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Published in: BMC Public Health 1/2007

Open Access 01-12-2007 | Research article

Record linked retrospective cohort study of 4.6 million people exploring ethnic variations in disease: myocardial infarction in South Asians

Authors: CM Fischbacher, R Bhopal, C Povey, M Steiner, J Chalmers, G Mueller, J Jamieson, D Knowles

Published in: BMC Public Health | Issue 1/2007

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Abstract

Background

Law and policy in several countries require health services to demonstrate that they are promoting racial/ethnic equality. However, suitable and accurate data are usually not available. We demonstrated, using acute myocardial infarction, that linkage techniques can be ethical and potentially useful for this purpose.

Methods

The linkage was based on probability matching. Encryption of a unique national health identifier (the Community Health Index (CHI)) ensured that information about health status and census-based ethnicity could not be ascribed to an identified individual. We linked information on individual ethnic group from the 2001 Census to Scottish hospital discharge and mortality data.

Results

Overall, 94% of the 4.9 million census records were matched to a CHI record with an estimated false positive rate of less than 0.1 %, with 84.9 – 87.6% of South Asians being successfully linked. Between April 2001 and December 2003 there were 126 first episodes of acute myocardial infarction (AMI) among South Asians and 30,978 among non-South Asians. The incidence rate ratio was 1.45 (95% CI 1.17, 1.78) for South Asian compared to non-South Asian men and 1.80 (95% CI 1.31, 2.48) for South Asian women. After adjustment for age, sex and any previous admission for diabetes the hazard ratio for death following AMI was 0.59 (95% CI 0.43, 0.81), reflecting better survival among South Asians.

Conclusion

The technique met ethical, professional and legal concerns about the linkage of census and health data and is transferable internationally wherever the census (or population register) contains ethnic group or race data. The outcome is a retrospective cohort study. Our results point to increased incidence rather than increased case fatality in explaining high CHD mortality rate. The findings open up new methods for researchers and health planners.
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Literature
1.
go back to reference Bhopal RS: Ethnicity, race, and health in multicultural societies; foundations for better epidemiology, public health, and health care. 2007, Oxford: Oxford University Press, 357-CrossRef Bhopal RS: Ethnicity, race, and health in multicultural societies; foundations for better epidemiology, public health, and health care. 2007, Oxford: Oxford University Press, 357-CrossRef
4.
go back to reference Hammar N, Nerbrand C, Ahlmark G, Tibblin G, Tsipogianni A, Johansson S, Wilhemsen L, Jacobsson S, Hansen O: Identification of Cases of Myocardial Infarction: Hospital Discharge Data and Mortality Data Compared to Myocardial Infarction Community Registers. International Journal of Epidemiology. 1991, 20: 114-120. 10.1093/ije/20.1.114.CrossRefPubMed Hammar N, Nerbrand C, Ahlmark G, Tibblin G, Tsipogianni A, Johansson S, Wilhemsen L, Jacobsson S, Hansen O: Identification of Cases of Myocardial Infarction: Hospital Discharge Data and Mortality Data Compared to Myocardial Infarction Community Registers. International Journal of Epidemiology. 1991, 20: 114-120. 10.1093/ije/20.1.114.CrossRefPubMed
5.
go back to reference Hattersley L, Creeser R: Longitudinal Study 1971–1991 – History, organisation and quality of data. 1995, London, HMSO Hattersley L, Creeser R: Longitudinal Study 1971–1991 – History, organisation and quality of data. 1995, London, HMSO
7.
go back to reference Quantin C, Bouzelat H, Allaert FA, Benhamiche AM, Faivre J, Dusserre L: How to ensure data security of an epidemiological follow-up: quality assessment of an anonymous record linkage procedure. Int J Med Inf. 1998, 49 (1): 117-122. 10.1016/S1386-5056(98)00019-7.CrossRef Quantin C, Bouzelat H, Allaert FA, Benhamiche AM, Faivre J, Dusserre L: How to ensure data security of an epidemiological follow-up: quality assessment of an anonymous record linkage procedure. Int J Med Inf. 1998, 49 (1): 117-122. 10.1016/S1386-5056(98)00019-7.CrossRef
8.
go back to reference Churches T, Christen P: Some methods for blindfolded record linkage. BMC Medical Informatics and Decision Making. 2004, 4 (1): 9-10.1186/1472-6947-4-9.CrossRefPubMedPubMedCentral Churches T, Christen P: Some methods for blindfolded record linkage. BMC Medical Informatics and Decision Making. 2004, 4 (1): 9-10.1186/1472-6947-4-9.CrossRefPubMedPubMedCentral
9.
go back to reference Khunti K, Samani N: Coronary heart disease in people of South Asian origin. Lancet. 2004, 364: 2077-2078. 10.1016/S0140-6736(04)17563-6.CrossRefPubMed Khunti K, Samani N: Coronary heart disease in people of South Asian origin. Lancet. 2004, 364: 2077-2078. 10.1016/S0140-6736(04)17563-6.CrossRefPubMed
10.
go back to reference Gill PS, Kai J, Bhopal RS, Wild S: Health Care Needs Assessment: Black and Minority Ethnic Groups. Health Care Needs Assessment. The epidemiologically based needs assessment reviews. Third Series. Edited by: Stevens, A etal. 2007, Abingdon: Radcliffe Medical Press Ltd, [http://hcna.radcliffe-oxford.com/bemgframe.htm] Gill PS, Kai J, Bhopal RS, Wild S: Health Care Needs Assessment: Black and Minority Ethnic Groups. Health Care Needs Assessment. The epidemiologically based needs assessment reviews. Third Series. Edited by: Stevens, A etal. 2007, Abingdon: Radcliffe Medical Press Ltd, [http://​hcna.​radcliffe-oxford.​com/​bemgframe.​htm]
11.
go back to reference Bhopal R, Unwin N, White M, Yallop J, Walker L, Alberti K, Harland J, Patel S, Ahmad N, Turner C, Watson B, Kaur D, Kulkarni A, Laker M, Tavridou A: Heterogeneity of coronary heart disease risk factors in Indian, Pakistani, Bangladeshi and European origin populations: cross sectional study. BMJ. 1999, 319: 215-220.CrossRefPubMedPubMedCentral Bhopal R, Unwin N, White M, Yallop J, Walker L, Alberti K, Harland J, Patel S, Ahmad N, Turner C, Watson B, Kaur D, Kulkarni A, Laker M, Tavridou A: Heterogeneity of coronary heart disease risk factors in Indian, Pakistani, Bangladeshi and European origin populations: cross sectional study. BMJ. 1999, 319: 215-220.CrossRefPubMedPubMedCentral
12.
go back to reference Cappuccio FP, Cook DG, Atkinson RW, Strazzullo P: Prevalence, detection, and management of cardiovascular risk factors in different ethnic groups in south London. Heart. 1997, 78: 555-563.CrossRefPubMedPubMedCentral Cappuccio FP, Cook DG, Atkinson RW, Strazzullo P: Prevalence, detection, and management of cardiovascular risk factors in different ethnic groups in south London. Heart. 1997, 78: 555-563.CrossRefPubMedPubMedCentral
13.
go back to reference McKeigue P, Marmot M: Obesity and coronary risk factors among south Asians. Lancet. 1991, 337: 972-CrossRef McKeigue P, Marmot M: Obesity and coronary risk factors among south Asians. Lancet. 1991, 337: 972-CrossRef
14.
go back to reference UK Department of Health: Health Survey for England: the Health of Minority Ethnic Groups '99. 2001, London, The Stationary Office UK Department of Health: Health Survey for England: the Health of Minority Ethnic Groups '99. 2001, London, The Stationary Office
15.
go back to reference Bhopal R: What is the risk of coronary heart disease in South Asians? A review of UK research. J Public Health Med. 2000, 22: 375-385. 10.1093/pubmed/22.3.375.CrossRefPubMed Bhopal R: What is the risk of coronary heart disease in South Asians? A review of UK research. J Public Health Med. 2000, 22: 375-385. 10.1093/pubmed/22.3.375.CrossRefPubMed
16.
go back to reference Tunstall-Pedoe H, Clayton D, Morris J, Brigden W, McDonald L: Coronary heart attacks in East London. Lancet. 1975, 2: 833-838. 10.1016/S0140-6736(75)90233-0.CrossRef Tunstall-Pedoe H, Clayton D, Morris J, Brigden W, McDonald L: Coronary heart attacks in East London. Lancet. 1975, 2: 833-838. 10.1016/S0140-6736(75)90233-0.CrossRef
18.
go back to reference Newcombe H: Handbook of record linkage: methods for health and statistical studies, administration and business. 1988, Oxford: Oxford University Press Newcombe H: Handbook of record linkage: methods for health and statistical studies, administration and business. 1988, Oxford: Oxford University Press
19.
go back to reference Harley K, Jones C: Quality of Scottish Morbidity Record (SMR) data. Health Bulletin (Edinburgh). 1999, 54 (5): 410-417. Harley K, Jones C: Quality of Scottish Morbidity Record (SMR) data. Health Bulletin (Edinburgh). 1999, 54 (5): 410-417.
20.
go back to reference Quantin C, Bouzelat H, Allaert FA, Benhamiche AM, Faivre J, Dusserre L: Automatic record hash coding and linkage for epidemiological follow-up data confidentiality. Methods Inf Med. 1998, 37: 271-277.PubMed Quantin C, Bouzelat H, Allaert FA, Benhamiche AM, Faivre J, Dusserre L: Automatic record hash coding and linkage for epidemiological follow-up data confidentiality. Methods Inf Med. 1998, 37: 271-277.PubMed
21.
go back to reference Editorial: Striking the right balance between privacy and public good. Lancet. 2006, 367 (9507): 275-10.1016/S0140-6736(06)68043-4. Editorial: Striking the right balance between privacy and public good. Lancet. 2006, 367 (9507): 275-10.1016/S0140-6736(06)68043-4.
23.
go back to reference Cruickshank JK, Beevers DG, Osbourne VL, Haynes RA, Corlett JC, Selby S: Heart attack, stroke, diabetes, and hypertension in West Indians, Asians, and whites in Birmingham, England. BMJ. 1980, 281: 1108-CrossRefPubMedPubMedCentral Cruickshank JK, Beevers DG, Osbourne VL, Haynes RA, Corlett JC, Selby S: Heart attack, stroke, diabetes, and hypertension in West Indians, Asians, and whites in Birmingham, England. BMJ. 1980, 281: 1108-CrossRefPubMedPubMedCentral
24.
go back to reference Beevers DG, Cruickshank JK: Age, sex, ethnic origin and hospital admission for heart attack and stroke. Postgrad Med J. 1981, 57: 763-765.CrossRefPubMedCentral Beevers DG, Cruickshank JK: Age, sex, ethnic origin and hospital admission for heart attack and stroke. Postgrad Med J. 1981, 57: 763-765.CrossRefPubMedCentral
26.
go back to reference Wilkinson P, Sayer J, Laji K, Grundy C, Marchant B, Kopelman P, Timmis AD: Comparison of case fatality in south Asian and white patients after acute myocardial infarction: Observational study. BMJ. 1996, 312: 1330-1333.CrossRefPubMedPubMedCentral Wilkinson P, Sayer J, Laji K, Grundy C, Marchant B, Kopelman P, Timmis AD: Comparison of case fatality in south Asian and white patients after acute myocardial infarction: Observational study. BMJ. 1996, 312: 1330-1333.CrossRefPubMedPubMedCentral
28.
go back to reference Britton A, Shipley M, Marmot M, Hemingway H: Does access to cardiac investigation and treatment contribute to social and ethnicdifferences in coronary heart disease? Whitehall II prospective cohort study. BMJ. 2004, 329: 318-10.1136/bmj.38156.690150.AE.CrossRefPubMedPubMedCentral Britton A, Shipley M, Marmot M, Hemingway H: Does access to cardiac investigation and treatment contribute to social and ethnicdifferences in coronary heart disease? Whitehall II prospective cohort study. BMJ. 2004, 329: 318-10.1136/bmj.38156.690150.AE.CrossRefPubMedPubMedCentral
30.
go back to reference Harding S, Maxwell R: Differences in mortality of migrants. Health inequalities. Edited by: Drever F, Whitehead M. 1997, London: HMSO, 108-121. Harding S, Maxwell R: Differences in mortality of migrants. Health inequalities. Edited by: Drever F, Whitehead M. 1997, London: HMSO, 108-121.
31.
go back to reference Wild SH, Fischbacher C, Brock A, Griffiths C, Bhopal R: Mortality from all causes and circulatory disease by country of birth in England and Wales 2001–2003. Journal of public health. 2007, 29: 191-198. 10.1093/pubmed/fdm010.CrossRefPubMed Wild SH, Fischbacher C, Brock A, Griffiths C, Bhopal R: Mortality from all causes and circulatory disease by country of birth in England and Wales 2001–2003. Journal of public health. 2007, 29: 191-198. 10.1093/pubmed/fdm010.CrossRefPubMed
32.
go back to reference McKeigue PM, Shah B, Marmot MG: Relation of central obesity and insulin resistance with high diabetes prevalence and cardiovascular risk in South Asians. Lancet. 1991, 337: 382-386. 10.1016/0140-6736(91)91164-P.CrossRefPubMed McKeigue PM, Shah B, Marmot MG: Relation of central obesity and insulin resistance with high diabetes prevalence and cardiovascular risk in South Asians. Lancet. 1991, 337: 382-386. 10.1016/0140-6736(91)91164-P.CrossRefPubMed
33.
go back to reference Mak KH, Chia KS, Kark JD, Chua T, Tan C, Foong BH, Lim YL, Chew SK: Ethnic differences in acute myocardial infarction in Singapore. Eur Heart J. 2003, 24: 151-160. 10.1016/S0195-668X(02)00423-2.CrossRefPubMed Mak KH, Chia KS, Kark JD, Chua T, Tan C, Foong BH, Lim YL, Chew SK: Ethnic differences in acute myocardial infarction in Singapore. Eur Heart J. 2003, 24: 151-160. 10.1016/S0195-668X(02)00423-2.CrossRefPubMed
35.
go back to reference Lowry PJ, Mace PJE, Glover DR, Little WA: The pattern and severity of coronary artery disease in Asians and white living in Birmingham. Postgrad Med J. 1983, 59: 634-635.CrossRefPubMedPubMedCentral Lowry PJ, Mace PJE, Glover DR, Little WA: The pattern and severity of coronary artery disease in Asians and white living in Birmingham. Postgrad Med J. 1983, 59: 634-635.CrossRefPubMedPubMedCentral
36.
go back to reference 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: 143-147.PubMed 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: 143-147.PubMed
37.
go back to reference Liew R, Sulfi S, Ranjadayalan K, Cooper J, Timmis AD: Declining case fatality rates for acute myocardial infarction in South Asian and white patients in the past 15 years. Heart. 2006, 92: 1030-1034. 10.1136/hrt.2005.078634.CrossRefPubMed Liew R, Sulfi S, Ranjadayalan K, Cooper J, Timmis AD: Declining case fatality rates for acute myocardial infarction in South Asian and white patients in the past 15 years. Heart. 2006, 92: 1030-1034. 10.1136/hrt.2005.078634.CrossRefPubMed
38.
go back to reference Gupta M, Doobay AV, Singh N, Anand SS, Raja F, Mawji F, Julian Kho J, Karavetian A, Qilong Y, Yusuf S: Risk factors, hospital management and outcomes after acute myocardial infarction in South Asian Canadians and matched control subjects. CMAJ. 2002, 166: 717-722.PubMedPubMedCentral Gupta M, Doobay AV, Singh N, Anand SS, Raja F, Mawji F, Julian Kho J, Karavetian A, Qilong Y, Yusuf S: Risk factors, hospital management and outcomes after acute myocardial infarction in South Asian Canadians and matched control subjects. CMAJ. 2002, 166: 717-722.PubMedPubMedCentral
39.
go back to reference Lawrence RE, Littler WA: Acute myocardial infarction in Asians and whites in Birmingham. Br Med J. 1985, 290 (6480): 1472-CrossRef Lawrence RE, Littler WA: Acute myocardial infarction in Asians and whites in Birmingham. Br Med J. 1985, 290 (6480): 1472-CrossRef
40.
go back to reference 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: 1578-1583. 10.1016/S0140-6736(97)06243-0.CrossRefPubMed 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: 1578-1583. 10.1016/S0140-6736(97)06243-0.CrossRefPubMed
41.
go back to reference Barakat K, Wells Z, Ramdhany S, Mills PG, Timmis AD: Bangladeshi patients present with non-classic features of acute myocardial infarction and are treated less aggressively in east London, UK. Heart. 2003, 89: 276-279. 10.1136/heart.89.3.276.CrossRefPubMedPubMedCentral Barakat K, Wells Z, Ramdhany S, Mills PG, Timmis AD: Bangladeshi patients present with non-classic features of acute myocardial infarction and are treated less aggressively in east London, UK. Heart. 2003, 89: 276-279. 10.1136/heart.89.3.276.CrossRefPubMedPubMedCentral
42.
go back to reference 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: 511-516. 10.1136/bmj.324.7336.511.CrossRefPubMedPubMedCentral 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: 511-516. 10.1136/bmj.324.7336.511.CrossRefPubMedPubMedCentral
43.
go back to reference Macintyre K, Stewart S, Chalmers J, Pell J, Finlayson A, Boyd J, Redpath A, McMurray J, Capewell S: Relation between socioeconomic deprivation and death from a first myocardial infarction in Scotland: population based analysis. BMJ. 2001, 322: 1152-1153. 10.1136/bmj.322.7295.1152.CrossRefPubMedPubMedCentral Macintyre K, Stewart S, Chalmers J, Pell J, Finlayson A, Boyd J, Redpath A, McMurray J, Capewell S: Relation between socioeconomic deprivation and death from a first myocardial infarction in Scotland: population based analysis. BMJ. 2001, 322: 1152-1153. 10.1136/bmj.322.7295.1152.CrossRefPubMedPubMedCentral
44.
go back to reference Anand S, Yusuf S, Vuksan V, Devanesen S, Teo K, Montague P, Kelemen L, Yi C, Lonn E, Gerstein H: Differences in risk factors, atherosclerosis, and cardiovascular disease between ethnic groups in Canada: the Study of Health Assessment and Risk in Ethnic Groups (SHARE). Lancet. 2000, 356: 279-284. 10.1016/S0140-6736(00)02502-2.CrossRefPubMed Anand S, Yusuf S, Vuksan V, Devanesen S, Teo K, Montague P, Kelemen L, Yi C, Lonn E, Gerstein H: Differences in risk factors, atherosclerosis, and cardiovascular disease between ethnic groups in Canada: the Study of Health Assessment and Risk in Ethnic Groups (SHARE). Lancet. 2000, 356: 279-284. 10.1016/S0140-6736(00)02502-2.CrossRefPubMed
46.
go back to reference Zindrou D, Taylor KM, Bagger JP: Coronary artery size and disease in UK South Asian and Caucasian men. Eur J Cardiothorac Surg. 2006, 29: 492-495. 10.1016/j.ejcts.2006.01.008.CrossRefPubMed Zindrou D, Taylor KM, Bagger JP: Coronary artery size and disease in UK South Asian and Caucasian men. Eur J Cardiothorac Surg. 2006, 29: 492-495. 10.1016/j.ejcts.2006.01.008.CrossRefPubMed
47.
go back to reference Ranganathan M, Bhopal R: Exclusion and Inclusion of Nonwhite Ethnic Minority Groups in 72 North American and European Cardiovascular Cohort Studies. PLoS Medicine. 2006, 3: 0001-0008. 10.1371/journal.pmed.0030044.CrossRef Ranganathan M, Bhopal R: Exclusion and Inclusion of Nonwhite Ethnic Minority Groups in 72 North American and European Cardiovascular Cohort Studies. PLoS Medicine. 2006, 3: 0001-0008. 10.1371/journal.pmed.0030044.CrossRef
Metadata
Title
Record linked retrospective cohort study of 4.6 million people exploring ethnic variations in disease: myocardial infarction in South Asians
Authors
CM Fischbacher
R Bhopal
C Povey
M Steiner
J Chalmers
G Mueller
J Jamieson
D Knowles
Publication date
01-12-2007
Publisher
BioMed Central
Published in
BMC Public Health / Issue 1/2007
Electronic ISSN: 1471-2458
DOI
https://doi.org/10.1186/1471-2458-7-142

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