Has it always paid to be rich? Income and cause-specific mortality in southern Sweden 1905-2014.

Socio-economic differences in mortality are among the most pervasive characteristics of Western societies. While the mortality gradient by income is well established for the period after 1970, knowledge about the origins of this gradient is still rudimentary. We analyse the association between income and cause-specific adult mortality during the period 1905-2014 in an area of southern Sweden, using competing-risk hazard models with individual-level longitudinal data for over 2.2 million person-years and over 35,000 deaths. We find that the present-day income gradient in adult mortality emerged only in the period after the Second World War and did so for the leading causes of death and for men and women largely simultaneously.