The European Journal of Public Health Advance Access originally published online on August 9, 2006
The European Journal of Public Health 2007 17(2):139-144; doi:10.1093/eurpub/ckl119
Health inequalities |
Are manual workers at higher risk of death than non-manual employees when living in Swedish municipalities with higher income inequality?
Göran Henriksson1, Peter Allebeck2, Gunilla Ringbäck Weitoft3 and Dag Thelle4
1 Department of Social Medicine, Göteborg University SE 405 30 Göteborg, Sweden
2 Department of Social Medicine, Karolinska Institute SE 171 76 Stockholm, Sweden
3 Centre for Epidemiology, National Board of Health and Welfare SE 10630 Stockholm, Sweden
4 The Cardiovascular Institute, Sahlgrenska universitetssjukhuset Göteborg University, SE 413 45 Göteborg , Sweden
Correspondence: Göran Henriksson, Department of Social Medicine, Göteborg University, Box 453, SE 405 30 Göteborg, Sweden, tel: +46 31 773 68 61, fax: +46 31 16 28 47, e-mail: goran.henriksson{at}socmed.gu.se
Received November 23, 2005 , accepted May 2, 2006
Objectives: To test the hypothesis that manual workers are at higher risk of death than are non-manual employees when living in municipalities with higher income inequality. Design: Hierarchical regression was used for the analysis were individuals were nested within municipalities according to the 1990 Swedish census. The outcome was all-cause mortality 1992–1998. The income measure at the individual level was disposable family income weighted against composition of family; the income inequality measure used at the municipality level was the Gini coefficient. Participants: The study population consisted of 1 578 186 people aged 40–64 years in the 1990 Swedish census, who were being reported as unskilled or skilled manual workers, lower-, intermediate-, or high-level non-manual employees. Results: There was no significant association between income inequality at the municipality level and risk of death, but an expected gradient with unskilled manual workers having the highest risk and high-level non-manual employees having the lowest. However, in the interaction models the relative risk (RR) of death for high-level non-manual employees was decreasing with increasing income inequality (RR = 0.77; 95% CI, 0.63–0.93), whereas the corresponding risk for unskilled manual workers increased with increasing income inequality (RR = 1.24; 95% CI, 1.06–1.46). The RRs for skilled manual, low- and medium- level non-manual employees were not significant. Controlling for income at the individual level did not substantially alter these findings, neither did potential confounders at the municipality level. Conclusions: The findings suggest that there could be a differential impact from income inequality on risk of death, dependent on individuals' social position.
Keywords: attempted suicide, income inequality, myocardial infarction, Sweden, socio-economic position