data came from the Americans’ Changing Lives (ACL) Study, a nationally representative longitudinal cohort of US adults 25 and older. The study followed 3361 Blacks or Whites for all-cause mortality for up to 25 years from 1986 to 2011. The predictors of interest were race and SES (education and family income) at baseline measured in 1986. Confounders included baseline age and gender. CMC was the potential time-varying mediator measured in 1986, 1989, 1991, 2001, and 2011. We ran Cox proportional hazard models with and without CMC as time-varying covariates.
In separate models, race and SES were predictors of all-cause mortality. In the model that tested the combined effect of race and SES, SES but not race was predictive of all-cause mortality. We also found evidence suggesting that CMC fully mediates the effect of race on all-cause mortality. Number of CMC only partially mediated the effect of SES on mortality.
The number of CMC fully mediates the effects of race and partially mediates the effects of SES on all-cause mortality in the USA. Mortality prevention for minority populations will benefit tremendously from elimination of CMC disparities as well as enhancement of CMC management by minority populations. Elimination of the gap due to SES may be more challenging than the elimination of the racial gap in mortality.
KeywordsRace Socioeconomic status Social class Education Income African-Americans Mortality Chronic medical conditions
Compliance with Ethical Standard
All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) with the Helsinki Declaration of 1975, as revised in 2000. Informed consent was obtained from all participants included in the study. University of Michigan Institutional review board (IRB) approved the study protocol.
Conflict of Interest
Shervin Assari declares that he has no conflicts of interest.
All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) with the Helsinki Declaration of 1975, as revised in 2000. Informed consent was obtained from all participants included in the study.
Shervin Assari designed and analyzed this work and drafted the paper. He also confirmed the last version.
No animal studies were carried out by the authors for this article.
Shervin Assari is supported by the Heinz C. Prechter Bipolar Research Fund and the Richard Tam Foundation at the University of Michigan Depression Center.
- 1.CDC. Chronic Disease Overview 2016. http://www.cdc.gov/chronicdisease/overview/
- 4.Partnership for Solutions. Chronic conditions: making the case for ongoing care: Robert Wood Johnson Foundation; 2002.Google Scholar
- 5.Guralnik JM, LaCroix AZ, Everett DF, Kovar MG. Advance data from vital and health statistics. National Center for Health Statistics. Hyattsville, MD: Aging in the eighties: the prevalence of comorbidity and its association with disability; 1989. p. 170.Google Scholar
- 11.Lawlor DA, Ronalds G, Macintyre S, Clark H, Leon DA. Family socioeconomic position at birth and future cardiovascular disease risk: findings from the Aberdeen Children of the 1950s cohort study. Am J Public Health. 2006;96:1271–7. doi: 10.2105/AJPH.2005.066290.CrossRefPubMedPubMedCentralGoogle Scholar
- 12.Maty SC, Lynch JW, Raghunathan TE, Kaplan GA. Childhood socioeconomic position, gender, adult body mass index, and incidence of type 2 diabetes mellitus over 34 years in the Alameda County Study. Am J Public Health. 2008;98:1486–94. doi: 10.2105/AJPH.2007.123653.CrossRefPubMedPubMedCentralGoogle Scholar
- 15.Assari S. Zivin K. Burgard S. Long-term reciprocal associations between depressive symptoms and number of chronic medical conditions: longitudinal support for black? White Health Paradox. J Racial Ethnic Health Disparities 2015. 2 (2).Google Scholar
- 17.Jackson JS. African American experiences through the adult years. In: Kastenbaum R, editor. The Encyclopedia of Adult Development Phoenix. AZ: Oryx Press; 1993. p. 18–26.Google Scholar
- 22.Centers for Disease Control and Prevention. Death and Mortality. NCHS FastStats Web site. http://www.cdc.gov/nchs/fastats/deaths.htm. Accessed December 20, 2013.
- 28.Gold R, Michael YL, Whitlock EP, Hubbell FA, Mason ED, Rodriguez BL, et al. Race/ethnicity, socioeconomic status, and lifetime morbidity burden in the women’s health initiative: a cross-sectional analysis. J Womens Health (Larchmt). 2006;15:1161–73. doi: 10.1089/jwh.2006.15.1161.CrossRefGoogle Scholar
- 36.Mirowsky J, Ross CE. Education, Social Status, and Health. New York: Aldine de Gruyter; 2003.Google Scholar
- 37.Bowen ME1, González HM. Childhood socioeconomic position and disability in later life: results of the health and retirement study. Am J Public Health. 2010 1;100 Suppl 1:S197-203Google Scholar
- 42.Hummer RA, Lariscy JT. Educational Attainment and Adult Mortality. In: Rogers RG, Crimmins EM, editors. International Handbook of Adult Mortality. New York: Springer Science + Business Media; 2011. pp. 241–61.Google Scholar
- 50.Ross CE, Wu CL. The links between education and health. Am Sociol Rev. 1995;719–745.Google Scholar
- 55.Freese J, Lutfey K. Fundamental causality: Challenges of an animating concept for medical sociology. In: Pescosolido BA, Martin JA, McLeod JD, Rogers A, editors. Handbook of the sociology of health, illness, and healing: A blueprint for the 21st century. New York: Springer; 2011. p. 67–81.Google Scholar
- 56.Link BG, Phelan J. Social conditions as fundamental causes of health inequalities. In: Bird CE, Conrad P, Fremont AM, Timmermans S, editors. Handbook of Medical Sociology. 6th ed. Nashville: Vanderbilt University Press; 2010. p. 3–17.Google Scholar
- 57.Atal S, Cheng C. Socioeconomic health disparities revisited: coping flexibility enhances health-related quality of life for individuals low in socioeconomic status. Health Qual Life Outcomes. 2016;14:7. doi: 10.1186/s12955-016-0410-1
- 62.LaVeist TA. Disentangling race and socioeconomic status: a key to understanding health inequalities. J Urban Health. 2005;82(2 Suppl 3):iii. 26–34.Google Scholar
- 71.Willett WC, Koplan JP, Nugent R, Dusenbury C, Puska P, Gaziano TA. Prevention of chronic diseases by means of diet and lifestyle changes. In: Jamison DT, Breman JG, Measham AR, et al., editors. Disease Control Priorities in Developing Countries. 2nd ed. New York, NY: Oxford U. Press; 2006. p. 833–50. doi: 10.1596/978-0-821-36179-5/Chpt-44.Google Scholar
- 76.Baker R, Camosso-Stefinovic J, Gillies C, Shaw EJ, Cheater F, Flottorp S, et al. Tailored interventions to overcome identified barriers to change: effects on professional practice and health care outcomes. Cochrane Database Syst Rev. 2010;3:CD005470. doi: 10.1002/14651858.CD005470.pub2.Google Scholar
- 78.Rostron BL, Chang CM, Pechacek TF. Estimation of cigarette smoking–attributable morbidity in the United States. JAMA Intern Med. October 13, 2014; doi: 10.1001/jamainternmed.2014.5219.
- 79.US Department of Health and Human Services. How Tobacco Smoke Causes Disease: What It Means to You. Atlanta: US Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health, 2010. Accessed March 24, 2016.Google Scholar
- 81.Liu Y, Croft JB, Wheaton AG, Perry GS, Chapman DP, Strine TW, et al. Association between perceived insufficient sleep, frequent mental distress, obesity and chronic diseases among US adults, 2009 behavioral risk factor surveillance system. BMC Public Health. 2013;13:84.CrossRefPubMedPubMedCentralGoogle Scholar
- 87.Assari S, Sonnega A, Pepin R, Leggett A. Residual effects of restless sleep over depressive symptoms on chronic medical conditions: race by gender differences. J Racial Ethn Health Disparities. 2016 Jan 28. [Epub ahead of print] doi: 10.1007/s40615-015-0202-z.