Does access to cardiac investigation and treatment contribute to social and ethnic differences in coronary heart disease? Whitehall II prosp
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《英国医生杂志》
1 International Centre for Health and Society, Department of Epidemiology and Public Health, University College London Medical School, London WC1E 6BT
Correspondence to: H Hemingway h.hemingway@ucl.ac.uk
Abstract
Low social position and South Asian ethnicity are both associated with increased risk of dying from coronary heart disease,1 2 but the impact of differential access to medical care on these inequalities remains uncertain. If access to coronary management matched coronary incidence, then low social position and South Asian ethnicity would be associated with higher rates of use. For social position, most studies,3-10 but not all,11-13 find the opposite—high social deprivation is associated with lower rates of coronary angiography and revascularisation. Several studies, mainly small and retrospective, report less aggressive treatment of South Asian people with coronary disease compared with white patients.14-22 Such potential healthcare disparities have stimulated calls in the United States and United Kingdom for remedial action.23 24
Three interrelated questions remain unanswered. Firstly, in a general population that exhibits social and ethnic differences in rates of coronary heart disease, do differences exist in access to care? Population studies are lacking; all but a few studies are confined to patients who have sought hospital care for coronary disease and therefore exclude many people with angina in the community.12 Furthermore, studies have concentrated on invasive procedures, ignoring non-invasive investigation and secondary prevention, which may be particularly relevant in primary care. Secondly, how does the social deprivation of an individual patient, as opposed to an area, influence access to cardiac investigation and treatment? Most previous studies have used neighbourhood measures of social deprivation.3-11 One of the few prospective studies reporting individual social class, albeit confined to white men, found no effect on access to coronary angiography but lower revascularisation rates among men from non-manual occupations.25 Thirdly, among South Asians, is the apparent lower use of cardiac investigation and treatment independent of or explained by their social position?26 Previous studies have made little attempt to answer this question.
The Whitehall II prospective cohort study of civil servants offers the opportunity to consider each of these questions. Our objective was to determine whether access to cardiac procedures (exercise electrocardiography, coronary angiography, and coronary revascularisation) and secondary prevention drugs contributes to social and ethnic differences in coronary heart disease in a population setting.
Methods
Table 1 shows that incident coronary morbidity and mortality were higher among lower employment grades than among higher grades and higher among South Asians than among white participants. For example, in men, the age adjusted rate ratio for incident angina and myocardial infarction was 1.66 (95% confidence interval 1.32 to 2.10) for low versus high employment grades and 1.95 (1.28 to 2.96) for South Asians compared with white participants. Risk factors tended to be adverse in low employment grades and among South Asians. South Asians were less likely to be in a high employment grade than were white participants.
Table 1 Age adjusted and mean coronary risk factors at baseline by employment grade and ethnicity and rates of subsequent coronary events
Social position
Men and women in the low employment grades reported higher use of exercise electrocardiography (age adjusted proportion 17.5% in men and 10.6% in women) than did those in the high employment grades (14.7% in men and 8.6% in women) (table 2). When we adjusted for history of coronary heart disease during follow up and baseline risk factors, we found no evidence of an overall grade gradient in either men or women. Men and women in the low employment grades had the highest use of angiography with adjustment for age alone, but no grade differences existed when we added clinical need and other risk factors to the models. Similarly, participants in the low grades had the highest use of revascularisation when we adjusted for age alone, but among men these differences were removed by further adjustment. Employment grade was not associated with taking secondary prevention drugs among the subgroup of participants with a history of angina or myocardial infarction (table 3).
Table 2 Use of exercise electrocardiography, coronary angiography, and coronary revascularisation by employment grade
Table 3 Age adjusted use of secondary prevention drugs by employment grade among participants with a history of angina or myocardial infarction. Values are percentages unless stated otherwise
Ethnicity
South Asian men and women were more likely to have an exercise electrocardiogram or coronary angiography than white participants, even after adjustment for clinical need and employment grade (table 4). We found less evidence for ethnic differences in revascularisation procedures. Further adjustment for presence of the metabolic syndrome or diabetes or abnormality on resting electrocardiogram did not attenuate any of these effects (data not shown). South Asians also tended to be more likely to take secondary prevention drugs than white participants—for example, among men with a history of angina or myocardial infarction, 34% of South Asians were taking blockers compared with 14% of white men (see table on bmj.com).
Table 4 Use of exercise electrocardiography, coronary angiography, and revascularisation by ethnicity
Sex
Women were less likely to have coronary investigations and treatments than men within each grade (table 2) and ethnic group. When adjusted for age, coronary heart disease, employment grade, and ethnicity, the odds ratios of women having an exercise electrocardiogram, angiogram, and revascularisation compared with men were 0.51 (95% confidence intervals 0.42 to 0.62), 0.48 (0.38 to 0.62), and 0.25 (0.15 to 0.40).
Discussion
Shaw M, Dorling D, Gordon D, Davey Smith G. The widening gap: health inequalities and policy in Britain. Bristol: Policy Press, 1999.
Wild S, McKeigue P. Cross sectional analysis of mortality by country of birth in England and Wales, 1970-92. BMJ 1997;314: 705-10.
Gittelsohn AM, Halpern J, Sanchez RL. Income, race, and surgery in Maryland. Am J Public Health 1991;81: 1435-41.
Payne N, Saul C. Variations in use of cardiology services in a health authority: comparison of coronary artery revascularisation rates with prevalence of angina and coronary mortality. BMJ 1997;314: 257-61.
Alter DA, Naylor D, Austin P, Tu JV. Effects of socioeconomic status on access to invasive cardiac procedures and on mortality after acute myocardial infarction. N Engl J Med 1999;341: 1359-67.
MacLeod MCM, Finlayson AR, Findlay IN. Geographic, demographic, and socioeconomic variations in the investigation and management of coronary heart disease in Scotland. Heart 1999;81: 252-6.
Anderson GM, Grumbach K, Luft HS, Roos LL, Mustard CM, Brook R. Use of coronary artery bypass surgery in the United States and Canada: influence of age and income. JAMA 1993;269: 1661-6.
Manson-Siddle CJ, Robinson MB. Superprofile analysis of socio-economic variations in coronary investigation and revascularisation rates. J Epidemiol Community Health 1998:52: 507-12.
Ben-Shlomo Y, Chaturvedi N. Assessing equity in access to health care provision in the UK: does where you live affect your chances of getting a coronary artery bypass graft? J Epidemiol Community Health 1995;49: 200-4.
Coory M, Scott IA, Baade P. Differential effect of socioeconomic status on rates of invasive coronary procedures across the public and private sectors in Queensland, Australia. J Epidemiol Community Health 2002;56: 233-4.
Kee F, Gaffney B, Currie S, O'Reilly D. Access to coronary catheterisation: fair shares for all? BMJ 1993;307: 1305-7.
Morris RW, McCallum AK, Walker M, Whincup PH, Ebrahim S, Shaper AG. Cigarette smoking in British men and selection for coronary artery bypass surgery. Heart 1996;75: 557-62.
Jones M, Ramsey J, Feder G, Crook AG, Hemingway H. Influence of practices' ethnicity or deprivation on access to angiography: an ecological study. Br J General Practice 2004;54: 423-8.
Lowry, PJ, Glover DR, Mace PJ, Littler WA. Coronary artery disease in Asians in Birmingham. Br Heart J 1984;52: 610-3.
Shaukat N, de Bono DP, Cruickshank JK. Clinical features, risk factors, and referral delay in British patients of Indian and European origin with angina matched for age and extent of coronary atheroma. BMJ 1993;307: 717-8.
Dhawan JBC. Angiographic comparison of coronary artery disease between Asians and Caucasians. Postgrad Med 1994;70: 625-30.
Lear JT, Lawrence IG, Burden AC, Pohl JEF. A comparison of stress test referral rates and outcomes between Asians and Europeans. J R Soc Med 1994;87: 661-2.
Lear JT, Lawrence IG, Pohl JE, Burden AC. Myocardial infarction and thrombolysis: a comparison of the Indian and European populations on a coronary care unit. J R Coll Physicians Lond 1994;28: 143-7.
Mukhtar HLW, Littler WA. Survival after myocardial infarction in Asian and white patients in Birmingham. Br Heart J 1995;73: 122-4.
Wilkinson P, Sayer J, Laji K, Grundy C, Marchant B, Kopelman P, et al. Comparison of case fatality in south Asian and white patients after acute myocardial infarction: observational study. BMJ 1996;312: 1330-3.
Goldsmith I, Lip GY, Tsang G, Patel RL. Comparison of primary coronary artery bypass surgery in a British Indo-Asian and white Caucasian population. Eur Heart J 1999;20: 1094-100.
Feder G, Crook AM, Magee P, Banerjee S, Timmis AD, Hemingway H. Ethnic differences in invasive management of coronary disease: prospective cohort study of patients undergoing angiography. BMJ 2002;324: 511-6.
National Institutes of Health. Strategic research plan to reduce and ultimately eliminate health disparities. Bethesda, MD: National Institutes of Health, 2000. (Available at www.nih.gov/about/hd/strategicplan.pdf)
Acheson D. Inequalities in health: report of an independent inquiry. London: Stationery Office, 1998.
Morris RW, Whincup PH, Papacosta O, Walker M, Thompson A. Inequalities in coronary revascularisation during the 1990s—evidence from the British regional heart study. Heart (in press).
Nazroo JY. South Asian people and heart disease: an assessment of the importance of socioeconomic position. Ethn Dis 2001;11: 401-11.
Marmot MG, Smith GD, Stansfeld S, Patel C, North F, Head J, et al. Health inequalities among British civil servants: the Whitehall II study. Lancet 1991;337: 1387-93.
Marmot M, Shipley M, Brunner E, Hemingway H. Relative contribution of early life and adult socioeconomic factors to adult morbidity in the WII study. J Epidemiol Community Health 2001;55: 301-7.
Hemingway H, Shipley M, Britton A, Page M, Macfarlane P, Marmot M. Prognosis of angina with and without a diagnosis: 11 year follow up in the Whitehall II prospective cohort study. BMJ 2003;327: 895-900.
Brunner EJ, Hemingway H, Walker BR, Page M, Clarke P, Juneja M, et al. Adrenocortical, autonomic and inflammatory causes of the metabolic syndrome: nested case-control study. Circulation 2002;106: 2659-65.
Adams P, Hurd MD, McFadden D, Merrill A, Ribeiro T. Healthy, wealthy, and wise? Tests for direct causal paths between health and socioeconomic status. J Econometrics 2003;112: 3-56.
Chaturvedi N, Rai H, Ben-Shlomo Y. Lay diagnosis and health-care seeking behaviour for chest pain in south Asians and Europeans. Lancet 1997;350: 1578-83.
Friscella K, Franks P, Gold MR, Clancy CM. Inequality in quality: addressing socioeconomic, racial, and ethnic disparities in health care. JAMA 2000;283: 2579-84.
Goldman DP, Smith JP. Can patient self-management help explain the SES health gradient? Proc Natl Acad Sci USA 2002;99: 10929-34.
Hemingway H, Crook AM, Feder G, Banerjee S, Dawson JR, Magee P, et al. Underuse of coronary revascularization procedures in patients considered appropriate candidates for revascularization. N Engl J Med. 2001;344: 645-54.
Raine R. Does gender bias exist in the use of specialist health care? J Health Serv Res Policy 2000;5: 237-49.
Hippisley-Cox J, Pringle M, Crown N, Meal A, Wynn A. Sex inequalities in ischaemic heart disease in general practice: cross sectional survey. BMJ 2001;322: 832.
Philpott S, Boynton P, Feder G, Hemingway H. Gender differences in descriptions of angina symptoms and health problems immediately prior to angiography: the ACRE study. Soc Sci Med 2001;52: 1565-75.(Annie Britton, lecturer i)
Correspondence to: H Hemingway h.hemingway@ucl.ac.uk
Abstract
Low social position and South Asian ethnicity are both associated with increased risk of dying from coronary heart disease,1 2 but the impact of differential access to medical care on these inequalities remains uncertain. If access to coronary management matched coronary incidence, then low social position and South Asian ethnicity would be associated with higher rates of use. For social position, most studies,3-10 but not all,11-13 find the opposite—high social deprivation is associated with lower rates of coronary angiography and revascularisation. Several studies, mainly small and retrospective, report less aggressive treatment of South Asian people with coronary disease compared with white patients.14-22 Such potential healthcare disparities have stimulated calls in the United States and United Kingdom for remedial action.23 24
Three interrelated questions remain unanswered. Firstly, in a general population that exhibits social and ethnic differences in rates of coronary heart disease, do differences exist in access to care? Population studies are lacking; all but a few studies are confined to patients who have sought hospital care for coronary disease and therefore exclude many people with angina in the community.12 Furthermore, studies have concentrated on invasive procedures, ignoring non-invasive investigation and secondary prevention, which may be particularly relevant in primary care. Secondly, how does the social deprivation of an individual patient, as opposed to an area, influence access to cardiac investigation and treatment? Most previous studies have used neighbourhood measures of social deprivation.3-11 One of the few prospective studies reporting individual social class, albeit confined to white men, found no effect on access to coronary angiography but lower revascularisation rates among men from non-manual occupations.25 Thirdly, among South Asians, is the apparent lower use of cardiac investigation and treatment independent of or explained by their social position?26 Previous studies have made little attempt to answer this question.
The Whitehall II prospective cohort study of civil servants offers the opportunity to consider each of these questions. Our objective was to determine whether access to cardiac procedures (exercise electrocardiography, coronary angiography, and coronary revascularisation) and secondary prevention drugs contributes to social and ethnic differences in coronary heart disease in a population setting.
Methods
Table 1 shows that incident coronary morbidity and mortality were higher among lower employment grades than among higher grades and higher among South Asians than among white participants. For example, in men, the age adjusted rate ratio for incident angina and myocardial infarction was 1.66 (95% confidence interval 1.32 to 2.10) for low versus high employment grades and 1.95 (1.28 to 2.96) for South Asians compared with white participants. Risk factors tended to be adverse in low employment grades and among South Asians. South Asians were less likely to be in a high employment grade than were white participants.
Table 1 Age adjusted and mean coronary risk factors at baseline by employment grade and ethnicity and rates of subsequent coronary events
Social position
Men and women in the low employment grades reported higher use of exercise electrocardiography (age adjusted proportion 17.5% in men and 10.6% in women) than did those in the high employment grades (14.7% in men and 8.6% in women) (table 2). When we adjusted for history of coronary heart disease during follow up and baseline risk factors, we found no evidence of an overall grade gradient in either men or women. Men and women in the low employment grades had the highest use of angiography with adjustment for age alone, but no grade differences existed when we added clinical need and other risk factors to the models. Similarly, participants in the low grades had the highest use of revascularisation when we adjusted for age alone, but among men these differences were removed by further adjustment. Employment grade was not associated with taking secondary prevention drugs among the subgroup of participants with a history of angina or myocardial infarction (table 3).
Table 2 Use of exercise electrocardiography, coronary angiography, and coronary revascularisation by employment grade
Table 3 Age adjusted use of secondary prevention drugs by employment grade among participants with a history of angina or myocardial infarction. Values are percentages unless stated otherwise
Ethnicity
South Asian men and women were more likely to have an exercise electrocardiogram or coronary angiography than white participants, even after adjustment for clinical need and employment grade (table 4). We found less evidence for ethnic differences in revascularisation procedures. Further adjustment for presence of the metabolic syndrome or diabetes or abnormality on resting electrocardiogram did not attenuate any of these effects (data not shown). South Asians also tended to be more likely to take secondary prevention drugs than white participants—for example, among men with a history of angina or myocardial infarction, 34% of South Asians were taking blockers compared with 14% of white men (see table on bmj.com).
Table 4 Use of exercise electrocardiography, coronary angiography, and revascularisation by ethnicity
Sex
Women were less likely to have coronary investigations and treatments than men within each grade (table 2) and ethnic group. When adjusted for age, coronary heart disease, employment grade, and ethnicity, the odds ratios of women having an exercise electrocardiogram, angiogram, and revascularisation compared with men were 0.51 (95% confidence intervals 0.42 to 0.62), 0.48 (0.38 to 0.62), and 0.25 (0.15 to 0.40).
Discussion
Shaw M, Dorling D, Gordon D, Davey Smith G. The widening gap: health inequalities and policy in Britain. Bristol: Policy Press, 1999.
Wild S, McKeigue P. Cross sectional analysis of mortality by country of birth in England and Wales, 1970-92. BMJ 1997;314: 705-10.
Gittelsohn AM, Halpern J, Sanchez RL. Income, race, and surgery in Maryland. Am J Public Health 1991;81: 1435-41.
Payne N, Saul C. Variations in use of cardiology services in a health authority: comparison of coronary artery revascularisation rates with prevalence of angina and coronary mortality. BMJ 1997;314: 257-61.
Alter DA, Naylor D, Austin P, Tu JV. Effects of socioeconomic status on access to invasive cardiac procedures and on mortality after acute myocardial infarction. N Engl J Med 1999;341: 1359-67.
MacLeod MCM, Finlayson AR, Findlay IN. Geographic, demographic, and socioeconomic variations in the investigation and management of coronary heart disease in Scotland. Heart 1999;81: 252-6.
Anderson GM, Grumbach K, Luft HS, Roos LL, Mustard CM, Brook R. Use of coronary artery bypass surgery in the United States and Canada: influence of age and income. JAMA 1993;269: 1661-6.
Manson-Siddle CJ, Robinson MB. Superprofile analysis of socio-economic variations in coronary investigation and revascularisation rates. J Epidemiol Community Health 1998:52: 507-12.
Ben-Shlomo Y, Chaturvedi N. Assessing equity in access to health care provision in the UK: does where you live affect your chances of getting a coronary artery bypass graft? J Epidemiol Community Health 1995;49: 200-4.
Coory M, Scott IA, Baade P. Differential effect of socioeconomic status on rates of invasive coronary procedures across the public and private sectors in Queensland, Australia. J Epidemiol Community Health 2002;56: 233-4.
Kee F, Gaffney B, Currie S, O'Reilly D. Access to coronary catheterisation: fair shares for all? BMJ 1993;307: 1305-7.
Morris RW, McCallum AK, Walker M, Whincup PH, Ebrahim S, Shaper AG. Cigarette smoking in British men and selection for coronary artery bypass surgery. Heart 1996;75: 557-62.
Jones M, Ramsey J, Feder G, Crook AG, Hemingway H. Influence of practices' ethnicity or deprivation on access to angiography: an ecological study. Br J General Practice 2004;54: 423-8.
Lowry, PJ, Glover DR, Mace PJ, Littler WA. Coronary artery disease in Asians in Birmingham. Br Heart J 1984;52: 610-3.
Shaukat N, de Bono DP, Cruickshank JK. Clinical features, risk factors, and referral delay in British patients of Indian and European origin with angina matched for age and extent of coronary atheroma. BMJ 1993;307: 717-8.
Dhawan JBC. Angiographic comparison of coronary artery disease between Asians and Caucasians. Postgrad Med 1994;70: 625-30.
Lear JT, Lawrence IG, Burden AC, Pohl JEF. A comparison of stress test referral rates and outcomes between Asians and Europeans. J R Soc Med 1994;87: 661-2.
Lear JT, Lawrence IG, Pohl JE, Burden AC. Myocardial infarction and thrombolysis: a comparison of the Indian and European populations on a coronary care unit. J R Coll Physicians Lond 1994;28: 143-7.
Mukhtar HLW, Littler WA. Survival after myocardial infarction in Asian and white patients in Birmingham. Br Heart J 1995;73: 122-4.
Wilkinson P, Sayer J, Laji K, Grundy C, Marchant B, Kopelman P, et al. Comparison of case fatality in south Asian and white patients after acute myocardial infarction: observational study. BMJ 1996;312: 1330-3.
Goldsmith I, Lip GY, Tsang G, Patel RL. Comparison of primary coronary artery bypass surgery in a British Indo-Asian and white Caucasian population. Eur Heart J 1999;20: 1094-100.
Feder G, Crook AM, Magee P, Banerjee S, Timmis AD, Hemingway H. Ethnic differences in invasive management of coronary disease: prospective cohort study of patients undergoing angiography. BMJ 2002;324: 511-6.
National Institutes of Health. Strategic research plan to reduce and ultimately eliminate health disparities. Bethesda, MD: National Institutes of Health, 2000. (Available at www.nih.gov/about/hd/strategicplan.pdf)
Acheson D. Inequalities in health: report of an independent inquiry. London: Stationery Office, 1998.
Morris RW, Whincup PH, Papacosta O, Walker M, Thompson A. Inequalities in coronary revascularisation during the 1990s—evidence from the British regional heart study. Heart (in press).
Nazroo JY. South Asian people and heart disease: an assessment of the importance of socioeconomic position. Ethn Dis 2001;11: 401-11.
Marmot MG, Smith GD, Stansfeld S, Patel C, North F, Head J, et al. Health inequalities among British civil servants: the Whitehall II study. Lancet 1991;337: 1387-93.
Marmot M, Shipley M, Brunner E, Hemingway H. Relative contribution of early life and adult socioeconomic factors to adult morbidity in the WII study. J Epidemiol Community Health 2001;55: 301-7.
Hemingway H, Shipley M, Britton A, Page M, Macfarlane P, Marmot M. Prognosis of angina with and without a diagnosis: 11 year follow up in the Whitehall II prospective cohort study. BMJ 2003;327: 895-900.
Brunner EJ, Hemingway H, Walker BR, Page M, Clarke P, Juneja M, et al. Adrenocortical, autonomic and inflammatory causes of the metabolic syndrome: nested case-control study. Circulation 2002;106: 2659-65.
Adams P, Hurd MD, McFadden D, Merrill A, Ribeiro T. Healthy, wealthy, and wise? Tests for direct causal paths between health and socioeconomic status. J Econometrics 2003;112: 3-56.
Chaturvedi N, Rai H, Ben-Shlomo Y. Lay diagnosis and health-care seeking behaviour for chest pain in south Asians and Europeans. Lancet 1997;350: 1578-83.
Friscella K, Franks P, Gold MR, Clancy CM. Inequality in quality: addressing socioeconomic, racial, and ethnic disparities in health care. JAMA 2000;283: 2579-84.
Goldman DP, Smith JP. Can patient self-management help explain the SES health gradient? Proc Natl Acad Sci USA 2002;99: 10929-34.
Hemingway H, Crook AM, Feder G, Banerjee S, Dawson JR, Magee P, et al. Underuse of coronary revascularization procedures in patients considered appropriate candidates for revascularization. N Engl J Med. 2001;344: 645-54.
Raine R. Does gender bias exist in the use of specialist health care? J Health Serv Res Policy 2000;5: 237-49.
Hippisley-Cox J, Pringle M, Crown N, Meal A, Wynn A. Sex inequalities in ischaemic heart disease in general practice: cross sectional survey. BMJ 2001;322: 832.
Philpott S, Boynton P, Feder G, Hemingway H. Gender differences in descriptions of angina symptoms and health problems immediately prior to angiography: the ACRE study. Soc Sci Med 2001;52: 1565-75.(Annie Britton, lecturer i)