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Keywords:

  • cardiovascular disorders;
  • coronary heart disease;
  • ethnic groups;
  • incidence;
  • morbidity;
  • risk;
  • Sweden

Abstract

  1. Top of page
  2. Abstract
  3. Introduction
  4. Materials and methods
  5. Materials
  6. Outcome variables
  7. Explanatory variables
  8. Statistical analysis
  9. Results
  10. Discussion
  11. Conflict of interest statement
  12. Acknowledgements
  13. References

Abstract. Gadd M, Johansson S-E, Sundquist J, Wändell P (Family Medicine Stockholm, Karolinska Institutet, Huddinge, Sweden). Morbidity in cardiovascular diseases in immigrants in Sweden. J Intern Med 2003; 254: 236–243.

Introduction. Although immigration to Sweden has increased in the last few decades, the incidence rates of cardiovascular disease and coronary heart disease in immigrants are unknown. The aim of the present study is to estimate whether place of birth affects the incidence rates of cardiovascular disease and coronary heart disease.

Material and methods. The study was designed as a follow-up study on morbidity in cardiovascular disease and coronary heart disease between 1 January 1997 and 31 December 1998, including three and a half million persons with age range 35–64 years, of whom 550 000 were born abroad, from the database MigMed consisting of the whole Swedish population. Incidence rates and relative risks were estimated by indirect standardization and a proportional hazard model.

Results. The age-adjusted risk of coronary heart disease was higher in most foreign-born groups than in Swedes. For example, in nine of 12 male groups, the relative risks varied between 1.1 and 2.2, and in seven of 12 female groups, the relative risks varied between 1.4 and 2.5. When also adjusting for level of education and employment status, the risks were still high, but on a lower level.

Conclusions.  Foreign-born people possess an over-risk of cardiovascular or coronary heart disease(CVD/CHD) compared with Swedish-born persons, also when level of education and employment status are taken into account.


Introduction

  1. Top of page
  2. Abstract
  3. Introduction
  4. Materials and methods
  5. Materials
  6. Outcome variables
  7. Explanatory variables
  8. Statistical analysis
  9. Results
  10. Discussion
  11. Conflict of interest statement
  12. Acknowledgements
  13. References

The continuously rising flow of international migration has made the topic of health and immigration increasingly important worldwide. However, there is a lack of follow-up studies in the international literature demonstrating incidence rates of cardiovascular disease (CVD) and coronary heart disease (CHD) in a broad range of immigrants.

In some studies, immigrants are shown to have decreased morbidity compared with natives – the healthy migrant effect [1, 2]. In contrary, deteriorating health is observed amongst immigrant populations compared with native-born people in Europe [3, 4]. Further, the incidence-rates of CVD/CHD are decreasing in the western world today but information about the rates in women are lacking [5–7]. This follow-up study will be the first to estimate incidence rates of CVD/CHD morbidity in 12 groups of immigrants born abroad and with a residence permit to stay in Sweden.

In Sweden, immigration has increased in the last few decades, and in 31 December 2001 11.5% of the total population were first-generation immigrants. In the 1950s and 1960s immigrants arrived to meet an increasing need for industrial labour (e.g. from Finland and South Europe). In the 1970s and 1980s the immigrants were mainly political refugees (from Poland, Turkey, Latin America, the Middle East, Asia and Africa), as during the 1990s (from the Balkans), when high-skilled workers from OECD countries (e.g. USA, Canada, Australia, New Zealand, Japan and West Europe except for Finland and South Europe), particularly the European Union, also arrived. However, there is a lack of representative and comparative follow-up data on CVD and CHD in foreign-born subjects and natives in most countries in Europe and the USA. Using the new research database MigMed at Karolinska Institutet, including the whole population, it is possible to study incidence rates in CVD and CHD in all foreign-born people and natives in Sweden.

Few studies have focused on the relationship between place of birth and CVD. For example, a case–control study between 1974 and 1976 of southern Stockholm showed that Finnish-born men had a 70% over-risk of CHD compared with Swedish-born. After living in Sweden for 20 years the risk decreased but was still higher than for Swedish men [8]. Social and cultural factors might account for the increased incidence rates of CHD amongst Japanese immigrants living in Hawaii and California [9–11] or in Brazil [12] compared with those living in Japan. With acculturation a previous healthy lifestyle may deteriorate [13]. Studies from the UK showed that immigrants from India, Pakistan and Bangladesh, and Indians from East Africa had an over-risk of CHD independent of regional, cultural and religious differences [14, 15]. Further studies have reported an over-risk of CHD in immigrants compared with natives [8, 14, 16, 17]. A majority of these studies with the focus on place of birth and CVD/CHD have made important contributions to the scientific literature but have some methodological limitations, e.g. small sample sizes, including only men, limited reception areas for inclusion in the studies, or not taking socio-economic status (SES) into consideration. Considering SES is important because of the well-documented association between SES and morbidity in CVD. For example, individuals who possess low SES suffer from higher overall morbidity than their SES counterparts [18–21]. In this follow-up study, it is analysed whether place of birth is a risk factor for morbidity in CVD/CHD in a sample with three and a half million persons in the age range 35–64 years, of whom 550 000 were born abroad, adjusting for age and SES.

The aim of the present study is to estimate whether foreign-born people have higher incidence rates or risks of CVD/CHD than Swedes. It is hypothesized that place of birth (born abroad) is a risk factor of morbidity in CVD/CHD. Moreover, it is also hypothesized that SES, i.e. achieved level of education and employment status, may explain a possible association between place of birth and CVD/CHD.

Materials

  1. Top of page
  2. Abstract
  3. Introduction
  4. Materials and methods
  5. Materials
  6. Outcome variables
  7. Explanatory variables
  8. Statistical analysis
  9. Results
  10. Discussion
  11. Conflict of interest statement
  12. Acknowledgements
  13. References

Incidence rates (IR) and relative risks (RR) of CVD and CHD in this follow-up study of people in the age range 35–64 years were based on cases occurring between 1 January 1997 and 31 December 1998.

MigMed is built up with linkages to several other databases: Louise: A register including the entire population in the range of 35–64 years, 1 656 089 women and 1 697 743 men, of whom 234 938 women and 233 045 men were born abroad. The database contains specifications of education and employment. The Immigration Register has data on place of births. The Total Population Register (RTP) consists of all individuals who have a residence permit. People who stay more than 6 months in Sweden will have a permit and are included in RTP (and MigMed). The Cause of Death Register comprises all causes of death during the year in question, irrespective of whether the death occurred in Sweden or abroad for those who were registered in Sweden at the time of death. The In-care Register is based on WHO recommendations and contains hospital admissions (dates of admission and discharge, diagnoses and other admission data) for CVD according to international classification of diagnoses (ICD)9 and ICD10. A 10-digit personal identification number, assigned to each person in Sweden for their lifetime, including refugees and immigrants staying more than 6 months, is recorded in all registers and was used for record linkage between the 10 registers forming MigMed.

Incidence rates (IR) were defined as first admission for CVD and CHD per 1000 person-years at risk. Person-years at risk were calculated from 1 January 1997 until the first CVD/CHD event, or until death for any reason, and subjects who did not contract CVD/CHD were censored at the end of the study period (31 December 1998). Further, RRs were calculated using the Swedish natives as a reference population.

Outcome variables

  1. Top of page
  2. Abstract
  3. Introduction
  4. Materials and methods
  5. Materials
  6. Outcome variables
  7. Explanatory variables
  8. Statistical analysis
  9. Results
  10. Discussion
  11. Conflict of interest statement
  12. Acknowledgements
  13. References

The CVD morbidity according to ICD9 (390–458) and ICD10 (I00–I82). Morbidity was defined as first admission to hospital as a result of CVD.

The CHD morbidity according to ICD9 (410–414) and ICD10 (I20–I25). Morbidity was defined as first admission to hospital as a result of CHD.

Place of birth (born abroad or in Sweden). Foreign-born people from single countries were fused into larger groups of countries when the number of immigrants statistically was too small, provided that there were geographical, cultural and economic similarities. Thirteen countries or groups of countries were defined: Sweden (reference group), Finland, OECD (e.g. USA, Canada, Australia, New Zealand, Japan and West Europe except for Finland and South Europe), South Europe (Portugal, Spain, Italy, Cyprus, Greece and ex-Yugoslavia), Poland, East European countries (Estonia, Latvia, Lithuania, Romania, Slovakia, the Czech Republic, Hungary, Albania, Bulgaria, Croatia, Macedonia, Moldavia, Slovenia, Russia, Soviet Union, Armenia, Azerbaijan, Georgia, Kazakhstan, Kirgizstan, Tadzhikistan, Turkmenistan, Ukraine, Uzbekistan, Belarus), Bosnia, Latin America, Turkey, Iran, Iraq/Arabic-speaking countries, Asia (except Turkey, Iraq and Arabic-speaking countries) and Africa (except Arabic-speaking Northern Africa). Socio-economic status (SES) was defined as attained level of education and occupational status. According to the attained level of education, the subjects were divided into three groups: (i) primary school (≤11 years); (ii) 2–3 years of completed high school or 2 years of completed college (11–14 years); (iii) 3 years or more of completed college or university studies (≥14 years). Occupational status was defined as (i) employed, or (ii) nonemployed.

Statistical analysis

  1. Top of page
  2. Abstract
  3. Introduction
  4. Materials and methods
  5. Materials
  6. Outcome variables
  7. Explanatory variables
  8. Statistical analysis
  9. Results
  10. Discussion
  11. Conflict of interest statement
  12. Acknowledgements
  13. References

The results are presented as age-adjusted incidence rates by sex. The age-adjusted incidence rate were calculated by indirect standardization using Sweden as a standard population [38].

Cox regression was used to estimate the relative risks (RR) with 95% confidence intervals (CI). The results are presented in two different models; the first model was adjusted for age, the second model also for attained level of education and occupational status. Women and men were analysed separately. The effect of SES in the entire group were also analysed (fusing all separate immigrant-groups into one) to find out whether the well-established effect of these factors on morbidity in CVD/CHD also existed in the present data. There were no first-order interactions between age, place of birth and SES.

Results

  1. Top of page
  2. Abstract
  3. Introduction
  4. Materials and methods
  5. Materials
  6. Outcome variables
  7. Explanatory variables
  8. Statistical analysis
  9. Results
  10. Discussion
  11. Conflict of interest statement
  12. Acknowledgements
  13. References

In general, men had almost twice as high incidence rates of CVD as women. The median incidence rate (per 1000 person-years) for men was 14.24 (8.79–18.94) and for women 8.15 (4.35–11.80). Latin Americans had the lowest incidence rates, and the highest incidence rates were found for Finns, Poles, Bosnians, Turks, Asians and Iraqis, both sexes included, and among Iranian women. In men and women from Sweden, OECD countries, South Europe, East Europe, Africa and Iran, the CVD incidence rates were close to the median (Table 1).

Table 1.  Age-standardized incidence rates per 1000 person-years at risk of cardiovascular disease (CVD) [international classification of diagnoses (ICD): 390–453, I00–I82] in men and women aged 35–64 years
Country of birthIncidence (adj. for age)
MenWomen
Sweden12.86.7
Finland18.99.8
OECD countries13.16.4
South Europe13.98.2
Poland16.78.2
East Europe14.26.6
Bosnia16.211.8
Latin America8.85.6
Turkey17.810.7
Iran13.99.5
Iraq, etc.18.210.8
Asia15.97.0
Africa11.24.4

Men had almost twice to three times as high incidence rates of CHD as women. The median incidence rate for men was 9.15 (4.69–11.48) and for women 2.95 (1.53–5.47). The lowest incidence rates were observed in the African group, both sexes included. Finns, Poles, Bosnians, Turks, Iranians and Iraqis, both sexes included, along with men from South Europe, had the highest incidence rates of CHD. For those born in Sweden, OECD countries, East Europe and Asia, incidence rates close to median were observed (Table 2).

Table 2.  Age-standardized incidence rates per 1000 person-years at risk for coronary heart disease (CHD) [international classification of diagnoses (ICD): 410–414, I20–I25] in men and women aged 35–64 years
Country of birthIncidence (adj. for age)
MenWomen
Sweden5.62.1
Finland9.53.9
OECD countries6.12.1
South Europe7.43.0
Poland10.13.6
East Europe6.92.3
Bosnia9.25.5
Latin America4.72.6
Turkey11.15.0
Iran10.14.8
Iraq, etc.11.55.2
Asia9.22.4
Africa5.31.5

The risk of falling ill with CVD was, in general, higher in people born abroad. For people from OECD countries, East Europe and Africa, including both sexes, the risk did not differ from that for the Swedes, and the same applied to women from Asia and Latin America and men from Iran and South Europe. In men from Latin America, the risk was lower than in Swedish-born people (Table 3).

Table 3.  Relative Risk (RR) and 95% confidence interval (CI) for CVD and CHD in a model adjusted for age (model I) and in another model adjusted for age, level of education and employment status (model II) for the ages 35–64 by sex
Country of birthMen RR (CI)Women RR (CI)
Model IModel IIModel IModel II
CVD
Sweden1111
Finland1.48 (1.42–1.54)1.33 (1.28–1.38)1.46 (1.39–1.54)1.33 (1.26–1.40)
OECD countries1.02 (0.97–1.08)1.02 (0.96–1.08)0.96 (0.88–1.04)0.90 (0.83–0.98)
South Europe1.08 (1.00–1.15)0.92 (0.86–0.99)1.23 (1.11–1.37)0.92 (0.82–1.03)
Poland1.34 (1.16–1.54)1.30 (1.13–1.50)1.16 (1.00–1.35)1.04 (0.90–1.20)
East Europe1.10 (1.01–1.19)1.06 (0.98–1.16)0.99 (0.87–1.13)0.92 (0.81–1.04)
Bosnia1.31 (1.15–1.48)1.05 (0.92–1.19)1.70 (1.47–1.96)1.14 (0.98–1.33)
Latin America0.71 (0.60–0.84)0.65 (0.55–0.77)0.88 (0.71–1.08)0.73 (0.59–0.90)
Turkey1.44 (1.24–1.66)1.19 (1.03–1.37)1.52 (1.23–1.88)1.03 (0.84–1.28)
Iran1.07 (0.93–1.23)0.92 (0.80–1.07)1.30 (1.07–1.58)0.96 (0.79–1.17)
Iraq, etc.1.36 (1.23–1.50)1.13 (1.02–1.25)1.53 (1.30–1.81)1.05 (0.89–1.25)
Asia1.27 (1.09–1.48)1.18 (1.02–1.37)1.08 (0.88–1.33)0.86 (0.70–1.06)
Africa0.91 (0.74–1.13)0.82 (0.66–1.01)0.86 (0.58–1.26)0.64 (0.44–0.95)
Level of education
 Low1.46 (1.41–1.51)1.65 (1.57–1.74)
 Medium1.33 (1.29–1.38)1.45 (1.37–1.52)
 High11
Employment status
 Employed11
 Not employed1.54 (1.51–1.57)1.68 (1.63–1.73)
CHD
Sweden1111
Finland1.70 (1.61–1.80)1.52 (1.44–1.62)1.83 (1.69–1.98)1.64 (1.52–1.78)
OECD countries1.09 (1.01–1.19)1.11 (1.02–1.20)1.02 (0.89–1.18)0.97 (0.84–1.12)
South Europe1.32 (1.20–1.46)1.14 (1.04–1.25)1.40 (1.16–1.67)1.02 (0.84–1.22)
Poland1.86 (1.54–2.24)1.89 (1.56–2.28)1.61 (1.28–2.02)1.45 (1.16–1.83)
East Europe1.24 (1.10–1.39)1.23 (1.09–1.38)1.08 (0.87–1.35)1.02 (0.82–1.27)
Bosnia1.73 (1.46–2.06)1.46 (1.23–1.74)2.50 (2.02–3.10)1.69 (1.35–2.13)
Latin America0.88 (0.70–1.12)0.83 (0.66–1.06)1.23 (0.89–1.71)1.02 (0.74–1.42)
Turkey2.22 (1.85–2.66)1.85 (1.54–2.22)2.11 (1.51–2.94)1.40 (1.00–1.96)
Iran1.90 (1.60–2.25)1.72 (1.45–2.04)2.13 (1.59–2.86)1.55 (1.16–2.09)
Iraq, etc.2.14 (1.90–2.43)1.85 (1.64–2.10)2.30 (1.77–2.97)1.57 (1.20–2.05)
Asia1.79 (1.47–2.19)1.74 (1.42–2.12)1.12 (0.76–1.66)0.89 (0.60–1.32)
Africa0.89 (0.63–1.26)0.84 (0.60–1.19)0.64 (0.26–1.53)0.48 (0.20–1.16)
Level of education
 Low1.78 (1.68–1.88)2.00 (1.81–2.21)
 Medium1.58 (1.50–1.67)1.65 (1.50–1.82)
 High11
Employment status
 Employed11
 Not employed1.49 (1.44–1.54)1.71 (1.63–1.80)

The risk of CHD was in general higher in persons born abroad than in the Swedes. The risks for men and women born in OECD countries, Latin America and Africa did not differ from that for the Swedish-born people. Furthermore, no difference in risks was observed in women from East Europe and Asia (Table 3).

In the full model after adjustment for age, attained level of education and occupational status (model II), the high risks of CVD remained for men and women from Finland, in men from Poland, Turkey, Iraq/Arabic-speaking countries and Asians, and there was also an over-risk of these diseases in women from Bosnia (Table 3). In contrast, the risk of CVD was lower for women born in Latin America, OECD countries and Africa and for men born in South Europe than in Swedish-born group. The risk of CVD was about the same as for Swedes for men and women born in East European countries and Iran, for men born in OECD countries, Bosnia, Iran and Africa and for women born in South Europe, Poland, Turkey, Iraq and Arabic-speaking countries and Asia.

For men and women born in Finland, Poland, Bosnia, Turkey, Iran and Iraq/Arabic-speaking countries and for men born in OECD, South Europe, East European countries and Asia there was an over-risk of CHD also after adjustment for SES. In men and women from Latin America and Africa and in women from OECD countries, South Europe, East Europe and Asia, the risk of CHD did not differ from that for the Swedes (Table 3).

Discussion

  1. Top of page
  2. Abstract
  3. Introduction
  4. Materials and methods
  5. Materials
  6. Outcome variables
  7. Explanatory variables
  8. Statistical analysis
  9. Results
  10. Discussion
  11. Conflict of interest statement
  12. Acknowledgements
  13. References

The main finding of this follow-up study was a higher risk of CVD and CHD in many groups of immigrants than in the Swedish reference group, after adjustment for age according to hypotheses made in the present study. The hypothesis that SES, i.e. achieved level of education and employment status, may explain the association between place of birth and CVD/CHD was wrong because the risk differences for CHD remained after adjustment for SES.

In the 1950s and 1960s, immigrants from Finland and South Europe arrived to meet an increasing need for industrial labour. Today the Finnish group is the largest single group of immigrants, and the South Europeans, the third in size. The Finnish immigrants usually had 9-year compulsory school or lesser. These groups have been particularly exposed to unemployment during recessions in the economy, because of low attained level of education and difficulties in getting jobs as a consequence of prejudices. Further, unemployment increases the risk of CHD [22]. In the present study, there was a 70–80% over-risk of CHD in Finnish men and women compared with the Swedish reference group, which was in agreement with the results from a study of CHD in Finnish men in southern Stockholm [8]. The differences did not disappear after adjustment for SES. In the 1970–1990s political refugees from Asia, Turkey, Middle East and from the Balkan region immigrated to Sweden. Most of these groups originated from Muslim cultures and today there are about 270 000 of them living in Sweden. Unlike the workforce immigrants, these refugees are most often well educated. As the rate of unemployment is high, this might have increased the risk of CHD in these groups compared with Swedish-born people. The most obvious over-risk of CHD was observed in the Muslim groups, which was also in agreement with studies from the UK of immigrant Muslims from the Indian subcontinent [14, 15]. The over-risk in these groups did not disappear after adjustment for SES. Thus, foreign-born persons from these countries have a double burden of risk factors, both as being born abroad and as unemployed.

People born in East Europe, especially Poland, are some of the largest foreign-born groups in Sweden, and today about 125 000 subjects originate from these countries, of whom 43 000 are from Poland. They arrived mainly as political refugees from the time after the Second World War until the end of the 1980s. The East European refugees are usually well educated. The risks of CHD in the current study were higher in men from East European countries and Poland and in women from Poland than Swedish-born group, giving the same indication as a study of mortality in foreign-born people in Sweden [16]. After adjustment for SES, the high risk levels remained.

During the 1990s, high-skilled workers from OECD countries, particularly the European Union, also arrived. This group is the one most similar to the Swedish controls as regards level of education and religious, cultural, traditional, socio-economic and psychosocial factors. The risk of CHD in men from OECD countries was higher than in the Swedish reference group, which was also in agreement with the results from studies of Japanese-born people in Hawaii and California [12, 23], with the risk being highest in those living in California.

A single- or multi-factorial genesis might explain the over-risks in these groups, such as differences in smoking habits or other lifestyle factors (e.g. the Mediterranean diet that has been shown to prevent CVD [24, 25]), different genetic predisposition, psychological or cultural differences or effects of the stress during the migration.

In contrast with these findings are the low risks of CHD in people born in Latin America and Africa [26–28]. The mechanism is probably of multi-factorial origin, such as differences in lifestyle factors such as exercise, smoking, or food and cooking habits [24, 25], differences in social life and cultural or genetic predisposition. Further studies regarding differences in risk factors between foreign-born people and Swedes are needed.

The strength of the study presented is the large sample size, consisting of the whole Swedish population in the age range of 35–64 years. Sweden has a more than 200-year-long tradition of registering and administering social, morbidity/mortality and health-care data. In the present study, the database MigMed was used, which is formed by 10 different registers, including the whole Swedish population, and therefore considered to be representative. The combination of data from several registers made it possible to test the proposed study aims. An advantage is the personal identification number assigned to each person, including refugees and immigrants staying more than 6 months in Sweden, which is recorded in all registers and was used for record linkage.

The completion rate of the material is higher than 98%, except for education amongst older immigrants. This is a minor problem, as the immigrants generally are young.

Subjects over 64 years of age were excluded, as this is the usual age of retirement, and we wanted to adjust for employment status. Subjects under 35 years of age were also excluded, as CVD is uncommon in this group. Exclusion of subjects was mainly performed because of age. More than three and a half million subjects were finally included in the study. Few international studies on the relationship between place of birth and CVD have also taken gender into consideration. In the present study, both men and women are included, and presented separately.

One weakness of the study is that data from single registers were not collected specifically for the study aims. Thus, the study lacks data regarding cardiovascular risk factors such as smoking habits, blood pressure, blood lipids, physical inactivity and dietary habits. Further, the study also lacks comparable information about incidence rates and risk of CVD and CHD in the countries of origin, which makes it impossible to assess whether the morbidity and risk increase or decrease during migration. Subjects over 64 years of age were excluded because adjustment for employment had to be made, and therefore there may be an underestimation of the risks of CVD/CHD as these diseases become more frequent with age, especially in women. Furthermore, the information about morbidity is taken from the ‘In-care Register’. As many disorders included in the CVD group are most often investigated, diagnosed and treated in primary health care, the incidence rate of CVD might be underestimated. As regards CHD, most of the subjects are probably treated at hospitals, at least for cardiac infarction and severe angina pectoris, and thereby included in the ‘In-care Register’. Further, it has been shown that the validity of the ICD code for CHD is very high [29]. Regarding CHD the validity of data is probably much higher than for CVD.

In previous literature, the association between SES and morbidity in CVD/CHD has been demonstrated [26, 30–32]. Therefore, it is important to adjust for SES when analysing the relationship between immigrant status and CVD/CHD.

Even if the morbidity and risk in foreign-born people is higher or lower than in Swedes, it might be equal to corresponding natives in the country of origin. Some factors could be expected to increase the risk of CHD in immigrants, as CHD is influenced by physical and psychological stress. Cultural and psychosocial changes in the life as an immigrant in a new country might lead to accentuated physical and psychological stress and, as a consequence, increased the risk of CHD. Secondly, a high frequency of unemployment and a lower level of education in foreign-born people affect the cardiovascular risk profile negatively [22]. Another socio-economic aspect of risk factors for CVD and CHD is working-class affiliation, as lower SES is associated with higher risk [30]. However, when we adjusted for SES, the risks remained high for most people born abroad. Thirdly, lifestyle factors such as smoking, physical inactivity and bad dietary habits, i.e. known risk factors for CVD [33–37], are associated with lower SES and, to some extent, explain the over-risk of CVD/CHD in groups of low SES [17]. Further, there is a difference in risk profiles between Swedes and many groups of foreign-born people [17, 31]. Smoking habits and other lifestyle factors are not taken into consideration in the present study, as no data about this were available in MigMed. Thus, studies of the influence of lifestyle factors on morbidity in CVD/CHD in immigrants are needed. Fourthly, even if many groups of people born abroad originate from countries that show lower incidence rates of CHD than in Swedes, the information about morbidity in many countries is still unreliable and it might even be higher than in Swedes.

The cardiovascular disease risk in foreign-born people is difficult to assess, and few studies have been performed on this subject that also take SES into account. In the current study, an over-risk of CVD/CHD was observed in most groups of immigrants. Therefore, to be able to focus more efficiently on the treatment and prevention of CVD/CHD, place of birth should be carefully adopted as a risk factor in the assessment of the risk of these diseases.

Acknowledgements

  1. Top of page
  2. Abstract
  3. Introduction
  4. Materials and methods
  5. Materials
  6. Outcome variables
  7. Explanatory variables
  8. Statistical analysis
  9. Results
  10. Discussion
  11. Conflict of interest statement
  12. Acknowledgements
  13. References

This work was supported by The Swedish Research Council Grant No. K2001-27X-11651-06C, the Swedish Council for Social Research, the National Institute of Health Grant No. R01-H271084-1, the Knut and Alice Wallenberg Foundation and Stockholm County (Pick-up). We thank Gölin Frank who contributed to the statistical analysis and our Study Group in Cardiovascular Diseases and Diabetes Mellitus that discussed the analysis as well as the design of the preliminary results of the study.

M. Gadd and J. Sundquist designed and implemented the study, which was reviewed by S.-E. Johansson. M. Gadd analysed the data and wrote the report, with help from J. Sundquist and P. Wändell.

References

  1. Top of page
  2. Abstract
  3. Introduction
  4. Materials and methods
  5. Materials
  6. Outcome variables
  7. Explanatory variables
  8. Statistical analysis
  9. Results
  10. Discussion
  11. Conflict of interest statement
  12. Acknowledgements
  13. References
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