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Regional variations in cardiovascular mortality in Sweden—Structural vulnerability in the local community
Sot. Sci. Med. Vol. 27, No. 9, pp. 911-917, 1988 Printed in Great Britain. All rights reserved
Copyright c
0277-9536/88 53.00 + 0.00 1988 Pergamon Press plc
REGIONAL VARIATIONS IN CARDIOVASCULAR MORTALITY IN SWEDEN-STRUCTURAL VULNERABILITY IN THE LOCAL COMMUNITY BENGT STARRIN, GERRY LARRRONand STEN-OLOF BRENNER The County Council of V&rnland, The Section for Community Medicine, Box 426, S-651 07 Karlstad, Sweden Abstract-The aim of this investigation was to study the connection between various phenomena in the local community and the number of deaths from ischemic heart disease (IHD) for both men and women in the 45-64 age group in the period 19791983. The result reveals considerable regional variation. Those areas with an above average male IHD mortality also tended to differ from the norm as regards labour market, and socioeconomic conditions. There was a tendency for unemployment to be higher, the level of employment to be lower, and the number of households with no or only one person gainfully employed larger; there also tended to be more people who had taken or been forced into early retirement, average incomes tended to be lower and there was an above average proportion of blue-collar workers and a below average proportion of white-collar workers. Furthermore, there proved to be a larger proportion of older men. The factors which did not seem to be related to the number of IHD deaths were the divorce rate in the community and the degree of population density. As regards women, there was a less marked connection between the various regional phenomena and the number of IHD deaths. The mortality rate proved to be related to only two factors: the level of unemployment in the community and the proportion of high-income earners. There was a tendency, albeit weak, that areas with an above average mortality also had an above average rate of unemployment and a lower than average proportion of high-income earners. When the effect of a number of independent variables on IHD mortality in men and women respectively was studied in a stepwise multiple regression analysis, a different picture emerged. It became apparent that only the factors ‘proportion unemployed and ‘proportion of unskilled workers’ were significantly related to the mortality rate. The links between each of the other phenomena and IHD was due to the connection between these phenomena and the factors mentioned above. For women, only the factor ‘proportion unemployed’ was significantly related to the mortality rate. The results are discussed in relation to the degree of vulnerability within the local community. Ker words-cardiovascular ability, stress
mortality, local community, unemployment,
In most of the industrialized countries cardiovascular diseases are the most common cause of death in both men and women. This is particularly the case with men in the 45-64 age group, and most frequently in the form known as ischemic heart disease (IHD)lack of oxygen in the heart muscle. The twentieth century has seen a marked increase in mortality from cardiovascular diseases. However, in some countries a decline in both the incidence of and death from IHD has been noticeable. In an extensive survey of psychosocial factors and cardiovascular diseases in the U.S. it was found that there had been an approx. 20% decline in mortality during the last 10 yr [I]. In Finland the decline commenced later and has been weaker. As regards Sweden, the figures suggest that the curve is now pointing downwards. There was a successive reduction in the number of IHD deaths in the early 80s up to 1983. However, it is too soon to say whether this is a temporary fluctuation or not. The aim of this study is to investigate the multiple links between various phenomena in the local community and IHD mortality in men and women respectively. Our study is limited to the 45-64 age group since death from IHD is relatively uncommon in the lower age groups.
socioeconomic status, vulner-
A PSYCHOSOCIAL FRAME OF REFERENCE
There has been and still is a considerable amount of research into the causes of IHD but so far coronary diseases remain somewhat of a mystery. They take their expression in, among other things, vascular spasms, cardiac infarction, or so-called sudden cardiac death. What is known is that the patient is suffering from at least moderate degrees of coronary arterioscierosis, but not what causes this arteriosclerosis [ 1). Traditional risk factors such as high blood pressure, high levels of blood cholesterol, and smoking are assumed to account for half the occurrences of IHD [2]. Results of research into the links between psychosocial conditions and the incidence of cardiovascular diseases would suggest that psychosocial conditions play a more significant role than has hitherto been assumed. Various theoretical models have been constructed in an attempt to show how psychosocial conditions might be of significance for the incidence of cardiovascular diseases [3-61. The common factor in the assumptions on which the various models are based is that psychosocial conditions are believed to affect the incidence of cardiovascular diseases in two principal ways. Firstly, they 911
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may be said to have an indirect effect in that they lead to changes in, or at least provide a framework for, certain kinds of behaviour and habits, such as the consumption of alcohol, smoking, diet, exercise, and this, in its turn might cause the disease. The indirect effect of psychosocial conditions can be produced either through the intake of material substrates which have a degenerative effect on biological organs (they either break down or create imbalance in vital processes) or through the creation of imbalance between physical rest and physical effort. Secondly, psychosocial conditions would also seem to have an effect on bodily functions directly, via the nervous sytem, through the secretion of hormones such as adrenalin and cortisol, which are both thought to play a significant role in the incidence of cardiovascular diseases. In the latter case, the direct effect is transmitted via a cognitive interpretative process which, in its turn, stimulates biological processes. The perception of a situation as threatening stimulates biological processes different from those stimulated if the situation is seen as peaceful or challenging [7, 81. Demographic conditions and IHD
Epidemiological studies have shown that the incidence of and death from cardiovascular diseases varies in relation to a whole series of demographic conditions, such as social group, income, education, occupation, marital status and age. In most of the industrialized countries it has been found that the incidence of and death from IHD is higher in groups with a lower income and a lower level of education. A health study of the population of North Karelia in Finland revealed that groups with a lower socioeconomic status, that is a lower level of education and lower income, showed a higher incidence of cardiovascular diseases [9]. Similar patterns were found in a study of men and women over the age of 20 in Copenhagen [lo]. The level of education would seem to be significant for the incidence of cardiovascular diseases irrespective of occupational status. In a study of the incidence of IHD in New York and Stockholm it was shown that the disease was more common among those with the lowest level of formal education irrespective of their occupational status [I 11. Throughout, it would seem that the link between IHD mortality and socioeconomic status can be only partially explained by traditional risk factors such as smoking, high blood pressure and diet [ 11.This would suggest that socioeconomic conditions affect the IHD mortality rate irrespective of whether these traditional risk factors are present or not. The differences between different social groups as regards IHD mortality might. to a certain extent. be explained by the economic conditions under which the lower social groups exist and which exert great pressures on them, in many cases making it difficult for them to lead a healthy life. The level of education is probably important for a person’s ability to acquire the knowledge necessary to avoid health risks without professional advice. Aggregate studies, that is studies which elucidate the differences between or within regions or countries, show that improved economic conditions lead to an increase in the average length of life [12]. Perhaps the
most well-known but also the most controversial studies in this field are those by Brenner [13-171. His thesis is that changes in a nation’s economy affect the pattern of mortality in that nation. Periods of economic growth are favourable to the health and well-being of the people, whereas periods of economic stagnation have the opposite effect. In his studies he uses unemployment figures as an indicator of economic decline. On the basis of time series analyses of the relationship between unemployment, ill-health and mortality, Brenner draws the conclusions that there is a connection between increased unemployment and increased mortality. A study of the regional differences in mortality in 76 local authority areas in central Sweden over a IO-yr period revealed that those areas that had the highest IHD mortality were also those with low average income and high unemployment [18]. An attempt to develop a complex model of the connection between social conditions and the incidence of cardiovascular diseases has been made by Karasek, Russel and Theorell [4]. Their model makes use of two central concepts: the degree to which a person has control over their work and the degree of stress in the job. Research suggests that a combination of great demands or a high level of stress, and low control or little opportunity to make one’s own decisions at work, is significant for the incidence of cardiac infarction. The mechanisms controlling this are not known but it is probable that increased blood pressure forms at least part of the link between the two. According to the authors, the combination of great demands and little control at work might give rise to a predominance of catabolic processes, that is processes which break down bodily functions. Work of this type is characterized by continuous physiological activation without any chance for the body to recuperate and rebuild what has been worn and broken down. Catabolic stress reactions entail an increase of the hormones adrenalin, noradrenalin and cortisol as well as an increase in blood pressure, increased pulse rate and greater stimulus of the heart muscle. Since the beginning of the century statistics have shown that married people live longer than those who are divorced or unmarried [19]. Mortality from cardiovascular diseases for American men under 65 is twice as high for those who are single compared to those who are married [20]. In a follow-up study after a IO-yr interval, it was demonstrated that mortality among those surviving an acute cardiac infarction was significantly higher among those who were single, divorced, separated or widowed [21]. A contributory cause to these differences might be that the emotional support a husband and wife give each other has a stress-reducing effect [ 1,211. Women tend to suffer cardiac infarction and sudden death lO-20yr later than men [22]. In older women the incidence of cardiovascular diseases seems to be related not only to age but also to the time when menstruation ceases [23]. On the whole, it would seem that women are less physiologically reactive than men. It is probable, however, that even women’s reactivity is affected by sociocultural factors. Since women are to an increasing extent taking up typical male occupations with their stress producing
Regional variations in cardiovascular mortality conditions, their reactivity would seem to be increasing and becoming more and more like men’s [24]. MODEL AND METHOD
Various social phenomena were studied in 91 local authority areas in Sweden and the data related to deaths from IHD. The analysis of how these different phenomena covaried with the IHD mortality rate was carried out in two stages. Firstly, the bivariate relationships (Pearson) between each of the phenomena and IHD mortality in men and women respectively were studied, and then a multiple regression analysis (stepwise variable selection) was carried out partly to discover hidden and apparent connections and partly to weigh the significance of the various social phenomena for regional variations in IHD. In all the multiple regression analyses the following parameters were used: for entrance to or removal from the model an F value > 4 (P < 0.05) were used. The design used in the investigation is presented in Fig. 1. The IHD figure for men and women respectively is age-standardized and covers the S-yr period 1979-1983. It refers to mortality in the 45-64 age group. The figures include everybody whose cause of
‘INDEPENDENT LABOUR
913
death was given as IHD during the period 1979-1983. Figure 1 shows which years are covered by the different factors and the statistical sources for each factors are specified. One problem is that the different ‘independent’ factors do not exactly cover the same period as the IHD mortality rate (1979-1983). As shown in Fig. 1, there are two factors that cover exactly the same period as the mortality rate namely; the unemployment rate and the divorce rate. For the other ‘independent’ factors the figures vary from 1980 to 1983. However, if the stability is high over time or if the proportions between the different communities are stable over time, the above mentioned problems with different time-periods can be neglected. One factor is probably less stable. namely ‘number of employees affected by bankruptcies’. The figures cover the period 1983 and there is an evident risk that the figures for a single year might give a wrong picture of the relationship between the factor and the dependent variable since it can be assumed that the stability over time is low. An important issue in cross-sectional studies is the problem with time-lag. In the normal case it takes time to develop ischemic heart disease. However, there is reason to believe that in the beginning of a given time period, for example a specific year, there
‘DEPENDENT
FACTORS’
MARKET
in Sweden
FACTORS’
CONDITIONS
Proportion unemployed in age groups 16-64 yearly average for the period 1979-l 983t Proportion of families with only one member gainfully employed in 1982’ Proportion of couples with no member gainfully employed in 1983’ Proportion of men in age group 16-24 gainfully employed in 1982t Proportion of women in age group 16-64 gainfully employed in 1982t Number of employees afffected by bankruptcies/1000 employees in 1983’ INCOME Average income from employment in 1982’ Proportion of men and women in different income groups in 1982’ SOCIOECONOMIC STRUCTURE Proportions in different socioeconomic groups as a percentage of the total population in age group 16-64 in 1980’ DEGREE OF POPULATION
DENSITY
Area’s degree of population density in 1980’ EARLY RETIREMENT Proportion retired early in age group 16-64
in 1982%
DIVORCE RATE Number divorced in relation to total population, average for the years 1979-l 983’ SINGLE-PERSON HOUSEHOLDS Single-person households as a percentage number of households’
of the total
‘Source: National Central Bureau of Statistics. tSource: National Labour Market Board. SSource: National Social Insurance Board.
Fig. I. Research model.
IHD mortality, men 1979-1983’
IHD mortality, women 1979-l
983’
BENGT ~TARRIN er al.
914 Table I Correlation
between different
characteristics in the local community and the IHD (ischemic men and women in age groups 45-64
heart disease) mortality
rate among
IHD mortality
Labour
market
Proportion: Unemployed in age group 16-64 Of families with only one member gainfully employed Of couples with no member gainfully employed Of employed men in age group 16-64 Of employed women in age group l&54 Employees affected by bankruptcies (number of employees affected by bankruptcies/i000
conditions
Socioeconomic
structure
Degree of population Divorce
density
rate
Single person households
Women
0.42*‘* 0.28”’ 0.31*** -0.32*** -0.34*** 0.14
0.26,. 0.15 0.14 -0.08 -0.12 0.03
-0.25.
-0.08
4%!?4
employees)
Average income from employment Proportion of men in different income groups: -39,000 Swedish crowns 40.000-79.000 80,000-I 19.000 I2O,OOa-I 59.000 l6wOOProportion of women in different income groups: -39,000 Swedish crowns 40,00&79,000 80,00&l 19,000 120,00&159,000 160.00&
Income
rate
Men 45-64
-0.04 0.30’” -0.20 -0.27’. -0.22’ 0.05 0.06 0.06 -0.23. -0.23.
Proportion in different socioeconomic groups as a percentage of the total population in age group l&64: Unskilled workers Skilled workers All workers Lower ranking white-collar workers Middle and upper ranking white-collar workers All white-collar workers All employers including self-employed Those at home plus part-time employed (less than I6 hr per/week) Early retired in age group 16-64 years
0.31*** -0.04 0.24. -0.23. -0.33*** -0.31*** 0.03 0.20 0.30***
0.01 0.13 0.09 -0.12 -0.15 -0.15 0.09 0.13 0.06
Degree of population
-0.14
-0.05
Number Proportion
divorced
density
m relation
IO the total population
-0.09
smgle person households
0.00
0.02
0.17
l**P < 0.001; l*P SC0.01; lP < 0.05.
are a group of people who are very close to the critical border to a critical level of manifest disease, and for example to die in ischemic heart disease. This might be caused by accumulated stress or by other circumstances. If the strain among those who are close to a critical level is increasing as a result of, for example, some critical life events the risk for dying in IHD will increase. But on the other hand if the critical life events had not occurred the risk for dying in IHD had decreased. RESULTS
The link between regional characteristics and IHD mortality among men and women respectively is shown in Table 1. It can be seen from the table that in areas with a higher male IHD mortality, total unemployment seems to be above average and the level of employment for both men and women below average. The male IHD mortality rate is also higher in areas where a greater proportion of the households have no or only one person in gainful employment. Male IHD mortality is higher in areas with a lower average income. More specifically, the figures reveal that, in these areas, there is a greater proportion of men with low incomes and a smaller proportion with high incomes.
Furthermore, areas with a smaller proportion of white-collar workers and a larger proportion of blue-collar workers have a higher male IHD mortality. The table also shows that areas with a higher male IHD mortality have a larger proportion of people who have taken or been forced into early retirement. The areas with a higher female mortality have a higher level of unemployment and fewer high-income earners. Multiple regression analyses were carried out separately for men and women. The results of the analysis for men are given in Table 2. It is apparent that only the variables ‘proportion unemployed’ and ‘proportion of unskilled workers’ are significantly related to the IHD mortality rate in men. The links between other factors and IHD mortality are explained by their relation to these two factors. Taken together these two factors account for about 22% of the Table 2. The effects of various factors on the mortality rate from ischemic heart disease in men in the 454 age prow (steowise regression analvsis) Factors Proportion Proportion
unemployed unskilled
Partial
R
0.37 0.22
0.42 0.31
Multiple R = 0.47, R2 = 0.22, P = 12.18775, signif F = 0.0000.
Regional variations in cardiovascular mortality in Sweden Table 3. The effects of various factors on the mortality rate from ischemic heart disease in women in the 45-64 age group (stepwise regression analysis) Factors Proportion
unemployed
Partial
R
0.26
0.26
Multiple R = 0.26, R* = 0.07. F = 6.55818, signif F = 0.0121.
variations in deaths from ischemic heart disease in men. The results of the regression analysis for women are given in Table 3. As can be seen, only the variable ‘proportion unemployed’ is significantly related to IHD mortality in women. The connection between income and IHD deaths revealed in Table 1 is explained by the link between income and unemployment. The unemployment factor accounts for about 7% of the variations in death from ischemic heart disease in women. DlSCUSSlON
Our analysis would, then, seem to suggest that, in the first place, it is the unemployment situation in the local community that is related to the IHD mortality rate, and that this is true for both men and women. It is in those areas with high unemployment that the highest levels of IHD deaths are to be found. Secondly-and this is only valid for men-mortality is linked to the proportion of unskilled workers. Since the study is based on figures for local authorities and not for individuals. there are a number of problems involved in drawing conclusions about the causal connection between the psychosocial environment and deaths at the individual level. It is typical of this kind of aggregate study that the concepts used often have an import that is different to their individual counterparts [25,26]. The aggregate concept ‘proportion unemployed’ probably expresses something different to and something more than the individual concept ‘being unemployed’. High unemployment in a local authority area tells us more than that a certain number of individuals are out of work. It is probable that the age structure of the population, communications, public service etc. are different from those in areas with low unemployment. The problem with aggregate studies like the present one is that there is a risk of drawing conclusions about connections at the individual level. Such a false conclusion here would be to say that those who are unemployed run a greater risk of dying from ischemic heart disease. When considering IHD deaths in men and women in the 45-64 age group two factors must be borne in mind: firstly, that this cause of death is 4-5 times more common in men than in women. In 1983 a little more than 3000 men in Sweden in the 45-64 age group died from ischemic heart disease. The figure for women was 657. Secondly, the results of the multiple regression analysis showed that only a small proportion of the variations in the female mortality rate could be ‘explained’ by the various social phenomena used in the study. The factors which, in the multiple regression analysis, proved to be statistically significant explained about 22% of the regional variations in men, but only 7% in women. This means that,
915
as regards mortality in women, most of the regional variations are-from a statistical viewpoint-unexplained. For this reason, it is perhaps true to say that the speculative reasoning that follows is less valid for theorizing about mortality in women than for that in men. We have shown that some areas have a markedly higher IHD mortality than others. One question we wish to raise is the following: are there certain characteristics, forces or stress factors-in the local community-which are of significance for the incidence of cardiovascular diseases? In order to prevent or delay the onset of the diseases and to be able to reduce the regional variations, it is of importance to identify these characteristics, forces or stress factors. From a psychosocial viewpoint then, it may be asked whether the regional variations in IHD mortality are linked to factors in the social environment in which people live. Before continuing our discussion, we shall make a brief reference to Dahlgren and Martensson’s comments on the concept of vulnerability [27]. The fact that something is vulnerable implies that it contains within itself the conditions necessary for a change in a negative direction: what is vulnerable can easily be damaged. Vulnerability is hidden and latent and not directly visible to man and is, therefore, sometimes difficult to foresee. When Dahlgren and Martensson speak of vulnerability in the local community, area or region, they mean the vulnerability that results from increased dependence on large scale economic and technical systems, i.e. external vulnerability, and the vulnerability in the system’s internal structural conditions and relations. That an area is vulnerable does not mean that it is already marked by social problems or other difficulties or that it will of necessity be so in the future. What it means is that there is greater risk of a negative development. Dahlgren and Martensson dwell on the link between vulnerability and social problems [27]. The characteristic feature of a social problem is that it is visible; it is the object of discussion and debate, and people are aware of its existence even if they may have different views about how to solve it. A social problem is a common concern, which involves norms, values and goals. Social problems thrive in a social system where there is an imbalance between people’s needs, activities and resources. Health problems may be social problems if they meet the requirements of visibility and if there is a general awareness of their existence. In the remainder of our discussion it is not, however, central whether the IHD mortality rate is seen as a social problem or not. The question we can now ask is whether regional variations in IHD may have anything to do with similar variations in the vulnerability of communities. In the introduction we took up two principal ways in which psychosocial conditions might influence the incidence of cardiovascular diseases. Further, we emphasized the need to formulate more complex models of how psychosocial conditions exert this influence. One such complex model has been formulated by Karasek, Russel and Theorell to reveal the link between working conditions and the incidence of cardiovascular and stress-related diseases [4]. The
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BENGT STARRIN et al.
idea is that the lack of opportunity to influence the content and planning of one’s job coupled with great pressure at work creates negative stress. This negative stress may, in its turn, give rise to biological changes which might lead to illness. In Dahlgren and Martensson’s discussion of vulnerability similar ideas are applied to the local community as a whole but they are not related to the incidence of disease. They maintain that an increase in vulnerability within the local community may be described as a successive dissolution of links, overviews and control. A vulnerable community is a community where the opportunities for overview and control are strictly limited, where the inhabitants are no longer really able to determine and influence developments, a power which is in the hands of external decision-makers. Unemployment in a community or local authority area may be said to be both an indicator of vulnerability and a social problem. Depending on its level, it indicates shortcomings in the local community’s ability to influence developments and to meet people’s needs. It may also be said to be a problem in the sense that people recognize it as such, as a common concern to be solved [28]. When a community is hit by unemployment, the effect is much greater than the fact that more and more people are without gainful employment. For one thing, working conditions for those with jobs tend to become tougher. The work rate is increased and paradoxically enough so is overtime work [29]. As unemployment increases. people’s choices on the labour market become limited. It is more difficult to change jobs, at the same time as demands on the work environment are reduced [30]. When a small community or area is hit by unemployment, the social bonds between people tend to dissolve and there is considerable population movement. People have to move to get new jobs and this represents a further significant increase in the pressures on them. In the literature dealing with the link between the development of unemployment and the incidence of cardiovascular diseases one of the major questions discussed is whether variations in mortality are best explained by the increase and decrease of unemployment or by working conditions and other stressrelated factors. Eyer is of the opinion that bad working conditions, overtime work, dissension in the local community and the lack of solidarity probably explain the variations better than unemployment alone does [31). Individual studies show that both unemployment, the threat of unemployment [32-361, tense working conditions [4] and a lot of overtime work (371 can lead to stress-related illnesses. It has been shown that the combination of stressful work and the lack of opportunity to learn new things at work is related to the volume of institutional care for cardiac infarction [38]. In light of this, the link between the proportion of unskilled workers in the community and IHD mortality would seem to be understandable. The work carried out by the unskilled has characteristics which can create unfavourable stress, namely the combination of little control over one’s own work and great pressures. To increase our knowledge of the connection between unemployment and death from IHD, two conditions have to be studied more closely. Firstly, it
is of importance to examine the extent to which and the way in which high unemployment may be said to express a kind of general vulnerability within the local community. Our data and the discussion based on them would suggest that the indicator ‘proportion unemployed’ contains more information about the local community than the concept immediately refers to, namely, the number of unemployed related to the number employable. The fact that unemployment is high within a local community means that the local community is living under economically difficult circumstances. People are exposed to so-called economic stress. It may also be possible that the quality of care of sick individuals for some reason may be poorer in communities with high unemployment rates. Secondly, a closer examination should be made of the manner in which this potential vulnerability or economic stress affects people’s health and wellbeing, and of which groups of people are particularly exposed to it. It is reasonable to assume that two groups are in this difficult position: one being those people who have lost their jobs and the other those who are employed in industries where the threat of unemployment is great or where the chances of influencing one’s work situation is small. In both cases control over one’s own life is limited. If high unemployment is an expression of general vulnerability within the local community, it might be thought to affect people’s health by causing psychophysiological responses, psychopathological reactions and changes in behavioural patterns. This means that traditional risk factors such as smoking, hypertension and so on must be considered. In order to understand and explain these possible causal mechanisms, studies at the individual level are necessary. It is to be hoped that this study at the aggregate level which has attempted to describe the multiple links between macrofactors and IHD, will contribute to pave the way for such studies. REFERENCES 1. Ort-Gomer K., Perski A. and Theorell T. Psykosociala faktorer och hjlrt-och klrlsjukdom. En kunskapsiiversikt. Stockholm. H&o- och sjukvird under 90talet, sou 1984. 2. Jenkins C. D. I. Ischemic Heart Disease. The Strategy of Postponement (Edited by Tybjerg-Hansen A.. Schnohr P. and Rose G.), Vol. I. FADL, K(ipenhamn, 1977. 3. Kagan A. R. and Levi L. Health and EnvironmentPsychosocial SGmuli. A Reuiebx. Contribution to WHO document for the United Nations Conference on the Human Environment. World Health Organization, Geneva, 1972. 4. Karasek R. A., Russel R. S. and Theorell T. Physiology of stress and regeneration in job related cardio vascular illness. J. Human Stress 8, 2942, 1982. 5. Ort-Gomer K. Ischemic heart disease as a result of psychosocial processes. Sot. Sri. Med. 8, 3945, 1974. 6. gjiwall T. Ps)>kosomatisk Medicinhistorik. Definirioner och Framridvperspekrio (Edited bv Mellgren A.). Vol. I. Psykosomat&k medicin; Natur och K&r, Stockholm, 1980. 7. Mason I. W. Specificity in the organization of neuroendocrine respdnse p&files. In Fr&riers in Neurology and Neuroscience Research (Edited bv Seeman P. and Brown G.). University of T&onto, Ii)74.
Regional variations in cardiovascular mortality in Sweden 8. Larsson G. and Anderzen I. Appraisal. coping, catecholamine exretion and psychomotor performance during calm and stressful conditions, Scund. J. Sporrs Sci. 9, 47-51, 1987. 9. Puska P. and Mustaniemi H. Incidence and presentation of myocardial infarction in North Karelia, Finland. Acre med. scand. 197, 21 l-216, 1975. 10. Nyboe J.. Schnohr P. and Jensen G. Mortality by marital status, education and income in Copenhagen in 19761978. The Copenhagen City Heart Study, 1979. Il. Ort-Gomer K. Psychological stress and ischemic heart disease in Stockholm and New York. J. ps.rchosom. Res. 23, 165-173, 1979. 12. Spruit I. Unemployment and health in macro social analysis. Sot. Sci. Med. 16, 1903-1917, 1982. 13. Brenner H. Economic changes and heart disease mortality. Am. J. Publ. Hlrh 61(3), 606611, 1971. 14. Brenner H. Esrimaring lhe Social Costs of Nafional Economic Policy. U.S. Government Printing Office, Washington, D.C., 1976. 15. Brenner H. Mortality and the national economy: a review and the experiences of England and Wales, 19361976. The Lancer 15, 568-573, 1979. 16. Brenner H. Mortality and economic instability. Detailed analyses for Britain and comparative analyses for selected industrialized countries. Inr. J. Hlrh Serv. 13, 563-620, 1983a. 17. Brenner H. Importance of Economic Change in Swedish Health and Social Wellbeing 1950-1980. Socialstyrelsen, Stockholm, 1983b. 18. Nerbrand C., Aberg H.. Rosen M. and Tibblin G. Regionala skillnader i mortalitet i Mellansverige. Liikartidningen
46, 82. 40044008,
1985.
19. Somers A. R. Marital status, health and use of health services: an old relationship revisited. J. Am. med. Ass. 241, 1818-1822, 1979. 20. Lynch J. J. The Broken Heart: The Medical Consequences of Loneliness. Basic Books, New York, 1977. 21. Chandra V., Szklo M. et al. The impact of marital status on survival after an acute myocardial infarction: a population based study. Am. J. Epidem. 117, 32G325, 1983.
22. Dawber T. R. (Ed.) The Framingham Study. The Epidemiology Study. The Epidemiology of Atherosclerotic Diseuse. Harvard University Press. Cambridge, Mass.,
1980. 23. Kannel W. B. and Hjortland M. C. Menopause and risk of cardiovascular disease: the Framingham Study. Ann. intern. Med. 85, 447452.
1976.
24. Watkins L. and Eaker E. Population and demographic influences on reactivity. In Handbook of Srress, Reacriviry & Cardiovascular Disease (Edited by Mathews K. A.,
917
Weiss S. M.. Detre T., Dembrowski T. M., Faulkner B., Manuck S. B. and Williams R. B.). Wiley, New York, 1986. 25. Firebaug G. A rule for inferring individual relations from aggregate data. Am. Social. Rev. 43, 557-572, 1978. 26. Robinson W. S. Ecological correlations and the behavior of individuals. Am. Social. Rev. IS, 351-357, 1950. 27. Dahlgren L. and Martensson B. SGrbarher och Sjtilvtillir. Nord Refo. Oslo. 1983. 28. Mills C. W. Den Sociologiska Visionen. Prisma. Stock-
holm, 1971. B.. Lundberg B.. Angelow B. and Wall H. Unemployment, overtime work and work intensity. Paper presented at the Meeting on Unemplo_vmenr,
29. Starrin
Poverty and Qualify of Working Life-Innovative venrions IO Counteracr Damaging Healrh
InrerEflecrs,
Vienna, 12-14 May, 1987. WHO, Regional Office for Europe. ICP/HSR 818/29. 30. Starrin B., Lundberg B. and Angelow B. Tillsammans Blir vi Slarka. Arbersliishetens Eliinde. Motkamp. Prisma. Stockholm, 1985.
Vardag
och
31. Eyer J. Does unemployment cause the death rate peak in each business cycle. Inr. J. Hlrh Serv. 7, 625662, 1977. Arbersliisher och 32. Angeliiw B. Fiireragsnedliiggningar, Socialpsykologiska Srressreakrioner. Sociologiska insti-
tutionen, Lunds Universitet, 1986. 33. Brenner S.-O. and Levi L. Long-term unemployment among women in Sweden. Sot. Sci. Med. 25.2, 153-161, 1987. Socialmedicinsk 34. Janlert U. Arbelsliisher och Hiilsa-En Studie au Byggnadrarbetare i Luledregionen. Arbets-
marknadsdepartementet,
Stockholm, 1983.
35. Ametz B., Wasserman J., Petrini B., Brenner S.-O., Levi
L., Eneroth P., Salovaara H.. Hjelm R., Salovaara L., Theorell T. and Petterson I.-L. Immune function in unemployed women. Psychosom. Med. 49, 1, 3-12, 1987. Sociala och Hiilsomiissiga 36. Starrin B. Arbersloshefens Konsekvenser-En Lirrerrauriiversikt. Varmlands LIins Landsting, Sektionen for Samhlllsmedicin, Forskningsrapport nr 4, 1986. 37. Theorell T. and Rahe R. H. Behavior prior to myocardial infarction. In Psychological factors in Relarion IO the Onset of Mvocardial Infarction and for Some Metabolic Vari~bles~ A Pilor Study (Edited by Theorell
T.). Karolinska Institute, Stockholm, 1970. L.. Spetz C.-L. and Theorell T. Type of occupation and near-future hospitalization for myocardial infarction and some other diagnoses. Inr. J.
38. Alfredsson
Epidem.
14, 3, 378-388,
1985.
Copyright c
0277-9536/88 53.00 + 0.00 1988 Pergamon Press plc
REGIONAL VARIATIONS IN CARDIOVASCULAR MORTALITY IN SWEDEN-STRUCTURAL VULNERABILITY IN THE LOCAL COMMUNITY BENGT STARRIN, GERRY LARRRONand STEN-OLOF BRENNER The County Council of V&rnland, The Section for Community Medicine, Box 426, S-651 07 Karlstad, Sweden Abstract-The aim of this investigation was to study the connection between various phenomena in the local community and the number of deaths from ischemic heart disease (IHD) for both men and women in the 45-64 age group in the period 19791983. The result reveals considerable regional variation. Those areas with an above average male IHD mortality also tended to differ from the norm as regards labour market, and socioeconomic conditions. There was a tendency for unemployment to be higher, the level of employment to be lower, and the number of households with no or only one person gainfully employed larger; there also tended to be more people who had taken or been forced into early retirement, average incomes tended to be lower and there was an above average proportion of blue-collar workers and a below average proportion of white-collar workers. Furthermore, there proved to be a larger proportion of older men. The factors which did not seem to be related to the number of IHD deaths were the divorce rate in the community and the degree of population density. As regards women, there was a less marked connection between the various regional phenomena and the number of IHD deaths. The mortality rate proved to be related to only two factors: the level of unemployment in the community and the proportion of high-income earners. There was a tendency, albeit weak, that areas with an above average mortality also had an above average rate of unemployment and a lower than average proportion of high-income earners. When the effect of a number of independent variables on IHD mortality in men and women respectively was studied in a stepwise multiple regression analysis, a different picture emerged. It became apparent that only the factors ‘proportion unemployed and ‘proportion of unskilled workers’ were significantly related to the mortality rate. The links between each of the other phenomena and IHD was due to the connection between these phenomena and the factors mentioned above. For women, only the factor ‘proportion unemployed’ was significantly related to the mortality rate. The results are discussed in relation to the degree of vulnerability within the local community. Ker words-cardiovascular ability, stress
mortality, local community, unemployment,
In most of the industrialized countries cardiovascular diseases are the most common cause of death in both men and women. This is particularly the case with men in the 45-64 age group, and most frequently in the form known as ischemic heart disease (IHD)lack of oxygen in the heart muscle. The twentieth century has seen a marked increase in mortality from cardiovascular diseases. However, in some countries a decline in both the incidence of and death from IHD has been noticeable. In an extensive survey of psychosocial factors and cardiovascular diseases in the U.S. it was found that there had been an approx. 20% decline in mortality during the last 10 yr [I]. In Finland the decline commenced later and has been weaker. As regards Sweden, the figures suggest that the curve is now pointing downwards. There was a successive reduction in the number of IHD deaths in the early 80s up to 1983. However, it is too soon to say whether this is a temporary fluctuation or not. The aim of this study is to investigate the multiple links between various phenomena in the local community and IHD mortality in men and women respectively. Our study is limited to the 45-64 age group since death from IHD is relatively uncommon in the lower age groups.
socioeconomic status, vulner-
A PSYCHOSOCIAL FRAME OF REFERENCE
There has been and still is a considerable amount of research into the causes of IHD but so far coronary diseases remain somewhat of a mystery. They take their expression in, among other things, vascular spasms, cardiac infarction, or so-called sudden cardiac death. What is known is that the patient is suffering from at least moderate degrees of coronary arterioscierosis, but not what causes this arteriosclerosis [ 1). Traditional risk factors such as high blood pressure, high levels of blood cholesterol, and smoking are assumed to account for half the occurrences of IHD [2]. Results of research into the links between psychosocial conditions and the incidence of cardiovascular diseases would suggest that psychosocial conditions play a more significant role than has hitherto been assumed. Various theoretical models have been constructed in an attempt to show how psychosocial conditions might be of significance for the incidence of cardiovascular diseases [3-61. The common factor in the assumptions on which the various models are based is that psychosocial conditions are believed to affect the incidence of cardiovascular diseases in two principal ways. Firstly, they 911
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BENGTSTARRIN er al.
may be said to have an indirect effect in that they lead to changes in, or at least provide a framework for, certain kinds of behaviour and habits, such as the consumption of alcohol, smoking, diet, exercise, and this, in its turn might cause the disease. The indirect effect of psychosocial conditions can be produced either through the intake of material substrates which have a degenerative effect on biological organs (they either break down or create imbalance in vital processes) or through the creation of imbalance between physical rest and physical effort. Secondly, psychosocial conditions would also seem to have an effect on bodily functions directly, via the nervous sytem, through the secretion of hormones such as adrenalin and cortisol, which are both thought to play a significant role in the incidence of cardiovascular diseases. In the latter case, the direct effect is transmitted via a cognitive interpretative process which, in its turn, stimulates biological processes. The perception of a situation as threatening stimulates biological processes different from those stimulated if the situation is seen as peaceful or challenging [7, 81. Demographic conditions and IHD
Epidemiological studies have shown that the incidence of and death from cardiovascular diseases varies in relation to a whole series of demographic conditions, such as social group, income, education, occupation, marital status and age. In most of the industrialized countries it has been found that the incidence of and death from IHD is higher in groups with a lower income and a lower level of education. A health study of the population of North Karelia in Finland revealed that groups with a lower socioeconomic status, that is a lower level of education and lower income, showed a higher incidence of cardiovascular diseases [9]. Similar patterns were found in a study of men and women over the age of 20 in Copenhagen [lo]. The level of education would seem to be significant for the incidence of cardiovascular diseases irrespective of occupational status. In a study of the incidence of IHD in New York and Stockholm it was shown that the disease was more common among those with the lowest level of formal education irrespective of their occupational status [I 11. Throughout, it would seem that the link between IHD mortality and socioeconomic status can be only partially explained by traditional risk factors such as smoking, high blood pressure and diet [ 11.This would suggest that socioeconomic conditions affect the IHD mortality rate irrespective of whether these traditional risk factors are present or not. The differences between different social groups as regards IHD mortality might. to a certain extent. be explained by the economic conditions under which the lower social groups exist and which exert great pressures on them, in many cases making it difficult for them to lead a healthy life. The level of education is probably important for a person’s ability to acquire the knowledge necessary to avoid health risks without professional advice. Aggregate studies, that is studies which elucidate the differences between or within regions or countries, show that improved economic conditions lead to an increase in the average length of life [12]. Perhaps the
most well-known but also the most controversial studies in this field are those by Brenner [13-171. His thesis is that changes in a nation’s economy affect the pattern of mortality in that nation. Periods of economic growth are favourable to the health and well-being of the people, whereas periods of economic stagnation have the opposite effect. In his studies he uses unemployment figures as an indicator of economic decline. On the basis of time series analyses of the relationship between unemployment, ill-health and mortality, Brenner draws the conclusions that there is a connection between increased unemployment and increased mortality. A study of the regional differences in mortality in 76 local authority areas in central Sweden over a IO-yr period revealed that those areas that had the highest IHD mortality were also those with low average income and high unemployment [18]. An attempt to develop a complex model of the connection between social conditions and the incidence of cardiovascular diseases has been made by Karasek, Russel and Theorell [4]. Their model makes use of two central concepts: the degree to which a person has control over their work and the degree of stress in the job. Research suggests that a combination of great demands or a high level of stress, and low control or little opportunity to make one’s own decisions at work, is significant for the incidence of cardiac infarction. The mechanisms controlling this are not known but it is probable that increased blood pressure forms at least part of the link between the two. According to the authors, the combination of great demands and little control at work might give rise to a predominance of catabolic processes, that is processes which break down bodily functions. Work of this type is characterized by continuous physiological activation without any chance for the body to recuperate and rebuild what has been worn and broken down. Catabolic stress reactions entail an increase of the hormones adrenalin, noradrenalin and cortisol as well as an increase in blood pressure, increased pulse rate and greater stimulus of the heart muscle. Since the beginning of the century statistics have shown that married people live longer than those who are divorced or unmarried [19]. Mortality from cardiovascular diseases for American men under 65 is twice as high for those who are single compared to those who are married [20]. In a follow-up study after a IO-yr interval, it was demonstrated that mortality among those surviving an acute cardiac infarction was significantly higher among those who were single, divorced, separated or widowed [21]. A contributory cause to these differences might be that the emotional support a husband and wife give each other has a stress-reducing effect [ 1,211. Women tend to suffer cardiac infarction and sudden death lO-20yr later than men [22]. In older women the incidence of cardiovascular diseases seems to be related not only to age but also to the time when menstruation ceases [23]. On the whole, it would seem that women are less physiologically reactive than men. It is probable, however, that even women’s reactivity is affected by sociocultural factors. Since women are to an increasing extent taking up typical male occupations with their stress producing
Regional variations in cardiovascular mortality conditions, their reactivity would seem to be increasing and becoming more and more like men’s [24]. MODEL AND METHOD
Various social phenomena were studied in 91 local authority areas in Sweden and the data related to deaths from IHD. The analysis of how these different phenomena covaried with the IHD mortality rate was carried out in two stages. Firstly, the bivariate relationships (Pearson) between each of the phenomena and IHD mortality in men and women respectively were studied, and then a multiple regression analysis (stepwise variable selection) was carried out partly to discover hidden and apparent connections and partly to weigh the significance of the various social phenomena for regional variations in IHD. In all the multiple regression analyses the following parameters were used: for entrance to or removal from the model an F value > 4 (P < 0.05) were used. The design used in the investigation is presented in Fig. 1. The IHD figure for men and women respectively is age-standardized and covers the S-yr period 1979-1983. It refers to mortality in the 45-64 age group. The figures include everybody whose cause of
‘INDEPENDENT LABOUR
913
death was given as IHD during the period 1979-1983. Figure 1 shows which years are covered by the different factors and the statistical sources for each factors are specified. One problem is that the different ‘independent’ factors do not exactly cover the same period as the IHD mortality rate (1979-1983). As shown in Fig. 1, there are two factors that cover exactly the same period as the mortality rate namely; the unemployment rate and the divorce rate. For the other ‘independent’ factors the figures vary from 1980 to 1983. However, if the stability is high over time or if the proportions between the different communities are stable over time, the above mentioned problems with different time-periods can be neglected. One factor is probably less stable. namely ‘number of employees affected by bankruptcies’. The figures cover the period 1983 and there is an evident risk that the figures for a single year might give a wrong picture of the relationship between the factor and the dependent variable since it can be assumed that the stability over time is low. An important issue in cross-sectional studies is the problem with time-lag. In the normal case it takes time to develop ischemic heart disease. However, there is reason to believe that in the beginning of a given time period, for example a specific year, there
‘DEPENDENT
FACTORS’
MARKET
in Sweden
FACTORS’
CONDITIONS
Proportion unemployed in age groups 16-64 yearly average for the period 1979-l 983t Proportion of families with only one member gainfully employed in 1982’ Proportion of couples with no member gainfully employed in 1983’ Proportion of men in age group 16-24 gainfully employed in 1982t Proportion of women in age group 16-64 gainfully employed in 1982t Number of employees afffected by bankruptcies/1000 employees in 1983’ INCOME Average income from employment in 1982’ Proportion of men and women in different income groups in 1982’ SOCIOECONOMIC STRUCTURE Proportions in different socioeconomic groups as a percentage of the total population in age group 16-64 in 1980’ DEGREE OF POPULATION
DENSITY
Area’s degree of population density in 1980’ EARLY RETIREMENT Proportion retired early in age group 16-64
in 1982%
DIVORCE RATE Number divorced in relation to total population, average for the years 1979-l 983’ SINGLE-PERSON HOUSEHOLDS Single-person households as a percentage number of households’
of the total
‘Source: National Central Bureau of Statistics. tSource: National Labour Market Board. SSource: National Social Insurance Board.
Fig. I. Research model.
IHD mortality, men 1979-1983’
IHD mortality, women 1979-l
983’
BENGT ~TARRIN er al.
914 Table I Correlation
between different
characteristics in the local community and the IHD (ischemic men and women in age groups 45-64
heart disease) mortality
rate among
IHD mortality
Labour
market
Proportion: Unemployed in age group 16-64 Of families with only one member gainfully employed Of couples with no member gainfully employed Of employed men in age group 16-64 Of employed women in age group l&54 Employees affected by bankruptcies (number of employees affected by bankruptcies/i000
conditions
Socioeconomic
structure
Degree of population Divorce
density
rate
Single person households
Women
0.42*‘* 0.28”’ 0.31*** -0.32*** -0.34*** 0.14
0.26,. 0.15 0.14 -0.08 -0.12 0.03
-0.25.
-0.08
4%!?4
employees)
Average income from employment Proportion of men in different income groups: -39,000 Swedish crowns 40.000-79.000 80,000-I 19.000 I2O,OOa-I 59.000 l6wOOProportion of women in different income groups: -39,000 Swedish crowns 40,00&79,000 80,00&l 19,000 120,00&159,000 160.00&
Income
rate
Men 45-64
-0.04 0.30’” -0.20 -0.27’. -0.22’ 0.05 0.06 0.06 -0.23. -0.23.
Proportion in different socioeconomic groups as a percentage of the total population in age group l&64: Unskilled workers Skilled workers All workers Lower ranking white-collar workers Middle and upper ranking white-collar workers All white-collar workers All employers including self-employed Those at home plus part-time employed (less than I6 hr per/week) Early retired in age group 16-64 years
0.31*** -0.04 0.24. -0.23. -0.33*** -0.31*** 0.03 0.20 0.30***
0.01 0.13 0.09 -0.12 -0.15 -0.15 0.09 0.13 0.06
Degree of population
-0.14
-0.05
Number Proportion
divorced
density
m relation
IO the total population
-0.09
smgle person households
0.00
0.02
0.17
l**P < 0.001; l*P SC0.01; lP < 0.05.
are a group of people who are very close to the critical border to a critical level of manifest disease, and for example to die in ischemic heart disease. This might be caused by accumulated stress or by other circumstances. If the strain among those who are close to a critical level is increasing as a result of, for example, some critical life events the risk for dying in IHD will increase. But on the other hand if the critical life events had not occurred the risk for dying in IHD had decreased. RESULTS
The link between regional characteristics and IHD mortality among men and women respectively is shown in Table 1. It can be seen from the table that in areas with a higher male IHD mortality, total unemployment seems to be above average and the level of employment for both men and women below average. The male IHD mortality rate is also higher in areas where a greater proportion of the households have no or only one person in gainful employment. Male IHD mortality is higher in areas with a lower average income. More specifically, the figures reveal that, in these areas, there is a greater proportion of men with low incomes and a smaller proportion with high incomes.
Furthermore, areas with a smaller proportion of white-collar workers and a larger proportion of blue-collar workers have a higher male IHD mortality. The table also shows that areas with a higher male IHD mortality have a larger proportion of people who have taken or been forced into early retirement. The areas with a higher female mortality have a higher level of unemployment and fewer high-income earners. Multiple regression analyses were carried out separately for men and women. The results of the analysis for men are given in Table 2. It is apparent that only the variables ‘proportion unemployed’ and ‘proportion of unskilled workers’ are significantly related to the IHD mortality rate in men. The links between other factors and IHD mortality are explained by their relation to these two factors. Taken together these two factors account for about 22% of the Table 2. The effects of various factors on the mortality rate from ischemic heart disease in men in the 454 age prow (steowise regression analvsis) Factors Proportion Proportion
unemployed unskilled
Partial
R
0.37 0.22
0.42 0.31
Multiple R = 0.47, R2 = 0.22, P = 12.18775, signif F = 0.0000.
Regional variations in cardiovascular mortality in Sweden Table 3. The effects of various factors on the mortality rate from ischemic heart disease in women in the 45-64 age group (stepwise regression analysis) Factors Proportion
unemployed
Partial
R
0.26
0.26
Multiple R = 0.26, R* = 0.07. F = 6.55818, signif F = 0.0121.
variations in deaths from ischemic heart disease in men. The results of the regression analysis for women are given in Table 3. As can be seen, only the variable ‘proportion unemployed’ is significantly related to IHD mortality in women. The connection between income and IHD deaths revealed in Table 1 is explained by the link between income and unemployment. The unemployment factor accounts for about 7% of the variations in death from ischemic heart disease in women. DlSCUSSlON
Our analysis would, then, seem to suggest that, in the first place, it is the unemployment situation in the local community that is related to the IHD mortality rate, and that this is true for both men and women. It is in those areas with high unemployment that the highest levels of IHD deaths are to be found. Secondly-and this is only valid for men-mortality is linked to the proportion of unskilled workers. Since the study is based on figures for local authorities and not for individuals. there are a number of problems involved in drawing conclusions about the causal connection between the psychosocial environment and deaths at the individual level. It is typical of this kind of aggregate study that the concepts used often have an import that is different to their individual counterparts [25,26]. The aggregate concept ‘proportion unemployed’ probably expresses something different to and something more than the individual concept ‘being unemployed’. High unemployment in a local authority area tells us more than that a certain number of individuals are out of work. It is probable that the age structure of the population, communications, public service etc. are different from those in areas with low unemployment. The problem with aggregate studies like the present one is that there is a risk of drawing conclusions about connections at the individual level. Such a false conclusion here would be to say that those who are unemployed run a greater risk of dying from ischemic heart disease. When considering IHD deaths in men and women in the 45-64 age group two factors must be borne in mind: firstly, that this cause of death is 4-5 times more common in men than in women. In 1983 a little more than 3000 men in Sweden in the 45-64 age group died from ischemic heart disease. The figure for women was 657. Secondly, the results of the multiple regression analysis showed that only a small proportion of the variations in the female mortality rate could be ‘explained’ by the various social phenomena used in the study. The factors which, in the multiple regression analysis, proved to be statistically significant explained about 22% of the regional variations in men, but only 7% in women. This means that,
915
as regards mortality in women, most of the regional variations are-from a statistical viewpoint-unexplained. For this reason, it is perhaps true to say that the speculative reasoning that follows is less valid for theorizing about mortality in women than for that in men. We have shown that some areas have a markedly higher IHD mortality than others. One question we wish to raise is the following: are there certain characteristics, forces or stress factors-in the local community-which are of significance for the incidence of cardiovascular diseases? In order to prevent or delay the onset of the diseases and to be able to reduce the regional variations, it is of importance to identify these characteristics, forces or stress factors. From a psychosocial viewpoint then, it may be asked whether the regional variations in IHD mortality are linked to factors in the social environment in which people live. Before continuing our discussion, we shall make a brief reference to Dahlgren and Martensson’s comments on the concept of vulnerability [27]. The fact that something is vulnerable implies that it contains within itself the conditions necessary for a change in a negative direction: what is vulnerable can easily be damaged. Vulnerability is hidden and latent and not directly visible to man and is, therefore, sometimes difficult to foresee. When Dahlgren and Martensson speak of vulnerability in the local community, area or region, they mean the vulnerability that results from increased dependence on large scale economic and technical systems, i.e. external vulnerability, and the vulnerability in the system’s internal structural conditions and relations. That an area is vulnerable does not mean that it is already marked by social problems or other difficulties or that it will of necessity be so in the future. What it means is that there is greater risk of a negative development. Dahlgren and Martensson dwell on the link between vulnerability and social problems [27]. The characteristic feature of a social problem is that it is visible; it is the object of discussion and debate, and people are aware of its existence even if they may have different views about how to solve it. A social problem is a common concern, which involves norms, values and goals. Social problems thrive in a social system where there is an imbalance between people’s needs, activities and resources. Health problems may be social problems if they meet the requirements of visibility and if there is a general awareness of their existence. In the remainder of our discussion it is not, however, central whether the IHD mortality rate is seen as a social problem or not. The question we can now ask is whether regional variations in IHD may have anything to do with similar variations in the vulnerability of communities. In the introduction we took up two principal ways in which psychosocial conditions might influence the incidence of cardiovascular diseases. Further, we emphasized the need to formulate more complex models of how psychosocial conditions exert this influence. One such complex model has been formulated by Karasek, Russel and Theorell to reveal the link between working conditions and the incidence of cardiovascular and stress-related diseases [4]. The
916
BENGT STARRIN et al.
idea is that the lack of opportunity to influence the content and planning of one’s job coupled with great pressure at work creates negative stress. This negative stress may, in its turn, give rise to biological changes which might lead to illness. In Dahlgren and Martensson’s discussion of vulnerability similar ideas are applied to the local community as a whole but they are not related to the incidence of disease. They maintain that an increase in vulnerability within the local community may be described as a successive dissolution of links, overviews and control. A vulnerable community is a community where the opportunities for overview and control are strictly limited, where the inhabitants are no longer really able to determine and influence developments, a power which is in the hands of external decision-makers. Unemployment in a community or local authority area may be said to be both an indicator of vulnerability and a social problem. Depending on its level, it indicates shortcomings in the local community’s ability to influence developments and to meet people’s needs. It may also be said to be a problem in the sense that people recognize it as such, as a common concern to be solved [28]. When a community is hit by unemployment, the effect is much greater than the fact that more and more people are without gainful employment. For one thing, working conditions for those with jobs tend to become tougher. The work rate is increased and paradoxically enough so is overtime work [29]. As unemployment increases. people’s choices on the labour market become limited. It is more difficult to change jobs, at the same time as demands on the work environment are reduced [30]. When a small community or area is hit by unemployment, the social bonds between people tend to dissolve and there is considerable population movement. People have to move to get new jobs and this represents a further significant increase in the pressures on them. In the literature dealing with the link between the development of unemployment and the incidence of cardiovascular diseases one of the major questions discussed is whether variations in mortality are best explained by the increase and decrease of unemployment or by working conditions and other stressrelated factors. Eyer is of the opinion that bad working conditions, overtime work, dissension in the local community and the lack of solidarity probably explain the variations better than unemployment alone does [31). Individual studies show that both unemployment, the threat of unemployment [32-361, tense working conditions [4] and a lot of overtime work (371 can lead to stress-related illnesses. It has been shown that the combination of stressful work and the lack of opportunity to learn new things at work is related to the volume of institutional care for cardiac infarction [38]. In light of this, the link between the proportion of unskilled workers in the community and IHD mortality would seem to be understandable. The work carried out by the unskilled has characteristics which can create unfavourable stress, namely the combination of little control over one’s own work and great pressures. To increase our knowledge of the connection between unemployment and death from IHD, two conditions have to be studied more closely. Firstly, it
is of importance to examine the extent to which and the way in which high unemployment may be said to express a kind of general vulnerability within the local community. Our data and the discussion based on them would suggest that the indicator ‘proportion unemployed’ contains more information about the local community than the concept immediately refers to, namely, the number of unemployed related to the number employable. The fact that unemployment is high within a local community means that the local community is living under economically difficult circumstances. People are exposed to so-called economic stress. It may also be possible that the quality of care of sick individuals for some reason may be poorer in communities with high unemployment rates. Secondly, a closer examination should be made of the manner in which this potential vulnerability or economic stress affects people’s health and wellbeing, and of which groups of people are particularly exposed to it. It is reasonable to assume that two groups are in this difficult position: one being those people who have lost their jobs and the other those who are employed in industries where the threat of unemployment is great or where the chances of influencing one’s work situation is small. In both cases control over one’s own life is limited. If high unemployment is an expression of general vulnerability within the local community, it might be thought to affect people’s health by causing psychophysiological responses, psychopathological reactions and changes in behavioural patterns. This means that traditional risk factors such as smoking, hypertension and so on must be considered. In order to understand and explain these possible causal mechanisms, studies at the individual level are necessary. It is to be hoped that this study at the aggregate level which has attempted to describe the multiple links between macrofactors and IHD, will contribute to pave the way for such studies. REFERENCES 1. Ort-Gomer K., Perski A. and Theorell T. Psykosociala faktorer och hjlrt-och klrlsjukdom. En kunskapsiiversikt. Stockholm. H&o- och sjukvird under 90talet, sou 1984. 2. Jenkins C. D. I. Ischemic Heart Disease. The Strategy of Postponement (Edited by Tybjerg-Hansen A.. Schnohr P. and Rose G.), Vol. I. FADL, K(ipenhamn, 1977. 3. Kagan A. R. and Levi L. Health and EnvironmentPsychosocial SGmuli. A Reuiebx. Contribution to WHO document for the United Nations Conference on the Human Environment. World Health Organization, Geneva, 1972. 4. Karasek R. A., Russel R. S. and Theorell T. Physiology of stress and regeneration in job related cardio vascular illness. J. Human Stress 8, 2942, 1982. 5. Ort-Gomer K. Ischemic heart disease as a result of psychosocial processes. Sot. Sri. Med. 8, 3945, 1974. 6. gjiwall T. Ps)>kosomatisk Medicinhistorik. Definirioner och Framridvperspekrio (Edited bv Mellgren A.). Vol. I. Psykosomat&k medicin; Natur och K&r, Stockholm, 1980. 7. Mason I. W. Specificity in the organization of neuroendocrine respdnse p&files. In Fr&riers in Neurology and Neuroscience Research (Edited bv Seeman P. and Brown G.). University of T&onto, Ii)74.
Regional variations in cardiovascular mortality in Sweden 8. Larsson G. and Anderzen I. Appraisal. coping, catecholamine exretion and psychomotor performance during calm and stressful conditions, Scund. J. Sporrs Sci. 9, 47-51, 1987. 9. Puska P. and Mustaniemi H. Incidence and presentation of myocardial infarction in North Karelia, Finland. Acre med. scand. 197, 21 l-216, 1975. 10. Nyboe J.. Schnohr P. and Jensen G. Mortality by marital status, education and income in Copenhagen in 19761978. The Copenhagen City Heart Study, 1979. Il. Ort-Gomer K. Psychological stress and ischemic heart disease in Stockholm and New York. J. ps.rchosom. Res. 23, 165-173, 1979. 12. Spruit I. Unemployment and health in macro social analysis. Sot. Sci. Med. 16, 1903-1917, 1982. 13. Brenner H. Economic changes and heart disease mortality. Am. J. Publ. Hlrh 61(3), 606611, 1971. 14. Brenner H. Esrimaring lhe Social Costs of Nafional Economic Policy. U.S. Government Printing Office, Washington, D.C., 1976. 15. Brenner H. Mortality and the national economy: a review and the experiences of England and Wales, 19361976. The Lancer 15, 568-573, 1979. 16. Brenner H. Mortality and economic instability. Detailed analyses for Britain and comparative analyses for selected industrialized countries. Inr. J. Hlrh Serv. 13, 563-620, 1983a. 17. Brenner H. Importance of Economic Change in Swedish Health and Social Wellbeing 1950-1980. Socialstyrelsen, Stockholm, 1983b. 18. Nerbrand C., Aberg H.. Rosen M. and Tibblin G. Regionala skillnader i mortalitet i Mellansverige. Liikartidningen
46, 82. 40044008,
1985.
19. Somers A. R. Marital status, health and use of health services: an old relationship revisited. J. Am. med. Ass. 241, 1818-1822, 1979. 20. Lynch J. J. The Broken Heart: The Medical Consequences of Loneliness. Basic Books, New York, 1977. 21. Chandra V., Szklo M. et al. The impact of marital status on survival after an acute myocardial infarction: a population based study. Am. J. Epidem. 117, 32G325, 1983.
22. Dawber T. R. (Ed.) The Framingham Study. The Epidemiology Study. The Epidemiology of Atherosclerotic Diseuse. Harvard University Press. Cambridge, Mass.,
1980. 23. Kannel W. B. and Hjortland M. C. Menopause and risk of cardiovascular disease: the Framingham Study. Ann. intern. Med. 85, 447452.
1976.
24. Watkins L. and Eaker E. Population and demographic influences on reactivity. In Handbook of Srress, Reacriviry & Cardiovascular Disease (Edited by Mathews K. A.,
917
Weiss S. M.. Detre T., Dembrowski T. M., Faulkner B., Manuck S. B. and Williams R. B.). Wiley, New York, 1986. 25. Firebaug G. A rule for inferring individual relations from aggregate data. Am. Social. Rev. 43, 557-572, 1978. 26. Robinson W. S. Ecological correlations and the behavior of individuals. Am. Social. Rev. IS, 351-357, 1950. 27. Dahlgren L. and Martensson B. SGrbarher och Sjtilvtillir. Nord Refo. Oslo. 1983. 28. Mills C. W. Den Sociologiska Visionen. Prisma. Stock-
holm, 1971. B.. Lundberg B.. Angelow B. and Wall H. Unemployment, overtime work and work intensity. Paper presented at the Meeting on Unemplo_vmenr,
29. Starrin
Poverty and Qualify of Working Life-Innovative venrions IO Counteracr Damaging Healrh
InrerEflecrs,
Vienna, 12-14 May, 1987. WHO, Regional Office for Europe. ICP/HSR 818/29. 30. Starrin B., Lundberg B. and Angelow B. Tillsammans Blir vi Slarka. Arbersliishetens Eliinde. Motkamp. Prisma. Stockholm, 1985.
Vardag
och
31. Eyer J. Does unemployment cause the death rate peak in each business cycle. Inr. J. Hlrh Serv. 7, 625662, 1977. Arbersliisher och 32. Angeliiw B. Fiireragsnedliiggningar, Socialpsykologiska Srressreakrioner. Sociologiska insti-
tutionen, Lunds Universitet, 1986. 33. Brenner S.-O. and Levi L. Long-term unemployment among women in Sweden. Sot. Sci. Med. 25.2, 153-161, 1987. Socialmedicinsk 34. Janlert U. Arbelsliisher och Hiilsa-En Studie au Byggnadrarbetare i Luledregionen. Arbets-
marknadsdepartementet,
Stockholm, 1983.
35. Ametz B., Wasserman J., Petrini B., Brenner S.-O., Levi
L., Eneroth P., Salovaara H.. Hjelm R., Salovaara L., Theorell T. and Petterson I.-L. Immune function in unemployed women. Psychosom. Med. 49, 1, 3-12, 1987. Sociala och Hiilsomiissiga 36. Starrin B. Arbersloshefens Konsekvenser-En Lirrerrauriiversikt. Varmlands LIins Landsting, Sektionen for Samhlllsmedicin, Forskningsrapport nr 4, 1986. 37. Theorell T. and Rahe R. H. Behavior prior to myocardial infarction. In Psychological factors in Relarion IO the Onset of Mvocardial Infarction and for Some Metabolic Vari~bles~ A Pilor Study (Edited by Theorell
T.). Karolinska Institute, Stockholm, 1970. L.. Spetz C.-L. and Theorell T. Type of occupation and near-future hospitalization for myocardial infarction and some other diagnoses. Inr. J.
38. Alfredsson
Epidem.
14, 3, 378-388,
1985.