http://www.cna-nurses.ca/CNA/documents/pdf/publications/BG8_Social_Determinants_e.pdf

What’s the issue?
In all countries, it is well-established that poorer people have
substantially shorter life expectancies andmore illnesses than the rich.
This phenomenon has been observed since at least the nineteenth century
when Chadwick (1965) investigated the health of the working classes in
Victorian England.

Two contemporary British studies have been very influential in their
documentation of the relationship between socioeconomic factors and health
status. The Whitehall civil service study compared the health status of
individuals over time with their position in a well-defined job hierarchy.
Those lower in the hierarchy experienced three times the risk of death from
heart disease, stroke, cancer, gastrointestinal disease, accident and
suicide compared with those at the top of the hierarchy. These differences
could not be explained by differences in medical care... SNIP