Income differences in mortality: a register-based follow-up study of three million men and women

The mainly linear nature of the relationship and the strong attenuation after adjustment for other socioeconomic factors and economic activity status, and the age pattern of the relationship indicate that a large part of the relationship is unlikely to be due to direct causal effects of poverty and material hardship. Rather, income seems to be related to accumulation of factors that increase mortality over the whole range of incomes.