Socioeconomic status and trends in risk factors for cardiovascular diseases in the Danish MONICA population, 1982-1992

STUDY OBJECTIVE—The decline in cardiovascular mortality in Denmark during the 1980s has been greatest in the highest socioeconomic groups of the population. This study examines whether the increased social inequality in cardiovascular mortality has been accompanied by a different trend in cardiovascular risk factors in different educational groups.
DESIGN—Data from three cross sectional WHO MONICA surveys conducted in 1982-84, 1987, and 1991-92, were analysed to estimate trends in biological (weight, height, body mass index, blood pressure, and serum lipids) and behavioural (smoking, physical activity during leisure, and eating habits) risk factors in relation to educational status.
SETTING—County of Copenhagen, Denmark.
PARTICIPANTS—6695 Danish men and women of ages 30, 40, 50, and 60( )years.
MAIN RESULTS—The prevalence of smoking and heavy smoking decreased during the study but only in the most educated groups. In fact, the prevalence of heavy smoking increased in the least educated women. There was no significant interaction for the remaining biological and behavioural risk factors between time of examination and educational level, indicating that the trend was the same in the different educational groups. However, a summary index based on seven cardiovascular risk factors improved, and this development was only seen in the most educated men and women.
CONCLUSION—The difference between educational groups in prevalence of smoking increased during the 1980s, and this accounted for widening of an existing social difference in the total cardiovascular risk.


Keywords: cardiovascular risk factors; socioeconomic status; time trend

Social distribution of cardiovascular disease risk factors: change among men in England 1984-1993

OBJECTIVE—To investigate change in the social distribution of some of the main risk factors for cardiovascular disease in men in England during a period when inequality in cardiovascular disease mortality widened
DESIGN—Age standardised comparison of the social distribution of seven known risk factors for cardiovascular disease (body mass index, waist to hip ratio, systolic and diastolic blood pressure, consumption of fresh green vegetables, leisure time exercise, cigarette smoking and levels of social support) in two large cross sectional representative samples of the English population.
SUBJECTS—Men aged 20-64 years in the 1984 Health and Lifestyle Survey (excluding Scotland and Wales) first sweep and the 1993 Health Survey for England.
MAIN OUTCOME MEASURES—Mean values of continuous variables; age adjusted proportions of categorical variables; change in the relative index of inequality for each risk factor.
RESULTS—The overall prevalence of cardiovascular disease risk factors improved during the period in which cardiovascular disease mortality was falling. The social distribution of cardiovascular disease risk factors, in contrast, did not become more extreme. Increases in the relative index of inequality for angina from 1.75 to 1.86,( )for eating vegetables less than once a day from 1.76 in 1984 to 1.96 in 1993, and an apparently larger increase in inequality of social support, from 1.92 to 2.53 were not statistically significant. In most cases the degree of inequality in risk factors tended to narrow non-significantly: for example the relative index of inequality fell from 5.02 in 1984 to 3.07 in 1993 for systolic blood pressure, from 5.60 to 4.29 for current smoking and from 6.24 to 4.19 for eating other than wholemeal bread as the main form of bread in the diet. The two statistically significant changes in inequality were in the direction of narrowing inequality: from a relative index of inequality of 2.12 to 0.90 for diastolic blood pressure (p<0.01) and from 19.3 to 0.87 (p<0.01) for psychological distress as indicated by the General Health Questionnaire.
CONCLUSIONS—Healthier lifestyle options have not been adopted at a significantly faster rate by middle class than working class people over this time period. At the population level the change in risk factors is consistent with falling cardiovascular mortality. The change in the social distribution of risk factors within the population, however, shows little or no relation to the pattern of widening inequality in cardiovascular mortality. This may be because the effect is lagged, or because the adoption of healthier behaviour confers greater benefits on those in higher socioeconomic status groups.


Keywords: cardiovascular diseas

Excess mortality from avoidable and non-avoidable causes in men of low socioeconomic status: a prospective study in Korea

STUDY OBJECTIVE—The objective of this study was to evaluate the magnitude and contributory factors of socioeconomic differentials in mortality in a cohort of Korean male civil servants.
DESIGN—A prospective observational study of male civil servants followed up for five years after baseline measurement.
SETTING—All civil service offices in Korea.
PARTICIPANTS AND MEASUREMENTS—The study was conducted on 759 665 Korean male public servants aged 30-64 at baseline examination in 1992. The grade of monthly salary of these participants divided into four groups, a proxy indicator of socioeconomic status (SES), was the main predictive variable. Mortality of the participants was followed up from 1992( )to 1996. The causes of deaths were categorised into four groups according to the medical amenability: avoidable, partly avoidable, non-avoidable, and external causes of death. The risk of mortality associated with SES was estimated using the Cox proportional hazard model.
MAIN RESULTS—Lowest SES group had significantly higher risk of mortality from most causes compared with the highest SES group in the order of external cause (relative risk (RR): 2.26), avoidable (RR: 1.65), all cause (RR: 1.59), and non-avoidable mortality (RR: 1.54). With the adjustment of known risk factors, significantly higher risks of mortality in lowest SES group were attenuated but persisted. Looking at the deaths from partly avoidable causes, significantly higher risks of mortality in the lowest SES group was observed from cerebrovascular disease but not from coronary heart disease.
CONCLUSIONS—Socioeconomic differentials in non-avoidable as well as avoidable mortality, persisting even under the control of risk factors, suggest that mortality is influenced not only by the quality of health care and different distribution of risk factors but also by other aspects of SES that are yet unknown.


What is the "golden standard" for assessing population-based interventions?—problems of dilution bias

OBJECTIVES—To identify different types of dilution bias in population-based interventions and to suggest measures for handling these methodological problems.
DESIGN—Literature review plus analysis of data from a population-based intervention against cardiovascular disease in a Swedish municipality.
MAIN RESULTS—The effects of an intervention on mortality and morbidity were much more diluted by non-intervening factors, dissemination to areas outside the intervention area, social diffusion, population mobility and time than by using intermediate outcome measures.
CONCLUSIONS—Theoretically, changes in scientifically well documented risk factors, for example, intermediate outcome measures, should be preferred to using morbidity or mortality as outcome measures.


Keywords: population-based intervention