The contribution of education, social class and economic activity to the income-mortality association in alcohol-related and other mortality in Finland in 1988-2012

Abstract

Aims: First, to quantify trends in the contribution of alcohol-related mortality to mortality disparity in Finland by income quintiles. Secondly, to estimate the degree to which education, social class and economic activity explain the income-mortality association in alcohol-related and other mortality in four periods within 1988-2012.

Design: Register-based longitudinal study using an 11% random sample of Finnish residents linked to socio-economic and mortality data in 1988-2012 augmented with an 80% sample of all deaths during 1988-2007. Mortality rates and discrete time survival regression models were used to assess the income-mortality association following adjustment for covariates in 6-year periods after baseline years of 1988, 1994, 2001, and 2007.

Setting: Finland.

Participants: Individuals aged 35-64 years at baselines. For the four study periods for men/women, the final data set comprised, respectively, 26,360/12,825, 22,561/11,423, 20,342/11,319 and 2651/1514 deaths attributable to other causes and 7517/1217, 8199/1450, 9807/2116, 1431/318 deaths attributable to alcohol-related causes.

Measurements: Alcohol-related deaths were analysed with household income, education, social class and economic activity as covariates.

Findings: The income disparity in mortality originated increasingly from alcohol-related causes of death, in the lowest quintile the contribution increasing from 28 to 49% among men and from 11 to 28% among women between periods 1988-93 and 2007-12. Among men, socio-economic characteristics attenuated the excess mortality during each study period in the lowest income quintile by 51-62% in alcohol-related and other causes. Among women, in the lowest quintile the attenuation was 47-76% in other causes, but there was a decreasing tendency in the proportion explained by the covariates in alcohol-related mortality.

Conclusions: The income disparity in mortality among working-age Finns originates increasingly from alcohol-related causes of death. Roughly half the excess mortality in the lowest income quintile during 2007-12 is explained by the covariates of household income, education, social class and economic activity.

Keywords: Alcohol; disparity; income; mortality.