A clear social class gradient in mortality has been consistently reported among western populations. However, in the early 1980s in Finland, no major socioeconomic differences in mortality were found among people with diabetes. The present study examines whether this exceptional finding persisted in the 1990s.
All residents of Finland aged 30 to 74 in the 1980 and 1990 population censuses were classified as diabetic or non-diabetic according to entitlement to reimbursement for diabetes medication. The patient's age at onset of the disease was used as a proxy for diabetes type. All diabetic and non-diabetic persons were followed up for mortality in 1981-1985 and 1991-1996. Age-adjusted relative death rates were obtained from Poisson regression models.
From the early 1980s to the early 1990s marked socioeconomic mortality disparities favouring the better-off emerged among diabetic people. The increase in socioeconomic mortality differences from 1981-1985 to 1991-1996 was mainly due to divergence in deaths from diabetes, which contributed 52% of the increase in mortality disparity among women and 35% among men, and from cardiovascular diseases, whose contribution was 21% for women and 25% for men.
From the early 1980s to the 1990s in Finland a clear socioeconomic gradient in mortality emerged in every age group of diabetic people. This was largely due to a much worse development among blue-collar than white-collar workers in deaths from diabetes and cardiovascular diseases.