Trends in Racial Disparities in Care
http://www.100md.com
《新英格兰医药杂志》
To the Editor: The Special Articles by Jha et al.,1 Vaccarino et al.,2 and Trivedi et al.3 (Aug. 18 issue) generate serious misconceptions. Reducing the disparity in health outcomes between black patients and white patients is very important. The approach that will substantially reduce racial disparities in health is a reduction in the prevalence and improved treatment of key risk factors,4 especially elevated blood pressure, diabetes, obesity, and cigarette smoking. Blacks and whites with low levels of cardiovascular risk factors have extremely low rates of death from cardiovascular disease and low total mortality.5 There has been a very substantial decline in total mortality from cardiovascular disease and stroke. The decline per year is similar for blacks and whites.6 This decline is due to effective therapies for lowering blood pressure and lipid levels and a decline in cigarette smoking. We continue to spend far too much money focusing on tertiary expensive care and little on underfunded public health initiatives and preventive-medicine approaches to reducing disparities in the United States. The extremely high prevalence of hypertension among blacks and the poor control of blood pressure7 contribute to a higher risk of cardiovascular disease, dementia, disability, and death.8 The use of polio vaccination is far better than improvements in the distribution of ventilators.
Lewis H. Kuller, M.D., Dr.P.H.
University of Pittsburgh
Pittsburgh, PA 15213
kullerl@edc.pitt.edu
References
Jha AK, Fisher ES, Li Z, Orav EJ, Epstein AM. Racial trends in the use of major procedures among the elderly. N Engl J Med 2005;353:683-691.
Vaccarino V, Rathore SS, Wenger NK, et al. Sex and racial differences in the management of acute myocardial infarction, 1994 through 2002. N Engl J Med 2005;353:671-682.
Trivedi AN, Zaslavsky AM, Schneider EC, Ayanian JZ. Trends in the quality of care and racial disparities in Medicare managed care. N Engl J Med 2005;353:692-700.
Thomas AJ, Eberly LE, Davey Smith G, Neaton JD, Stamler J. Race/ethnicity, income, major risk factors, and cardiovascular disease mortality. Am J Public Health 2005;95:1417-1423.
Stamler J, Neaton JD, Garside DB, Daviglus ML. Current status: six established major risk factors and low risk. In: Marmot M, Elliott P, eds. Coronary heart disease epidemiology: from aetiology to public health. 2nd ed. Oxford, England: Oxford University Press, 2005:32-70.
Leupker RV. US trends. In: Marmot M, Elliott P, eds. Coronary heart disease epidemiology: from aetiology to public health. 2nd ed. Oxford, England: Oxford University Press, 2005:73-82.
Kramer H, Han C, Post W, et al. Racial/ethnic differences in hypertension and hypertension treatment and control in the Multi-Ethnic Study of Atherosclerosis (MESA). Am J Hypertens 2004;17:963-970.
Krop JS, Coresh J, Chambless LE, et al. A community-based study of explanatory factors for the excess risk for early renal function decline in blacks vs whites with diabetes: the Atherosclerosis Risk in Communities Study. Arch Intern Med 1999;159:1777-1783.
To the Editor: Vaccarino et al. report that differences according to sex and race in the management of acute myocardial infarction have not narrowed over the past decade and that "some unmeasured characteristic of patients or a health care factor" may explain these differences. Environmental factors, including inferior access to or inadequate delivery of medical care, or both, for blacks and women clearly contribute. However, the markedly lower amounts of calcified coronary plaque among black patients, despite poorer control of conventional risk factors for cardiovascular disease,1,2 the significantly lower black:white ratio of rates of cardiovascular disease given equivalent access to health care,3,4 and the presence of biologic differences in susceptibility to cardiovascular disease between races and sexes are probably the "unmeasured" characteristics referred to by the authors. Racial and sex disparities in access to good-quality health care and improved socioeconomic status urgently need to be addressed. A balanced discussion of racial and sex differences in susceptibility to cardiovascular disease that are potentially due to biologic factors, as well as the role of these factors in health care delivery, should also be addressed in studies of this type.
Barry I. Freedman, M.D.
Lynne E. Wagenknecht, Dr.P.H.
Donald W. Bowden, Ph.D.
Wake Forest University School of Medicine
Winston-Salem, NC 27157
bfreedma@wfubmc.edu
References
Freedman BI, Hsu FC, Langefeld CD, et al. The impact of ethnicity and gender on subclinical cardiovascular disease: the Diabetes Heart Study. Diabetologia (in press).
Bild DE, Detrano R, Peterson D, et al. Ethnic differences in coronary calcification: the Multi-Ethnic Study of Atherosclerosis (MESA). Circulation 2005;111:1313-1320.
Karter AJ, Ferrara A, Liu JY, Moffet HH, Ackerson LM, Selby JV. Ethnic disparities in diabetic complications in an insured population. JAMA 2002;287:2519-2527.
Young BA, Maynard C, Boyko EJ. Racial differences in diabetic nephropathy, cardiovascular disease, and mortality in a national population of veterans. Diabetes Care 2003;26:2392-2399.
To the Editor: Trivedi and colleagues observe that absolute disparities between black Medicare enrollees and white enrollees declined for seven of nine measures of health care. Conclusions about changes in disparities over time depend on whether the disparities are measured in absolute or relative terms and whether the measures are expressed in terms of favorable or adverse events.1,2,3 In Healthy People 2010, all dichotomous measures are expressed in terms of adverse events, and reductions in relative disparities are required to demonstrate progress toward the goal of eliminating disparities.4 When the data in Table 3 in the article by Trivedi et al. are analyzed in this way, reductions in absolute disparities for four measures become relative increases and small increases for two measures become substantial relative increases (Table 1). Although there may be sound policy reasons or management reasons for presenting data on disparities with the use of other methods, greater consistency is needed in what we mean when we say that disparities are being reduced.
Table 1. Reanalysis of Adherence to HEDIS Measures of Quality of Care According to Adverse Events and a Relative Measure of Disparity.
Kenneth G. Keppel, Ph.D.
Jeffrey N. Pearcy, M.S.
Centers for Disease Control and Prevention
Hyattsville, MD 20782
kkeppel@cdc.gov
Joel S. Weissman, Ph.D.
Harvard Medical School
Boston, MA 02115
References
Anand S, Diderichsen F, Evans T, Shkolnikov VM, Wirth M. Measuring disparities in health: methods and indicators. In: Evans T, Whitehead M, Diderichsen F, Bhuiya A, Wirth M, eds. Challenging inequalities in health: from ethics to action. Oxford, England: Oxford University Press, 2001:48-65.
Keppel KG, Pamuk E, Lynch J, et al. Methodological issues in measuring health disparities. Vital and health statistics. Series 2. No. 141. Washington, D.C.: Government Printing Office, 2005. (DHHS publication no. (PHS) 2005-1341.)
Keppel KG, Pearcy JN. Measuring relative disparities in terms of adverse outcomes. J Public Health Manag Pract (in press).
Keppel KG, Pearcy JN, Klein RJ. Measuring progress in Healthy People 2010. Healthy People statistical notes. No. 25. Hyattsville, Md.: National Center for Health Statistics, September 2004. (DHHS publication no. (PHS) 2004-1237.)
Trivedi AN, Zaslavsky AM, Schneider EC, Ayanian JZ. Trends in the quality of care and racial disparities in Medicare managed care. N Engl J Med 2005;353:692-700.
To the Editor: Jha et al. highlight the persistent racial differences in the use of nine major procedures from 1992 through 2001. They note increasing disparity in the rate of carotid endarterectomy since 1992. They note an increase in the rate of carotid endarterectomy in all groups analyzed according to sex and race, with the rate of increase being lower among black patients. This difference was also found in the majority of hospital-referral regions.
The authors speculate that the discrepancy could reflect the adoption of more aggressive surgical treatment methods by white patients and their physicians after the recent publication of expanded indications for carotid endarterectomy.1,2 However, we feel that this difference could be attributed to a lower prevalence of extracranial carotid-artery stenosis among blacks.3,4,5 The lower prevalence of extracranial stenosis and the higher prevalence of intracranial disease among blacks have been noted in arteriographic and ultrasonographic studies. This difference might account for the lower rates of carotid endarterectomy among black patients.
Basil E. Akpunonu, M.D.
Anand B. Mutgi, M.D.
Sadik A. Khuder, Ph.D.
Medical University of Ohio at Toledo
Toledo, OH 43614
bakpunonu@meduohio.edu
References
North American Symptomatic Carotid Endarterectomy Trial Collaborators. Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis. N Engl J Med 1991;325:445-453.
European Carotid Surgery Trialists' Collaborative Group. MRC European Carotid Surgery Trial: interim results for symptomatic patients with severe (70-99%) or with mild (0-29%) carotid stenosis. Lancet 1991;337:1235-1243.
Solberg LA, McGarry PA. Cerebral atherosclerosis in Negroes and Caucasians. Atherosclerosis 1972;16:141-154.
Gil-Peralta A, Alter M, Lai SM, et al. Duplex Doppler and spectral flow analysis of racial differences in cerebrovascular atherosclerosis. Stroke 1990;21:740-744.
Heyman A, Fields WS, Keating RD. Joint study of extracranial arterial occlusion. VI. Racial differences in hospitalized patients with ischemic stroke. JAMA 1972;222:285-289.
Dr. Vaccarino replies: We agree with Dr. Kuller that primary prevention of cardiovascular disease, focused on reducing risk factors, in particular hypertension and diabetes, is crucial for reducing disparities in outcomes related to cardiovascular disease between blacks and whites. However, our study was focused on treatment differences in a sample of patients with acute myocardial infarction. It was not our objective to examine overall causes of race-related health disparities in cardiovascular disease. Treating and controlling risk factors in black patients, as in white patients, to prevent cardiovascular disease are clearly important; however, also important is equity in treatment of persons with established cardiovascular disease.1 To address this question better, we focused on management strategies that have demonstrated efficacy in improving prognosis in this patient population.2 Our research question is not in contraposition to a primary-prevention approach to reducing disparities; it is a different area of investigation.
Dr. Freedman and coworkers argue that differences in susceptibility to or severity of cardiovascular disease according to race, as shown by a lower prevalence of calcified plaques and a lower rate of cardiovascular disease among blacks, as compared with whites, probably play a role in explaining differences in the management of acute myocardial infarction. Although these differences may explain differences in the susceptibility to acute coronary events, they should not influence the management of the disease in patients who have a clinically confirmed acute myocardial infarction. Whether a smaller proportion of black patients than white patients in the general population have calcified lesions is immaterial to whether blacks with an acute myocardial infarction should receive guideline-recommended treatment, such as reperfusion therapy. Future research is needed to improve our understanding of processes underlying persistent racial variation in the treatment of patients hospitalized for acute myocardial infarction.
Viola Vaccarino, M.D., Ph.D.
Emory University School of Medicine
Atlanta, GA 30306
viola.vaccarino@emory.edu
for the National Registry of Myocardial Infarction Investigators
References
Smedley BD, Stith AY, Nelson AR, eds. Unequal treatment: confronting racial and ethnic disparities in health care. Washington, D.C.: National Academy Press, 2003.
Ryan TJ, Antman EM, Brooks NH, et al. 1999 Update: ACC/AHA guidelines for the management of patients with acute myocardial infarction: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Management of Acute Myocardial Infarction). J Am Coll Cardiol 1999;34:890-911.
Dr. Jha and colleagues reply: We agree with Dr. Kuller that the reduction of key risk factors for cardiovascular disease is important in improving health outcomes for white and black Americans, and some studies suggest that there may not be large differences in this area.1 Furthermore, we certainly sympathize with the notion that the United States often fails to spend enough resources on simple public health measures that can have a large impact on people's lives. However, such efforts to fund public health initiatives adequately should not prevent us from ensuring that both white and black Americans have access to tertiary care such as coronary-artery bypass graft surgery and total hip replacement. These procedures, when used appropriately, have a profound effect on people's lives and well-being, and black Americans should benefit from them as much as white Americans do.
We appreciate the point raised by Dr. Akpunonu and colleagues that differences in disease prevalence may account for some of the differences in rates of carotid endarterectomy between whites and blacks. Although blacks have much higher rates of stroke,2 there are data suggesting that part of the increase may be due to higher rates of intracranial carotid disease,3 which would not be amenable to surgical repair. However, an examination of more recent data suggests that there may not be substantial racial differences in the rates of extracranial carotid disease. The Northern Manhattan Stroke Study found similar rates of extracranial carotid disease among whites and blacks,4 and another population-based study found higher rates of large-vessel disease among blacks than among whites.5 Most of the other studies that report on racial differences in intracranial and extracranial carotid disease are limited by not being population based and are often dependent on who is referred for imaging of these vessels.
Therefore, although there might be moderate racial differences in extracranial disease, these differences are unlikely to explain the large racial differences in the rates of carotid surgery. Furthermore, they would certainly not explain the dramatic widening of the gap between whites and blacks in the mid-1990s after the release of results of clinical trials that expanded the indications for these procedures.
Ashish K. Jha, M.D., M.P.H.
Arnold M. Epstein, M.D.
Harvard School of Public Health
Boston, MA 02115
E. John Orav, Ph.D.
Brigham and Women's Hospital
Boston, MA 02115
References
Ma J, Stafford RS. Quality of US outpatient care: temporal changes and racial/ethnic disparities. Arch Intern Med 2005;165:1354-1361.
Kissela B, Schneider A, Kleindorfer D, et al. Stroke in a biracial population: the excess burden of stroke among blacks. Stroke 2004;35:426-431.
Inzitari D, Hachinski VC, Taylor DW, Barnett HJ. Racial differences in the anterior circulation in cerebrovascular disease: how much can be explained by risk factors? Arch Neurol 1990;47:1080-1084.
Sacco RL, Kargman DE, Gu Q, Zamanillo MC. Race-ethnicity and determinants of intracranial atherosclerotic cerebral infarction: the Northern Manhattan Stroke Study. Stroke 1995;26:14-20.
Schneider AT, Kissela B, Woo D, et al. Ischemic stroke subtypes: a population-based study of incidence rates among blacks and whites. Stroke 2004;35:1552-1556.
Dr. Trivedi and colleagues reply: We agree with Dr. Kuller about the importance of reducing racial disparities in the prevention, detection, and treatment of major risk factors and chronic conditions. Indeed, the Health Plan Employer Data and Information Set (HEDIS) measures we studied assess primary and secondary preventive services with substantial health benefits for common medical conditions.1
Dr. Keppel and colleagues raise an important issue about how best to quantify and report disparities over time. Although changes in absolute and relative differences may yield different interpretations in some instances, we would not recommend a single approach to reporting disparities for all measures of health outcomes and utilization.
In our analysis of temporal trends in the HEDIS quality-of-care measures, we chose to report absolute disparities, for several reasons. Most important, absolute differences measure the percentage of eligible health-plan enrollees from the underserved groups who would benefit from the elimination of a disparity, so such measures may be more useful to clinicians and health care managers establishing priorities and programs to improve health care. Second, trends in absolute disparities have a consistent interpretation, regardless of whether the principal outcome is specified as receipt or nonreceipt of a measure. In Table 1 in our article, which Dr. Keppel et al. adapted in their letter, the relative racial disparity in nonreceipt of low-density lipoprotein cholesterol testing among enrollees with cardiovascular disease increased over time, whereas the relative disparity would be decreased if defined as receipt of this test.
Furthermore, changes in absolute and relative disparities may have sharply divergent policy implications depending on the proportions being compared. In particular, relative disparities are greatly magnified when adherence (or nonadherence) approaches 0 or 100 percent. Consider, for example, hypothetical decreases in absolute nonadherence from 90 percent to 2 percent among blacks and from 60 percent to 1 percent among whites. Such changes would represent a substantial decrease in absolute disparity from 30 percent to 1 percent but a paradoxical increase in the corresponding relative disparity from 1.5 to 2.0.
For these reasons, rather than adopt a uniform method of reporting, the decision to report absolute disparities, relative disparities, or both should depend on the purpose of the analysis and the reasoned judgment of the investigators.
Amal N. Trivedi, M.D., M.P.H.
Alan M. Zaslavsky, Ph.D.
John Z. Ayanian, M.D., M.P.P.
Harvard Medical School
Boston, MA 02115
References
Neumann PJ, Levine BS. Do HEDIS measures reflect cost-effective practices? Am J Prev Med 2002;23:276-289.
Lewis H. Kuller, M.D., Dr.P.H.
University of Pittsburgh
Pittsburgh, PA 15213
kullerl@edc.pitt.edu
References
Jha AK, Fisher ES, Li Z, Orav EJ, Epstein AM. Racial trends in the use of major procedures among the elderly. N Engl J Med 2005;353:683-691.
Vaccarino V, Rathore SS, Wenger NK, et al. Sex and racial differences in the management of acute myocardial infarction, 1994 through 2002. N Engl J Med 2005;353:671-682.
Trivedi AN, Zaslavsky AM, Schneider EC, Ayanian JZ. Trends in the quality of care and racial disparities in Medicare managed care. N Engl J Med 2005;353:692-700.
Thomas AJ, Eberly LE, Davey Smith G, Neaton JD, Stamler J. Race/ethnicity, income, major risk factors, and cardiovascular disease mortality. Am J Public Health 2005;95:1417-1423.
Stamler J, Neaton JD, Garside DB, Daviglus ML. Current status: six established major risk factors and low risk. In: Marmot M, Elliott P, eds. Coronary heart disease epidemiology: from aetiology to public health. 2nd ed. Oxford, England: Oxford University Press, 2005:32-70.
Leupker RV. US trends. In: Marmot M, Elliott P, eds. Coronary heart disease epidemiology: from aetiology to public health. 2nd ed. Oxford, England: Oxford University Press, 2005:73-82.
Kramer H, Han C, Post W, et al. Racial/ethnic differences in hypertension and hypertension treatment and control in the Multi-Ethnic Study of Atherosclerosis (MESA). Am J Hypertens 2004;17:963-970.
Krop JS, Coresh J, Chambless LE, et al. A community-based study of explanatory factors for the excess risk for early renal function decline in blacks vs whites with diabetes: the Atherosclerosis Risk in Communities Study. Arch Intern Med 1999;159:1777-1783.
To the Editor: Vaccarino et al. report that differences according to sex and race in the management of acute myocardial infarction have not narrowed over the past decade and that "some unmeasured characteristic of patients or a health care factor" may explain these differences. Environmental factors, including inferior access to or inadequate delivery of medical care, or both, for blacks and women clearly contribute. However, the markedly lower amounts of calcified coronary plaque among black patients, despite poorer control of conventional risk factors for cardiovascular disease,1,2 the significantly lower black:white ratio of rates of cardiovascular disease given equivalent access to health care,3,4 and the presence of biologic differences in susceptibility to cardiovascular disease between races and sexes are probably the "unmeasured" characteristics referred to by the authors. Racial and sex disparities in access to good-quality health care and improved socioeconomic status urgently need to be addressed. A balanced discussion of racial and sex differences in susceptibility to cardiovascular disease that are potentially due to biologic factors, as well as the role of these factors in health care delivery, should also be addressed in studies of this type.
Barry I. Freedman, M.D.
Lynne E. Wagenknecht, Dr.P.H.
Donald W. Bowden, Ph.D.
Wake Forest University School of Medicine
Winston-Salem, NC 27157
bfreedma@wfubmc.edu
References
Freedman BI, Hsu FC, Langefeld CD, et al. The impact of ethnicity and gender on subclinical cardiovascular disease: the Diabetes Heart Study. Diabetologia (in press).
Bild DE, Detrano R, Peterson D, et al. Ethnic differences in coronary calcification: the Multi-Ethnic Study of Atherosclerosis (MESA). Circulation 2005;111:1313-1320.
Karter AJ, Ferrara A, Liu JY, Moffet HH, Ackerson LM, Selby JV. Ethnic disparities in diabetic complications in an insured population. JAMA 2002;287:2519-2527.
Young BA, Maynard C, Boyko EJ. Racial differences in diabetic nephropathy, cardiovascular disease, and mortality in a national population of veterans. Diabetes Care 2003;26:2392-2399.
To the Editor: Trivedi and colleagues observe that absolute disparities between black Medicare enrollees and white enrollees declined for seven of nine measures of health care. Conclusions about changes in disparities over time depend on whether the disparities are measured in absolute or relative terms and whether the measures are expressed in terms of favorable or adverse events.1,2,3 In Healthy People 2010, all dichotomous measures are expressed in terms of adverse events, and reductions in relative disparities are required to demonstrate progress toward the goal of eliminating disparities.4 When the data in Table 3 in the article by Trivedi et al. are analyzed in this way, reductions in absolute disparities for four measures become relative increases and small increases for two measures become substantial relative increases (Table 1). Although there may be sound policy reasons or management reasons for presenting data on disparities with the use of other methods, greater consistency is needed in what we mean when we say that disparities are being reduced.
Table 1. Reanalysis of Adherence to HEDIS Measures of Quality of Care According to Adverse Events and a Relative Measure of Disparity.
Kenneth G. Keppel, Ph.D.
Jeffrey N. Pearcy, M.S.
Centers for Disease Control and Prevention
Hyattsville, MD 20782
kkeppel@cdc.gov
Joel S. Weissman, Ph.D.
Harvard Medical School
Boston, MA 02115
References
Anand S, Diderichsen F, Evans T, Shkolnikov VM, Wirth M. Measuring disparities in health: methods and indicators. In: Evans T, Whitehead M, Diderichsen F, Bhuiya A, Wirth M, eds. Challenging inequalities in health: from ethics to action. Oxford, England: Oxford University Press, 2001:48-65.
Keppel KG, Pamuk E, Lynch J, et al. Methodological issues in measuring health disparities. Vital and health statistics. Series 2. No. 141. Washington, D.C.: Government Printing Office, 2005. (DHHS publication no. (PHS) 2005-1341.)
Keppel KG, Pearcy JN. Measuring relative disparities in terms of adverse outcomes. J Public Health Manag Pract (in press).
Keppel KG, Pearcy JN, Klein RJ. Measuring progress in Healthy People 2010. Healthy People statistical notes. No. 25. Hyattsville, Md.: National Center for Health Statistics, September 2004. (DHHS publication no. (PHS) 2004-1237.)
Trivedi AN, Zaslavsky AM, Schneider EC, Ayanian JZ. Trends in the quality of care and racial disparities in Medicare managed care. N Engl J Med 2005;353:692-700.
To the Editor: Jha et al. highlight the persistent racial differences in the use of nine major procedures from 1992 through 2001. They note increasing disparity in the rate of carotid endarterectomy since 1992. They note an increase in the rate of carotid endarterectomy in all groups analyzed according to sex and race, with the rate of increase being lower among black patients. This difference was also found in the majority of hospital-referral regions.
The authors speculate that the discrepancy could reflect the adoption of more aggressive surgical treatment methods by white patients and their physicians after the recent publication of expanded indications for carotid endarterectomy.1,2 However, we feel that this difference could be attributed to a lower prevalence of extracranial carotid-artery stenosis among blacks.3,4,5 The lower prevalence of extracranial stenosis and the higher prevalence of intracranial disease among blacks have been noted in arteriographic and ultrasonographic studies. This difference might account for the lower rates of carotid endarterectomy among black patients.
Basil E. Akpunonu, M.D.
Anand B. Mutgi, M.D.
Sadik A. Khuder, Ph.D.
Medical University of Ohio at Toledo
Toledo, OH 43614
bakpunonu@meduohio.edu
References
North American Symptomatic Carotid Endarterectomy Trial Collaborators. Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis. N Engl J Med 1991;325:445-453.
European Carotid Surgery Trialists' Collaborative Group. MRC European Carotid Surgery Trial: interim results for symptomatic patients with severe (70-99%) or with mild (0-29%) carotid stenosis. Lancet 1991;337:1235-1243.
Solberg LA, McGarry PA. Cerebral atherosclerosis in Negroes and Caucasians. Atherosclerosis 1972;16:141-154.
Gil-Peralta A, Alter M, Lai SM, et al. Duplex Doppler and spectral flow analysis of racial differences in cerebrovascular atherosclerosis. Stroke 1990;21:740-744.
Heyman A, Fields WS, Keating RD. Joint study of extracranial arterial occlusion. VI. Racial differences in hospitalized patients with ischemic stroke. JAMA 1972;222:285-289.
Dr. Vaccarino replies: We agree with Dr. Kuller that primary prevention of cardiovascular disease, focused on reducing risk factors, in particular hypertension and diabetes, is crucial for reducing disparities in outcomes related to cardiovascular disease between blacks and whites. However, our study was focused on treatment differences in a sample of patients with acute myocardial infarction. It was not our objective to examine overall causes of race-related health disparities in cardiovascular disease. Treating and controlling risk factors in black patients, as in white patients, to prevent cardiovascular disease are clearly important; however, also important is equity in treatment of persons with established cardiovascular disease.1 To address this question better, we focused on management strategies that have demonstrated efficacy in improving prognosis in this patient population.2 Our research question is not in contraposition to a primary-prevention approach to reducing disparities; it is a different area of investigation.
Dr. Freedman and coworkers argue that differences in susceptibility to or severity of cardiovascular disease according to race, as shown by a lower prevalence of calcified plaques and a lower rate of cardiovascular disease among blacks, as compared with whites, probably play a role in explaining differences in the management of acute myocardial infarction. Although these differences may explain differences in the susceptibility to acute coronary events, they should not influence the management of the disease in patients who have a clinically confirmed acute myocardial infarction. Whether a smaller proportion of black patients than white patients in the general population have calcified lesions is immaterial to whether blacks with an acute myocardial infarction should receive guideline-recommended treatment, such as reperfusion therapy. Future research is needed to improve our understanding of processes underlying persistent racial variation in the treatment of patients hospitalized for acute myocardial infarction.
Viola Vaccarino, M.D., Ph.D.
Emory University School of Medicine
Atlanta, GA 30306
viola.vaccarino@emory.edu
for the National Registry of Myocardial Infarction Investigators
References
Smedley BD, Stith AY, Nelson AR, eds. Unequal treatment: confronting racial and ethnic disparities in health care. Washington, D.C.: National Academy Press, 2003.
Ryan TJ, Antman EM, Brooks NH, et al. 1999 Update: ACC/AHA guidelines for the management of patients with acute myocardial infarction: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Management of Acute Myocardial Infarction). J Am Coll Cardiol 1999;34:890-911.
Dr. Jha and colleagues reply: We agree with Dr. Kuller that the reduction of key risk factors for cardiovascular disease is important in improving health outcomes for white and black Americans, and some studies suggest that there may not be large differences in this area.1 Furthermore, we certainly sympathize with the notion that the United States often fails to spend enough resources on simple public health measures that can have a large impact on people's lives. However, such efforts to fund public health initiatives adequately should not prevent us from ensuring that both white and black Americans have access to tertiary care such as coronary-artery bypass graft surgery and total hip replacement. These procedures, when used appropriately, have a profound effect on people's lives and well-being, and black Americans should benefit from them as much as white Americans do.
We appreciate the point raised by Dr. Akpunonu and colleagues that differences in disease prevalence may account for some of the differences in rates of carotid endarterectomy between whites and blacks. Although blacks have much higher rates of stroke,2 there are data suggesting that part of the increase may be due to higher rates of intracranial carotid disease,3 which would not be amenable to surgical repair. However, an examination of more recent data suggests that there may not be substantial racial differences in the rates of extracranial carotid disease. The Northern Manhattan Stroke Study found similar rates of extracranial carotid disease among whites and blacks,4 and another population-based study found higher rates of large-vessel disease among blacks than among whites.5 Most of the other studies that report on racial differences in intracranial and extracranial carotid disease are limited by not being population based and are often dependent on who is referred for imaging of these vessels.
Therefore, although there might be moderate racial differences in extracranial disease, these differences are unlikely to explain the large racial differences in the rates of carotid surgery. Furthermore, they would certainly not explain the dramatic widening of the gap between whites and blacks in the mid-1990s after the release of results of clinical trials that expanded the indications for these procedures.
Ashish K. Jha, M.D., M.P.H.
Arnold M. Epstein, M.D.
Harvard School of Public Health
Boston, MA 02115
E. John Orav, Ph.D.
Brigham and Women's Hospital
Boston, MA 02115
References
Ma J, Stafford RS. Quality of US outpatient care: temporal changes and racial/ethnic disparities. Arch Intern Med 2005;165:1354-1361.
Kissela B, Schneider A, Kleindorfer D, et al. Stroke in a biracial population: the excess burden of stroke among blacks. Stroke 2004;35:426-431.
Inzitari D, Hachinski VC, Taylor DW, Barnett HJ. Racial differences in the anterior circulation in cerebrovascular disease: how much can be explained by risk factors? Arch Neurol 1990;47:1080-1084.
Sacco RL, Kargman DE, Gu Q, Zamanillo MC. Race-ethnicity and determinants of intracranial atherosclerotic cerebral infarction: the Northern Manhattan Stroke Study. Stroke 1995;26:14-20.
Schneider AT, Kissela B, Woo D, et al. Ischemic stroke subtypes: a population-based study of incidence rates among blacks and whites. Stroke 2004;35:1552-1556.
Dr. Trivedi and colleagues reply: We agree with Dr. Kuller about the importance of reducing racial disparities in the prevention, detection, and treatment of major risk factors and chronic conditions. Indeed, the Health Plan Employer Data and Information Set (HEDIS) measures we studied assess primary and secondary preventive services with substantial health benefits for common medical conditions.1
Dr. Keppel and colleagues raise an important issue about how best to quantify and report disparities over time. Although changes in absolute and relative differences may yield different interpretations in some instances, we would not recommend a single approach to reporting disparities for all measures of health outcomes and utilization.
In our analysis of temporal trends in the HEDIS quality-of-care measures, we chose to report absolute disparities, for several reasons. Most important, absolute differences measure the percentage of eligible health-plan enrollees from the underserved groups who would benefit from the elimination of a disparity, so such measures may be more useful to clinicians and health care managers establishing priorities and programs to improve health care. Second, trends in absolute disparities have a consistent interpretation, regardless of whether the principal outcome is specified as receipt or nonreceipt of a measure. In Table 1 in our article, which Dr. Keppel et al. adapted in their letter, the relative racial disparity in nonreceipt of low-density lipoprotein cholesterol testing among enrollees with cardiovascular disease increased over time, whereas the relative disparity would be decreased if defined as receipt of this test.
Furthermore, changes in absolute and relative disparities may have sharply divergent policy implications depending on the proportions being compared. In particular, relative disparities are greatly magnified when adherence (or nonadherence) approaches 0 or 100 percent. Consider, for example, hypothetical decreases in absolute nonadherence from 90 percent to 2 percent among blacks and from 60 percent to 1 percent among whites. Such changes would represent a substantial decrease in absolute disparity from 30 percent to 1 percent but a paradoxical increase in the corresponding relative disparity from 1.5 to 2.0.
For these reasons, rather than adopt a uniform method of reporting, the decision to report absolute disparities, relative disparities, or both should depend on the purpose of the analysis and the reasoned judgment of the investigators.
Amal N. Trivedi, M.D., M.P.H.
Alan M. Zaslavsky, Ph.D.
John Z. Ayanian, M.D., M.P.P.
Harvard Medical School
Boston, MA 02115
References
Neumann PJ, Levine BS. Do HEDIS measures reflect cost-effective practices? Am J Prev Med 2002;23:276-289.