“Of all of the forms of inequality, injustice in health is the most shocking and inhumane.”
—Dr. Martin Luther King, Jr. (1929–1968)
Chronic kidney disease (CKD) has recently become recognized as a global public health problem.1–3 CKD and, to a greater extent, ESRD are characterized by marked differences in incidence, prevalence, and/or complications across gender, age, race/ethnicity, socioeconomic status, and geographic boundaries. These traits may confer either protection or increased risk for certain health practices and medical conditions, suggesting there is much to learn beyond the traditional risk factors contributing to CKD and CKD-associated complications.4–7 ESRD is one of the most dramatic examples of health disparities, with rates for minorities ranging from 1.5 to 4.0 times those of age-adjusted white counterparts,6 despite similar rates for the early stages of CKD.8 Although CKD is associated with increased rates of premature mortality,9,10 adjusted ESRD survival rates are paradoxically better for minorities.11 The Institute of Medicine notes that inequities in health outcomes can arise from within the health care system, such as the operation of health care systems, and the legal and regulatory climate or from ecologic factors, such as clinical appropriateness and need, and patient preferences, although significant overlap exists, for example, discrimination, biases and prejudice, stereotyping, and uncertainty. The Institute of Medicine defines disparities in health care as differences that generally represent institutional or provider biases that are unjust, even if unintentional (Figure 1).12,13 Unfortunately, the contribution of factors such as patient beliefs and preferences are commonly overlooked when ascribing disparities to health care systems and/or providers.
The term “health disparities,” however, is frequently used to describe the adverse health outcomes experienced by racial/ethnic minorities that occur in the context of broad historic and contemporary social and economic inequality,14–16 as well as health care system factors.12,17–19De facto racial segregation remains prevalent within US health care systems, while limited revenues and reduced capacity for health care delivery constrain organizations dedicated to the care of poor and often largely minority populations.20 Residential segregation, which was federal policy up to the civil rights movement21 and continues today as mortgage discrimination, leads to racially divided communities that may share low-income status but often differ in wealth, community assets, exposure to heavy metals or excess ambient air particulate matter, and other variables that may influence CKD-related outcomes.22,23 Geographic analyses revealed community-level poverty was strongly associated with higher ESRD incidence but was a more powerful predictor for black than for white individuals.24 Dialysis facilities located in predominantly black communities have higher mortality rates and lesser compliance with recommended performance targets.25 As we refine our understanding of health disparities, we might be able to move beyond the racial and ethnic background as the defining risk for CKD progression and directly target the underlying biologic and sociocultural factors for which race and ethnicity may be surrogates.
WHY FOCUS ON HEALTH DISPARITIES?
As the recognized world leader in health technology and medical care, the persistence of health inequities in the United States is an indictment of the institutionalization of moral apathy and likely contributes to our new ranking as last in preventable deaths among developed nations.26 Dr. Steven Schroeder, former president of the Robert Wood Johnson Foundation, presents a compelling case for concentrating strategies on the less fortunate to improve the health of the American people noting “that since all of the actionable determinants of health—personal behavior, social factors, health care, and the environment—disproportionately affect the poor, strategies to improve national health rankings must focus on this population.”27
One challenge for the nephrology community as well as the broader medical community is to rethink how we might improve each element that conspires to constrain the health outcomes we are trying to achieve, not just those limited to a procedure or prescription. The focus of this review is to bring greater awareness of and discuss strategies to address some of the key social and environmental factors that contribute to CKD disparities and improve US health care systems to care effectively for an increasingly diverse CKD patient population.
CULTURAL, ENVIRONMENTAL, AND SOCIOECONOMIC INFLUENCES ON HEALTH OUTCOMES
“It is much more important to know what sort of a patient has a disease, than what sort of disease a patient has.”
—William Osler (1849–1919)
Further complicating strategies for effective health care delivery are the multiple variations in health beliefs and practices, as well as distrust of the health care system, that extend across many of the nation's socioeconomic and culturally diverse communities.28 In addition, the health care milieu is under increasing pressure to provide more comprehensive quality care in shorter visit times to more people and with more documentation while using fewer resources. The likelihood of overt or subtle conflicts between patients and providers/health care systems is markedly increased under such settings. Addressing the constellation of factors that influence health outcomes seems an arduous task for health care providers, yet it is health care providers, most commonly physicians, to whom the general community looks for leadership, not just for medical care, but for broader issues that affect health and well-being. For grasping more easily the multidimensional nature of CKD disparities, a theoretical framework can assist in understanding how the many sociocultural and environmental elements interact with biology to influence the initiation and progression of CKD (Figures 2 and 3),23,29 as well as understanding the context of patient-specific needs, values, and preferences (Tables 1 and 2).30
Although understanding some of the broad differences in values can enhance our sensitivity and compassion for those we see as different from ourselves, patient-centered care reminds us that it is also important not to generalize and use a “one size fits all” approach. Increased acculturation and integration both across and within racial/ethnic and socioeconomic boundaries have led to diffusion and/or assimilation of the many values commonly attributed to a specific group. Nonetheless, the insight into the origin and existence of such values is important in enabling a better understanding of “what sort of patient has a disease.”
BIOLOGY AND VARIATIONS IN HEALTH OUTCOMES
Specific to CKD are marked variations in the prevalence of key risk factors such as diabetes, hypertension, and albuminuria across socioeconomic, gender, and racial/ethnic groups that play an important role in group differences in the prevalence, progression, and complications of CKD.31–36 Although there may be biologic variations among racial and ethnic groups, the emerging data from the human genome project suggest that these interracial variations are modest at best and much smaller than intraracial variations.37,38 Indeed, biologic variations are more common across gender than race/ethnicity. Select biologically based factors may have both racial and nonracial contributions, such as hypovitaminosis D, which may be related to increased melanin and reduced ultraviolet conversion of previtamin D as well as nutritional deficiency. Hypovitaminosis D is associated with increased rates of CKD initiation factors such as hypertension and diabetes39 and progression factors such as inflammation and fibrosis,40 whereas vitamin D repletion may improve CKD-related mortality.7 Environmental influences modify gene and/or receptor expression (gene–environmental) as supported by genetic linkage studies describing susceptibility genes for CKD.41 Increased rates of overexpression of TGF-β1 and/or a higher prevalence of specific TGF-β1 polymorphisms in black individuals may contribute to CKD progression and complications.41a Sickle cell trait (approximately 8% of black individuals), which has traditionally been described as causing renal microinfarction and hyposthenuria42 but not CKD, may in fact be an important unrecognized factor for CKD progression and complications.
Rates of hypertension incidence did not differ among middle-class black and white individuals who had similar levels of baseline BP and body mass index and were followed for 7 yr.43 Racial variation in BP response to antihypertensive therapy has been reported,44 and this could affect disparities in CKD. Sehgal45 assessed overlap between white and black individuals in response to antihypertensive drugs in >12,000 individuals and found that 81 to 95% had similar response for diastolic BP and 83 to 93% for systolic BP, reinforcing heterogeneity within race as much as across race. Gender has been recognized as an important factor in the development of CKD.46 Gender-based genetic variability has been linked to differences in BP in both black47 and white individuals.48 In contrast to testosterone,49,50 estrogens may attenuate CKD progression by lowering the cardiovascular stress response to adrenergic stimuli.51
HEALTH CARE SYSTEMS AND VARIATIONS IN HEALTH OUTCOMES
“You can always count on Americans to do the right thing, after they've tried everything else.”
—Winston Churchill (1874–1965)
Despite the high level of national wealth in the United States, the lack of adequate health insurance for many of the nation's indigent and working middle class is also disproportionately common among racial and ethnic minorities31 and further contributes to the inability of such patients to receive adequate CKD and pre-ESRD care. Several recent studies4,12,13,52,53 but not all54,55 have highlighted racial and ethnic disparities within the health care delivery system, ranging from reduced levels of quality services to poor outcomes. Several of these findings underscore the institutionalization of biases within many health care delivery systems, whereas others point to no insurance, underinsurance, lack of access to quality care, and/or multiple payer or nonuniform systems of care as the major driving forces for disparities in health care outcomes.
Although many studies have demonstrated that improvements in access and standardization of care can reduce disparities in many chronic health conditions, many CKD-related outcomes remain outliers. Examining diabetes-related complications in an ethnically diverse population with standardized health care coverage, Karter et al.55 found similar or reduced rates of complications in minority enrollees in comparison with white enrollees, with the exception of developing ESRD, which was significantly more common across all minority groups compared with white individuals. This unique finding that only CKD outcomes did not improve for minorities when care was standardized suggests that there may be non–health care system factors that are important for kidney-related outcomes and/or that additional novel quality care indicators are important for patients with CKD. ESRD is unique, in that most patients are covered by Medicare, and is generally characterized by equity in access to care,56,57 except awaiting cadaveric-donor renal transplantation, for which standardized health care reduces the black–white difference but significant differences still exist,58 most likely as a result of cultural health beliefs and practices. A recent report by Gao et al.59 of >13,000 beneficiaries receiving care through the Department of Defense, a standardized health care delivery system, found similar rates of provider compliance for black and white patients for stages 3 and 4 CKD targets. Follow-up on ESRD rates will help to provide insights into the effects of quality care on CKD progression across gender and racial/ethnic groups. Despite several study limitations, these findings strongly support the possibility for dramatic attenuation of socioeconomic, gender, and racial/ethnic disparities for patients who have CKD and are treated within a standardized or single-payer health care delivery system.
THE WAY FORWARD: STRATEGIES FOR REDUCING DISPARITIES AND FUTURE RESEARCH DIRECTIONS
“When you have exhausted all possibilities, Remember this…you haven't.”
—Author Unknown
What can or should government, industry, and physicians do to address the racial/ethnic disparities in CKD care? The Department of Health and Human Services has created a strategy for value-driven CKD health care initiatives that includes focusing on health disparities, developing and measuring CKD quality and efficiency metrics at the dialysis facility and nephrologist level, reporting outcomes including consumer/payer choice incentives, reforming reimbursement, supporting interoperable health information technology, and promoting evidence-based care and coordinated care.60
As a medical profession, we too frequently believe that many health issues are beyond our impact, citing them as societal issues, not realizing that we are society,61–63 while our apathy and inaction only perpetuate the current state of affairs. For a moment, let's imagine that we actually embrace the moral imperative of health equity: What might be implemented to improve our understanding and respect of our patients’ diverse cultural values, transform our institutions and social structures to promote health and well-being, and generate the advocacy skills that will be needed to make universal access and quality uniform health care a reality?
Effective Communication
Lack of effective communication, including issues such as limited health literacy, is a pervasive and independent risk factor for poor health outcomes.64,65 A renewed emphasis on current provider education and the education of future generations of providers that might include structured fellowship training for sensitivity to cultural, socioeconomic, and gender diversity; leadership in health promotion and disease prevention; and actionable skill sets to engage in transforming health care systems and advocating for relevant health and health care policies as part of a comprehensive approach to high-quality CKD and ESRD care.66,67 Many of our health messages need to provide effective education for high-risk communities,68,69 such as easily readable and linguistically appropriate CKD-related educational materials70,71 and approaching patient encounters with a presumption of limited health literacy.65 Specific suggestions for improving communication at a health care system level include making cultural competency a core institutional value, ongoing training and evaluation on cultural competency issues, collecting demographic data to allow assessment of potential disparities in quality, collecting data on patients’ primary language to help guide service provision and translation services, and promoting providers and staff diversity in targeted communities and involving consumers and community leaders in the design of local programs and services.68
Medical Advocacy for Improved Health Care Systems
In 2003, a stakeholder group identified 19 key barriers to optimizing CKD care in the United States, such as the lack of adequate reimbursement, difficulty of providing care coordination and nonphysician services, and the lack of availability of both primary care and specialty physicians.72 A more recent series of in-depth discussions with a geographically diverse group of nephrology practices throughout the country identified economic reality/reimbursement and the difficulty in delivering multidisciplinary care as impeding attempts to improve quality for patients with CKD (R. Rettig, PhD, RAND Corporation, Washington, DC, personal communication, January 2008). A collaborative legislative agenda to improve care for patients with CKD developed by the Renal Physicians Association, American Society of Nephrology, National Kidney Foundation, and American Society of Pediatric Nephrology is focusing on appropriate funding for CKD care that is delivered in a CKD clinic or office setting. This agenda includes advocacy for Medicare coverage for educational efforts regarding CKD, including transplantation and dialysis options, as well as increased basic and health services research to advance knowledge about CKD and its treatment (A. Kliger, MD, Yale University School of Medicine, New Haven, CT, personal communication, January 2008). Additional approaches include advocacy for structured coordinated care systems and/or the use of disease management approaches to link economic incentives to improved clinical outcomes. Specific health care system approaches recently proposed by Dr. Jan Blustein include setting achievable performance targets (will help reduce “cherry picking”), providing targeted infusions of expertise or technology and of infrastructure investment in underresourced environments, and supplemental funding to those caring for high volumes of low-revenue patients.20
One approach that has been shown effective in delivering high-quality care for those with chronic disease by integrating many of these strategies is the chronic care model, which fosters productive interactions between informed patients who take an active part in their care and providers with resources and expertise (Figure 4).73,74
Research Approaches to Address Disparities
Dr. Claude Lenfant, former director of the National Institutes of Health National Heart, Lung, and Blood Institute, noted, “Enormous amounts of new knowledge are barreling down the information highway, but they are not arriving at the doorsteps of our patients, especially for a disproportionately high percentage of women, racial and ethnic minorities, and other high-risk groups in the US health care system.”75 He emphasized multidisciplinary or translational research approaches, including rigorous research, to improve health care systems and provider–patient interfaces. For CKD, this translates into research investments in renal biology and pathophysiology in the context of patient- and community-level influences.76 Disparities in CKD have paved a unique roadmap for promising opportunities for research investment, including promising naturally occurring cost-effective interventions such as vitamin D77 or emerging novel peptides such as FT061452, a glutathione precursor with vitamin implications,78 which are more likely to be highly embraced by low-resource and minority communities.
CONCLUSIONS
“The secret of the care of the patient is caring for the patient.”
—Francis Peabody (1881–1927)
Inequities in the incidence, prevalence, and treatment of CKD/ESRD are well documented and vary among different minority groups. Despite the progress made, many of the diverse factors that influence the initiation and progression of CKD and the disparities therein are not fully understood. Although modifiable risk factors, such as culture, socioeconomic status, and access to medical care, contribute to a large proportion of CKD disparities, additional risk factors, from emerging biomarkers to providing structured and coordinated health care delivery, remain to be defined more clearly. To improve the care of diverse communities, medical research alone is insufficient. Efforts to address lingering social injustices that perpetuate limited educational opportunities, socioeconomic imbalances, and limited access to health care are needed to ensure that the contributions of advancing medical care will have a clinically relevant impact on improving patient outcomes (Table 3).
The nephrology community has the opportunity to address not only inequities within health care systems but also many of the sensitive issues that underlie the propagation of community-level health disparities, including elimination of injustices embedded within the social systems that influence health and health care and the promotion and inculcation of community-level and personal responsibility for health- and health care–related behaviors.79–81 In addition, the nephrology community can take a leadership role in a re-conceptualization of the medical community's understanding of health so that our society and health-related systems are focused on well-being and true prevention, not just early detection or reactive acute care. The word “health” is derived from the Anglo-Saxon root “hale,” which means to be whole. Our present focus on medical care and creating a medical care workforce must change to a broader focus on health, enabling us to recapture the true calling of the physician, and the actualization of a vision of insurance, medical, and related systems of “health” care that can provide uniform quality care based on the patient as a human being and truly considering care as holistic.
DISCLOSURES
None.
;)
Figure 1: Differences, disparities, and discrimination. Adapted from reference (
12), with permission.
A framework for environmental health disparities. Reprinted from reference (
23), with permission.
A framework for integrating key sociocultural determinants of CKD. Adapted from reference (
29), with permission.
The chronic care model. Reprinted from reference (
74), with permission.
Recognizing socioeconomic and/or racial/ethnic factors contributing to disparities in health outcomes
Table 2: Socioeconomic class and values of key determinants of healtha
Table 3: CKD: A call to actiona
K.N. is supported in part by the National Center for Research Resources, Research Centers in Minority Institutions (RR14616, RR11145, and RR019234), and the DREW/UCLA Project EXPORT, National Institutes of Health, National Center on Minority Health and Health Disparities (P20-MD00182). A.N. is supported in part by the National Center for Research Resources, Research Centers in Minority Institutions (U54 RR019234), and the Richard Rosenthal Dialysis Fund.
Presented in part as “Race, Gender, and Socioeconomic Disparities in CKD in the United States” at the American Society of Nephrology Symposium for Health Disparities in Nephrology; October 31 through November 5, 2007; San Francisco, CA.
Published online ahead of print. Publication date available at www.jasn.org.
See related editorial, “Is the Ethnic Disparity in CKD a Symptom of Dysfunctional Primary Care in the US?” on pages 1249–1251.
REFERENCES
1. Levey AS, Andreoli SP, DuBose T, Provenzano R, Collins AJ: Chronic kidney disease: Common, harmful, and treatable—World Kidney Day 2007. J Am Soc Nephrol 18: 374–378, 2007
2. Shah SV, Feehally J: The third World Kidney Day: Looking back and thinking forward. Kidney Int 73: 372–374, 2008
3. Coresh J, Selvin E, Stevens LA, Manzi J, Kusek JW, Eggers P, Van Lente F, Levey AS: Prevalence of chronic kidney disease in the United States. JAMA 298: 2038–2047, 2007
4. Kressin NR, Petersen LA: Racial differences in the use of invasive cardiovascular procedures: Review of the literature and prescription for future research. Ann Intern Med 135: 352–366, 2001
5. Schneider EC, Leape LL, Weissman JS, Piana RN, Gatsonis C, Epstein AM: Racial differences in cardiac revascularization rates: Does “overuse” explain higher rates among white patients? Ann Intern Med 135: 328–337, 2001
6. Kalantar-Zadeh K, Block G, Humphreys MH, Kopple JD: Reverse epidemiology of cardiovascular risk factors in maintenance dialysis patients. Kidney Int 63: 793–808, 2003
7. Wolf M, Betancourt J, Chang Y, Shah A, Teng M, Tamez H, Gutierrez O, Camargo CA Jr, Melamed M, Norris K, Stampfer MJ, Powe NR, Thadhani R: Impact of activated vitamin D and race on survival among hemodialysis patients. J Am Soc Nephrol 19: 1379–1388, 2008
8. Hsu CY, Lin F, Vittinghoff E, Shlipak MG: Racial differences in the progression from chronic renal insufficiency to end-stage renal disease in the United States. J Am Soc Nephrol 14: 2902–2907, 2003
9. Mehrotra R, Kermah D, Fried L, Adler S, Norris K: Racial differences in mortality among those with CKD. J Am Soc Nephrol 19: 1403–1410, 2008
10. US Renal Data System: USRDS 2007 Annual Data Report: Atlas of Chronic Kidney Disease and End-Stage Renal Disease in the United States, Bethesda, National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases, 2007
11. Agodoa L, Eggers P: Racial and ethnic disparities in end-stage kidney failure-survival paradoxes in African-Americans. Semin Dial 20: 577–585, 2007
12. Smedley BD, Stith AY, Nelson AR, eds.: Unequal Treatment: Confronting Racial and Ethnic Disparities in Health Care. Washington, DC, National Academy Press, 2003
13. Schulman KA, Berlin JA, Harless W, Kerner JF, Sistrunk S, Gersh BJ, Dubé R, Taleghani CK, Burke JE, Williams S, Eisenberg JM, Escarce JJ: The effect of race and sex on physician's recommendations for cardiac catheterization. N Engl J Med 340: 618–626, 1999
14. Mortality among Negroes in Cities. In: Proceedings of the Conference for Investigation of City Problems. Atlanta University Publications. No. 1, Atlanta, Atlanta University, 1896 . Available at
http://www.library.umass.edu/spcoll/digital/dubois/dubois1.pdf
15. Du Bois WEB: The Philadelphia Negro: A Social Study, Philadelphia, University of Pennsylvania Press, 1899 (reprinted 1996)
16. Smith DB: Racial and ethnic health disparities and the unfinished civil rights agenda. Health Aff (Millwood) 24: 317–324, 2005
17. Powe NR: To have and have not: Health and health care disparities in chronic kidney disease. Kidney Int 64: 763–772, 2003
18. Philbin EF, McCullough PA, DiSalvo TG, Dec GW, Jenkins PL, Weaver WD: Underuse of invasive procedures among Medicaid patients with acute myocardial infarction. Am J Public Health 91: 1082–1088, 2001
19. Jha AK, Varosy PD, Kanaya AM, Hunninghake DB, Hlatky MA, Waters DD, Furberg CD, Shlipak MG: Differences in medical care and disease outcomes among black and white women with heart disease. Circulation 108: 1089–1094, 2003
20. Blustein J: Who is accountable for racial equity in health care? JAMA 299: 814–816, 2008
21. Federal Housing Administration, Underwriting Manual: Underwriting and Valuation Procedure Under Title II of the National Housing Act With Revisions to February, 1938 (Washington, D.C.), Part II, Section 9, Rating of Location. Available at:
http://www.public.asu.edu/∼wplotkin/DeedsWeb/fha38.html. Accessed February 11, 2008
22. Araujo JA, Barajas B, Kleinman M, Wang X, Bennett BJ, Gong KW, Navab M, Harkema J, Sioutas C, Lusis AJ, Nel AE: Ambient particulate pollutants in the ultrafine range promote early atherosclerosis and systemic oxidative stress. Circ Res 102: 589–596, 2008
23. Gee GC, Payne-Sturges DC: Environmental health disparities: A framework integrating psychosocial and environmental concepts. Environ Health Perspect 112: 1645–1653, 2004
24. Volkova N, McClellan W, Klein M, Flanders D, Kleinbaum D, Soucie JM, Presley R: Neighborhood poverty and racial differences in ESRD incidence. J Am Soc Nephrol 19: 356–364, 2008
25. Rodriguez RA, Sen S, Mehta K, Moody-Ayers S, Bacchetti P, O'Hare AM: Geography matters: Relationships among urban residential segregation, dialysis facilities, and patient outcomes. Ann Intern Med 146: 493–501, 2007
26. Nolte E, McKee CM: Measuring the health of nations: Updating an earlier analysis. Health Aff (Millwood) 27: 58–71, 2008
27. Schroeder S: Shattuck Lecture: We can do better: Improving the health of the American people. N Engl J Med 357: 1221–1228, 2007
28. Betancourt JR, Green AR, Carrillo JE: The challenges of cross-cultural healthcare: Diversity, ethics, and the medical encounter. Bioethics Forum 16: 27–32, 2000
29. Norris KC, Agodoa LY: Unraveling the racial disparities associated with kidney disease. Kidney Int 68: 914–924, 2005
30. Betancourt JR: Cultural competence–marginal or mainstream movement? N Engl J Med 351: 953–955, 2004
31. Key Facts: Race, Ethnicity and Medical Care, 2007 Update, The Henry J Kaiser Family Foundation. Available at:
http://www.kff.org/minorityhealth/6069.cfm. Accessed February 12, 2008
32. Martins D, Tareen N, Zadshir A, Pan D, Vargas R, Nissenson A, Norris K: The association of poverty with the prevalence of albuminuria: Data from the Third National Health and Nutrition Examination Survey (NHANES III). Am J Kidney Dis 47: 965–971, 2006
33. Keppel KG, Pearcy JN, Wagener DK: Trends in racial and ethnic-specific rates for the health status indicators: United States, 1990–98. Healthy People 2000 Stat Notes 23: 1–16, 2002
34. Duru OK, Vargas RB, Kermah D, Pan D, Norris KC: Health insurance status and hypertension monitoring and control in the United States. Am J Hypertens 20: 348–353, 2007 Apr
35. Li S, Chen SC, Shlipak M, Bakris G, McCullough PA, Sowers J, Stevens L, Jurkovitz C, McFarlane S, Norris K, Vassalotti J, Klag MJ, Brown WW, Narva A, Calhoun D, Johnson B, Obialo C, Whaley-Connell A, Becker B, Collins AJ: Low birth weight is associated with chronic kidney disease only in men. Kidney Int 73: 637–642, 2008
36. Duru OK, Jurkovitz C, Narva A, McGill J, Bakris G, Chen S-C, Li S, Pergola P, McCullough P, Singh A, Klag M, Collins A, Brown W, Norris K: Racial and gender differences in hypertension control in chronic kidney disease: Results from the Kidney Early Evaluation Program (KEEP). Am J Kidney Dis 51: 192–198, 2008
37. Cann HM: Human genome diversity. C R Acad Sci III 321: 443–446, 1998
38. Sankar P, Cho MK, Condit CM, Hunt LM, Koenig B, Marshall P, Lee SS, Spicer P: Genetic research and health disparities. JAMA 291: 2985–2989, 2004
39. Martins D, Wolf M, Pan Deyu, Zadshir A, Tareen N, Thadhani R, Felsenfeld A, Levine B, Mehrotra R, Norris K: The Prevalence of cardiovascular risk factors and the serum levels of vitamin D in the United States: Data from the NHANES III. Arch Intern Med 167: 1159–1165, 2007
40. Wu-Wong JR, Nakane M, Ma J: Vitamin D analogs modulate the expression of plasminogen activator inhibitor-1, thrombospondin-1 and thrombomodulin in human aortic smooth muscle cells. J Vasc Res 44: 11–18, 2007
41. Freedman BI: Susceptibility genes for hypertension and renal failure. J Am Soc Nephrol 14 [Suppl 2]: S192–S194, 2003
41a. Suthanthiran M, Li B, Song JO, Ding R, Sharma VK, Schwartz JE, August P: Transforming growth factor-beta 1 hyperexpression in African-American hypertensives: A novel mediator of hypertension and/or target organ damage. Proc Natl Acad Sci USA 97: 3479–3484, 2000
42. Schlitt L, Keitel HG: Pathogenesis of hyposthenuria in persons with sickle cell anemia or the sickle cell trait. Pediatrics 26: 249–254, 1960
43. He J, Klag MJ, Appel LJ, Charleston J, Whelton PK: Seven-year incidence of hypertension in a cohort of middle-aged African Americans and whites. Hypertension 31: 1130–1135, 1998
44. Materson BJ, Reda DJ, Cushman WC, Massie BM, Freis ED, Kochar MS, Hamburger RJ, Fye C, Lakshman R, Gottdiener J, Eli A. Ramirez, William G. Henderson, for the Department of Veterans Affairs Cooperative Study Group on Antihypertensive Agents: Single-drug therapy for hypertension in men: A comparison of six antihypertensive agents with placebo. The Department of Veterans Affairs Cooperative Study Group on Antihypertensive Agents. N Engl J Med 328: 914–921, 1993 [erratum appears in N Engl J Med 330: 1689, 1994]
45. Sehgal AR: Overlap between whites and blacks in response to antihypertensive drugs. Hypertension 43: 566–572, 2004
46. Silbiger SR, Neugarten J: The impact of gender on the progression of chronic renal disease. Am J Kidney Dis 25: 515–533, 1995
47. Wang JG, Staessen JA: Genetic polymorphisms in the renin-angiotensin system: Relevance for susceptibility to cardiovascular disease. Eur J Pharmacol 410: 289–302, 2000
48. Rana BK, Insel PA, Payne SH, Abel K, Beutler E, Ziegler MG, Schork NJ, O'Connor DT: Population-based sample reveals gene-sex interactions in blood pressure in white Americans. Hypertension 49: 96–106, 2007
49. Khalil RA: Sex hormones as potential modulators of vascular function in hypertension. Hypertension 46: 249–254, 2005
50. Reyes D, Lew SQ, Kimmel PL: Sex differences in hypertension and kidney disease. Med Clin North Am 89: 613–630, 2005
51. August P, Oparil S: Hypertension in women. J Clin Endocrinol Metab 84: 1862–1866, 1999
52. Lavery LA, Van Houtum WH, Ashry HR, Armstrong DG, Pugh JA: Diabetes-related lower-extremity amputations disproportionately affect blacks and Mexican Americans. South Med J 92: 593–599, 1999
53. Schneider EC, Cleary PD, Zaslavsky AM, Epstein AM: Racial disparity in influenza vaccination: Does managed care narrow the gap between African Americans and whites? JAMA 286: 1455–1460, 2001
54. Maynard C, Wright SM, Every NR, Ritchie JL: Racial differences in outcomes of veterans undergoing percutaneous coronary interventions. Am Heart J 142: 309–313, 2001
55. Karter AJ, Ferrara A, Liu JY, Moffet HH, Ackerson LM, Selby JV: Ethnic disparities in diabetic complications in an insured population. JAMA 287: 2519–2527, 2002 [erratum appears in JAMA 288: 46, 2002]
56. Daumit GL, Hermann JA, Coresh J, Powe NR: Use of cardiovascular procedure among black persons and white persons: A 7-year nationwide study in patients with renal disease. Ann Intern Med 130: 173–182, 1999
57. Daumit GL, Hermann JA, Powe NR: Relation of gender and health insurance to cardiovascular procedure use in persons with progression of chronic renal disease. Med Care 38: 354–635, 2000
58. Keith D, Ashby VB, Port FK, Leichtman AB: Insurance type and minority status associated with large disparities in prelisting dialysis among candidates for kidney transplantation. Clin J Am Soc Nephrol 3: 463–470, 2008
59. Gao SW, Oliver DK, Das N, Hurst FP, Lentine KL, Agodoa LY, Abbott KC: Assessment of racial disparities in chronic kidney disease stage 3 and 4 care in the Department of Defense health system. Clin J Am Soc Nephrol 3: 442–449, 2008
60. Straube BM: The imperatives for change in the US health care payment and delivery systems are clear. Adv Chronic Kidney Dis 15: 7–9, 2008
61. Krishnamurti J: Meeting Life: Writings and Talks on Finding Your Path Without Retreating from Society, San Francisco, HarperOne, 1991, pp 17–19
62. Krishnamurti J: The Awakening of Intelligence, San Francisco, HarperOne, 1987, pp 15–89
63. Bohm D: Wholeness and the Implicate Order, London, Routledge, 1998, pp 1–26
64. Persell SD, Osborn CY, Richard R, Skripkauskas S, Wolf MS: Limited health literacy is a barrier to medication reconciliation in ambulatory care. J Gen Intern Med 22: 1523–1526, 2007
65. Volandes AE, Paasche-Orlow MK: Health literacy, health inequality and a just healthcare system. Am J Bioeth 7: 5–10, 2007
66. Horner RD, Salazar W, Geiger HJ, Bullock K, Corbie-Smith G, Cornog M, Flores G, Working Group on Changing Health Care Professionals’ Behavior: Changing healthcare professionals’ behaviors to eliminate disparities in healthcare: What do we know? How might we proceed? Am J Manag Care 10 (Spec No.): SP12–SP19, 2004
67. Nissenson AR, Agarwal R, Allon M, Cheung AK, Clark W, Depner T, Diaz-Buxo JA, Kjellstrand C, Kliger A, Martin KJ, Norris K, Ward R, Wish J: Improving outcomes in CKD and ESRD patients: Carrying the torch from training to practice. Semin Dial 17: 380–397, 2004
68. Taylor SL, Lurie N: The role of culturally competent communication in reducing ethnic and racial healthcare disparities. Am J Manag Care 10 (Spec No): SP1–SP4, 2004
69. Calderón JL, Beltrán RA: Pitfalls in health communication: Healthcare policy, institution, structure, and process. Med Gen Med 6: 9, 2004
70. Calderón JL, Zadshir A, Norris K: A survey of kidney disease and risk-factor information on the World Wide Web. Med Gen Med 6: 3, 2004
71. Irvine FE, Roberts GW, Jones P, Spencer LH, Baker CR, Williams C: Communicative sensitivity in the bilingual healthcare setting: A qualitative study of language awareness. J Adv Nurs 53: 422–434, 2006
72. Parker TF, Blantz R, Hostetter T, Himmelfarb J, Kliger A, Lazarus M, Nissenson AR, Pereira B, Weiss J: The chronic kidney disease initiative. J Am Soc Nephrol 15: 708–716, 2004
73. Wagner EH: Chronic disease management: What will it take to improve care for chronic illness? Eff Clin Pract 1: 2–4, 1998
75. Lenfant C: Clinical research to clinical practice: Lost in translation? N Engl J Med 349: 868–874, 2003
76. Powe NR: Reverse race and ethnic disparities in survival increase with severity of chronic kidney disease: What does this mean? Clin J Am Soc Nephrol 1: 905–906, 2006
77. Holick MF: Vitamin D deficiency. N Engl J Med 357: 266–281, 2007
78. Sinha-Hikim I, Shen R, Lee P, Crum A, Norris K: Evaluation of Glutathione Precursors in Modifying Metabolic and Cellular Response to Increased Oxidative Stress. American Federation for Medical Research 2008 Western Regional Meeting; January 30 through February 2, 2008; Carmel, CA
79. Exworthy M, Washington AE: Organizational strategies to tackle health-care disparities in the USA. Health Serv Manage Res 19: 44–51, 2006
80. Norris K, Nissenson AR: Racial disparities in chronic kidney disease: Tragedy, opportunity, or both? Clin J Am Soc Nephrol 3: 314–316, 2008
81. Nilsen ES, Myrhaug HT, Johansen M, Oliver S, Oxman AD: Methods of consumer involvement in developing healthcare policy and research, clinical practice guidelines and patient information material. Cochrane Database Syst Rev 3: CD004563, 2006
82. Henry BR, Houston S, Mooney GH: Institutional racism in Australian healthcare: A plea for decency. Med J Aust 180: 517–520, 2004
83. Griffith DM, Mason M, Yonas M, Eng E, Jeffries V, Plihcik S, Parks B: Dismantling institutional racism: Theory and action. Am J Community Psychol 39: 381–392, 2007
84. Burnes Bolton L, Giger JN, Georges CA: Structural and racial barriers to health care. Annu Rev Nurs Res 22: 39–58, 2004
85. Krieger N, Rowley DL, Herman AA, Avery B, Phillips MT: Racism, sexism, and social class: Implications for studies of health, disease, and well-being. Am J Prev Med 9: 82–122, 1993
86. Williams DR, Collins C: Racial residential segregation: A fundamental cause of racial disparities in health. Public Health Rep 116: 404–416, 2001
87. Gary TL, Safford MM, Gerzoff RB, Ettner SL, Karter AJ, Beckles GL, Brown AF: Perception of neighborhood problems, health behaviors, and diabetes outcomes among adults with diabetes in managed care: The Translating Research Into Action for Diabetes (TRIAD) study. Diabetes Care 31: 273–278, 2008
88. Morenoff JD, House JS, Hansen BB, Williams DR, Kaplan GA, Hunte HE: Understanding social disparities in hypertension prevalence, awareness, treatment, and control: The role of neighborhood context. Soc Sci Med 65: 1853–1866, 2007
89. Murray CJ, Kulkarni SC, Michaud C, Tomijima N, Bulzacchelli MT, Iandiorio TJ, Ezzati M: Eight Americas: Investigating mortality disparities across races, counties, and race-counties in the United States. PLoS Med 3: e260, 2006
90. Nichols EJ: Introduction to the Axiological Model. Paper Presented at the World Psychiatric Association and the Nigerian Association of Psychiatrists, University of Ibadan; July 1976; Ibadan, Nigeria
91. The L.A. Workforce Literacy Project, 2004 . Available at:
http://www.unitedwayla.com/pages/rpts_resource/literacyatworkexecsum.pdf. Accessed January 27, 2008
92. Yeo S: Language barriers and access to care. Annu Rev Nurs Res 22: 59–73, 2004
93. Kifano S, Smith E: Ebonics and education in the context of culture: Meeting the language and cultural needs of LEP African American students. In: Ebonics: The Urban Education Debate (New Perspectives on Language and Education), 2nd Ed., edited by Ramirez JD, Wiley TG, de Klerk G, Lee E, Wright WE, Tonawanda, NY, Multilingual Matters Limited, 2005, pp 62–95
94. Smith EA: The Historical Development of African American Language, Los Angeles, Watts College Press, 1994
95. Payne RK: Framework for Understanding Poverty, Highlands, TX, Aha Process Inc., 2003
96. Nicholas S, Agodoa LY, Norris K: Ethnic disparities in the prevalence and treatment of kidney disease. Nephrol News Issues 18: 29–30, 32, 34 passim, 2004
