Study objective: Although it has frequently been suggested that income affects health, there is hardly any research in which this issue has been explored directly. The aim of this study was, firstly, to examine whether income is independently associated with health, secondly, to assess the extent to which this association reflects high levels of deprivation in low income groups, and thirdly, to examine which specific components of deprivation contribute most to the link between income and health. Health indicators used were the prevalence of chronic conditions, health complaints and less than "good" perceived general health.
Setting: Region in the south east of the Netherlands.
Participants: A population of 2567 men and women who participated in an oral interview, aged 15-74.
Design: Data were obtained from the baseline of a prospective cohort study aimed at the explanation of socioeconomic inequalities in health.
Results: Large inequalities in health by (equivalent) income after differences in other socioeconomic indicators had been controlled for were observed. For example, among those in the lowest income group the risk of bad perceived health was three times as high as among people in the highest income group. The prevalence of deprivation (basic, housing, social) increased with decreasing income to approximately 50-60% in the lowest income group. A substantial part of the increased health risks of the lowest income groups could statistically be accounted for by the higher prevalence of deprivation in these groups. The components that are likely to influence health indirectly, through a psychological or behavioural mechanism, accounted for most of the effect.
Conclusions: These analyses provide evidence to suggest that a low income has detrimental health effects through relative deprivation. Moreover, the results indicate an indirect link between deprivation and health problems involving psychological or behavioural factors.