oPatientPlus articles are written by UK doctors and are based on research evidence, UK and European Guidelines. They are designed for health professionals to use, so you may find the language more technical than the condition leaflets.
The UK boasts a culturally diverse population with ethnic minorities accounting for almost 8% of the population in the 2001 census. This represented an increase in the percentage of ethnic members of the population by approximately 50% in the decade spanning 1991-2001. The largest ethnic minority group was Indians, followed by Pakistanis, mixed ethnic backgrounds, Black Caribbeans, Black Africans and Bangladeshis.
It is clear that each population group, either that determined by religion or ethnicity, has differences in terms of illness behaviour, seeking assistance with health matters and beliefs about illness. Some of these processes are determined by culture and more work is required to understand these reasons.
Furthermore, some diseases are more prevalent in certain ethnic groups - for example, cardiovascular-related illnesses are more prevalent in men from the Indian subcontinent. This has sparked a lot of interest, and programmes to increase the detection of cardiovascular disease and its risk factors in ethnic groups are underway. Unsurprisingly, most of the surveys have focused on issues such as hypertension, diabetes mellitus and coronary heart disease. Why these differences in predilection for illnesses exist across ethnic groups is unknown. Along similar lines it is important to remember that a large proportion of research is performed with cohorts that presently do not include enough ethnic minority patients, meaning that results may not necessarily correlate to patients from ethnic groups.
This article will focus on the results of two health surveys on ethnic minority groups in England.
Health Survey for England
In 1999 and again in 2004, the Health Survey for England performed surveys on ethnic minority groups. Participants were randomly chosen and then visited by a researcher who obtained survey results. It included adults and children and various parameters were discussed. Following this, a nurse visited some of the participants and undertook various tasks, eg venepuncture, urinalysis, etc.
Ethnic health inequalities
Health inequalities are differences in health status that are driven by inequalities in society. Health is shaped by many different factors, such as lifestyle, material wealth, educational attainment, job security, housing conditions, psychosocial factors, discrimination and the health services. Health inequalities represent the cumulative effect of these factors. They can be passed on from one generation to the next through maternal influences on baby and child development.
Large-scale surveys like the Health Survey for England show that black and minority ethnic groups as a whole are more likely to report ill health, and that ill health among black and minority ethnic people starts at a younger age than in the White British. There is more variation in the rates of some diseases by ethnicity than by other socioeconomic factors. However, patterns of ethnic variation in health are extremely diverse, and interlink with many overlapping factors:
General health and social factors
The survey reported the following:
- Ethnic differences in health vary across age groups, so that the greatest variation by ethnicity is seen among the elderly.
- Ethnic differences in health vary between men and women, as well as between geographical areas.
- Ethnic differences in health may vary between generations. For example, in some black and minority ethnic groups, rates of ill health are worse among those born in the UK than in first-generation immigrants.
- Pakistani, Bangladeshi and Black-Caribbean people report the poorest health.
- Pakistani women and Bangladeshi men were more likely to report the presence of a long-standing illness which limited them on a daily basis. Furthermore, the figures had increased in Pakistani women by almost 10% when compared with the results of the 1999 survey.
- Of more concern, all ethnic minorities reported a severe lack of support, especially people of Pakistani and Bangladeshi origin.
- Indian, East African, Asian and Black African people report the same health as White British.
- Chinese people report better health.
Patterns of ethnic inequalities in health vary from one health condition to the next. For example:
- Overall, cancer rates tend to be lower in black and ethnic minority groups.
- Those from South Asia, the Caribbean and Africa have lower mortality rates from lung cancer because of lower levels of smoking.
- The highest mortality is in people from Ireland and Scotland.
- Ethnic differences in mental health are controversial.
- Black and ethnic minority patients are more likely to receive a diagnosis of mental illness than the White British. Studies show up to seven times higher incidence of psychosis among Black Caribbean people than among the White British.
- However, prevalence of mental illness in the community shows smaller ethnic differences.
- There is evidence of ethnic differences in risk factors for mental illness, such as discrimination, social exclusion and urban living.
- There is also evidence of differences in treatment. For example, Black Caribbean and African people are more likely to enter psychiatric care through the criminal justice system than through contact with the health services.
Ischaemic heart disease (IHD)
- South Asian men are 50% more likely to have IHD than men in the general population.
- Presence of IHD and stroke is higher in men than women (as in the general population).
- Bangladeshis have the highest rates (followed by Pakistanis, then Indians and other South Asians).
- Men born in the Caribbean have a 50% higher mortality from stroke than the general population.
- Risk factors like smoking, blood pressure, obesity and cholesterol fail to account for all these ethnic variations. Socioeconomic factors may play a part.
- Black Caribbean men have a much higher prevalence of stroke - the risk is almost two thirds higher than the general population. Indian men also have a higher risk of stroke (relative risk 1.42). However, high rates of stroke were also seen in Bangladeshi women, Pakistani women and Irish men.
- Furthermore, research from the USA suggests that ethnic minority patients have more severe strokes and may do less well in rehabilitation.
- Interestingly, the prevalence of angina and stroke were lower in both Chinese men and women, especially in the latter group.
Increased burden of cardiovascular disease in ethnic minority groups
The high levels of cardiovascular mortality and morbidity in ethnic minority groups has been under much scrutiny. There are a number of theories as to what is the cause for the observed differences, including genetic variation and dietary influences. It is suggested that the risk factor profile is different in terms of intensity and prevalence, for example:
- Diabetes mellitus:
The 1999 and 2004 surveys both reported that the prevalence of diabetes is greater in men than women. The observed prevalence was markedly higher in Bangladeshi, Pakistani, Indian and Black Caribbean patients. For the Bangladeshi and Pakistani population this represents an almost five times higher prevalence than the general population. There were no significant changes between the prevalence rates when the two surveys were compared. The prevalence of diabetes mellitus in Black Caribbean men was also similar to Indians. However, Black Caribbean women were noted to have the highest prevalence of diabetes mellitus amongst all women.
In the Health Survey for England 2001, the prevalence of hypertension was reported as over 25% in those over 40 years of age and nearly 50% in those aged 80 or over in the general population. Hypertension is more frequently encountered in ethnic minorities, although differences do not reach statistical significance. The average blood pressure is different in the differing ethnic groups. Another difference is the development and presence of target organ damage - for example, Black Caribbean patients have an increased prevalence of left ventricular hypertrophy (a predictor of mortality and morbidity independent of other risk factors).
There is no clear evidence that a difference in lipid levels exists between ethnic minorities. Despite this, plasma lipid concentrations are greater in patients of South Asian descent (ie from the Indian subcontinent and East Africa). This may explain the differences in prevalence of cardiovascular disease seen between them and the Black Caribbean population. Black Caribbean populations appear to have higher high-density lipoprotein (HDL) fractions and lower triglycerides, whereas Pakistani and Bangladeshi men are more likely to have low HDL levels. It is postulated that these changes probably represent genetic variations, eg polymorphism of hepatic lipase genes.
In the 1999 UK health survey, obesity and raised waist-hip ratio were higher in those with cardiovascular disease, and more so in Indian and Bangladeshi women.
Smoking levels in men of ethnic minorities is similar to the general population with a reduction in smoking rates since 1999. The use of chewing tobacco is higher in people of Bangladeshi background, but the rates appear to have decreased in the 2004 survey.
Other theories include:
- The pattern of atherosclerosis is thought to be different in African American and Caucasian patients - but this remains inconclusive. Levels of C-reactive protein (CRP), an inflammatory marker, appear to be higher in ethnic groups and it has been independently associated with cardiovascular disease, although the part it plays in the pathophysiology of atherosclerosis is still poorly understood. Despite this, the 2004 survey did not report any differences in CRP in ethnic minorities compared with the general population.
- Another theory is that genetic differences resulting in changes in the bioavailability of nitric oxide, a potent vasodilator, may be involved.
- The most likely cause for the observed disparity in cardiovascular disease between ethnic groups probably relates to greater risk factor clustering - leading to a metabolic syndrome characterised by dyslipidaemia, obesity and hypertension. This is supported by studies that have shown higher fasting insulin levels in Asian Indians in the USA when compared with Caucasians of a similar age and body mass index. This supports the presence of impaired insulin metabolism and use.
- It is likely that the the increased rate of cardiovascular disease in South Asians is multifactorial, relating to a combination of excess exposure to risk factors (eg environmental such as urban lifestyle), greater susceptibility, presence of a certain risk factor not yet determined and due to the fact there are fewer competing causes of death in this group, eg cancer.
- However, it has been argued that the observed differences actually relate to the fact that ethnic minorities are under-investigated and under-treated.
Cardiovascular disease risk calculation:
- The Framingham study has provided us with valuable insights into the risk factors for cardiovascular disease and the time course of disease. This provided the Framingham risk function to determine the cardiovascular risk in a patient based on their risk factors. However, the cohort of patients has been mainly Caucasian, making it difficult to correlate to ethnic minority groups, Joint British Societies' (JBS) guidelines suggest multiplying calculated risk by 1.5.
- Recently, a risk calculator for determining the 10-year risk of coronary heart disease and cardiovascular disease for ethnic minorities has been developed and is based on the Framingham study.
Approach to reducing the burden of coronary heart disease and cardiovascular disease in ethnic minorities
- In the first instance this should be the same as your management of all patients.
- However, when considering the risk of a patient from a cardiovascular viewpoint we need to take into account their ethnicity - this includes cultural differences.
- The British Heart Foundation (BHF) recommends that practices keep a register with ethnic codes and diseases.
- All patients should have their blood pressure, weight and height checked - these are easy to perform and non-invasive.
- Patients with a strong family history of diabetes, hypertension and hyperlipidaemia should have these parameters regularly checked, eg annually.
- Have a high index of suspicion for the presence of multiple risk factors and use the risk calculator to determine the patient's risk.
- Lifestyle modifications must be reinforced whenever possible and, even if risk is low, eg weight reduction, salt reduction, healthy low-fat diet and increased exercise.
- The above measures may require dedicated services available in the patient's language, eg Gujarati smoking cessation service.
- Hypertension, diabetes mellitus and hyperlipidaemia should be aggressively treated and patients should be educated, eg community ethnic diabetes mellitus meetings with professionals and patients.
Other areas of variation in illness/disease in ethnic minorities which are not covered here include perinatal mortality
Further reading & references
- Population, Ethnicity and Religion - Census 2001; Office for National Statistics
- Population of the United Kingdom: by ethnic group - Census 2001, Office for National Statistics
- Brindle P, May M, Gill P, et al; Primary prevention of cardiovascular disease: a web-based risk score for seven British black and minority ethnic groups. Heart. 2006 Nov;92(11):1595-602. Epub 2006 Jun 8.
- Cardiovascular disease: prevalence and risk factors; Health Survey for England - The Health of Minority Ethnic Groups; 1999
- Ethnicity and Health, Parliamentary Office of Science and Technology, Jan 2007
- Stansbury JP, Jia H, Williams LS, et al; Ethnic disparities in stroke: epidemiology, acute care, and postacute outcomes. Stroke. 2005 Feb;36(2):374-86. Epub 2005 Jan 6.
- Khan JM, Beevers DG; Management of hypertension in ethnic minorities. Heart. 2005 Aug;91(8):1105-9.
- Health Survey for England 2004: The Health of Minority Ethnic Groups - headline tables, National Statistics/Health and Social Care Information Centre
- Ferdinand KC; Coronary artery disease in minority racial and ethnic groups in the United States. Am J Cardiol. 2006 Jan 16;97(2A):12A-19A. Epub 2005 Dec 1.
- Kuller LH; Ethnic differences in atherosclerosis, cardiovascular disease and lipid metabolism. Curr Opin Lipidol. 2004 Apr;15(2):109-13.
- Yancy CW, Benjamin EJ, Fabunmi RP, et al; Discovering the full spectrum of cardiovascular disease: Minority Health Summit 2003: executive summary. Circulation. 2005 Mar 15;111(10):1339-49.
- Unwin N; The metabolic syndrome. J R Soc Med. 2006 Sep;99(9):457-62.
- Memon M, Abbas F, Khaonolakar M, et al; Health issues in ethnic minorities: awareness and action. J R Soc Med. 2002 Jun;95(6):293-5.
- Quirke TP, Gill PS, Mant JW, et al; The applicability of the Framingham coronary heart disease prediction function to black and minority ethnic groups in the UK. Heart. 2003 Jul;89(7):785-6.
- No authors listed; JBS 2: Joint British Societies' guidelines on prevention of cardiovascular disease in clinical practice. Heart. 2005 Dec;91 Suppl 5:v1-52
- ETHRISK® - Ethnic Group CHD Risk Calculator; ETHRISK® - Ethnic Group CHD Risk Calculator (modified Framingham); A modified Framingham CHD and CVD risk calculator for British black and minority ethnic groups
Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. EMIS has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.
Dr Gurvinder Rull
Dr Gurvinder Rull
Dr Helen Huins