from the Journal of Epidemiology and Community Health, Vol 56 (1)

Socioeconomic context in area of living and risk of myocardial infarction:
results from Stockholm
Heart Epidemiology Program (SHEEP)

M K



ölegård Stjärne1, F Diderichsen1, C Reuterwall2 and J Hallqvist1 for
the Sheep Study Group

1 Division of Social Medicine, Department of Public Health Sciences, Karolinska
Institutet, Stockholm, Sweden
2 Division of Epidemiology, Institute of Environmental Medicine, Stockholm
County Council, Stockholm, Sweden

Correspondence to:
Maria Kölegård Stjärne, Karolinska Institutet, Department of Public Health
Sciences, Division of Social Medicine, SE-171 76 Stockholm,
Sweden;
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http://jech.bmjjournals.com/cgi/content/abstract/56/1/29

Study objective: To analyse if socioeconomic characteristics in area of living
affect the risk of myocardial infarction in a Swedish
urban population, and to evaluate to what extent the contextual effect is
confounded by the individual exposures.

Design: A population based case-referent study (SHEEP).

Setting: Cases (n=1631) were all incident first events of myocardial infarction
during 1992-1994. The study base included all
Swedish citizens aged 45-70 years, living in Stockholm metropolitan area during
these years. The social context of all
metropolitan parishes (n=89) was determined by routine statistics on 21
socioeconomic indicators. A factor analysis of the
socioeconomic indicators resulted in three dimensions of socioeconomic
deprivation, which were analysed separately as three
different contextual exposures.

Main results: The main characteristics of the extracted factors were; class
structure, social exclusion and poverty. Among men,
there were increased relative risks of similar magnitudes (1.28 to 1.33) in the
more deprived areas according to all three
dimensions of the socioeconomic context. However, when adjusting for individual
exposures, the poverty factor had the
strongest contextual impact. The contextual effects among women showed a
different pattern. In comparison with women living
the most affluent areas according to the class structure index, women in the
rest of Stockholm metropolitan area had nearly
70% higher risk of myocardial infarction after adjustment for individual social
exposures.

Conclusions: The results suggest that the socioeconomic context in area of
living increases the risk of myocardial infarction. The
increased risk in only partially explained by individual social factors (the
compositional effect).