Socioeconomic status, status inconsistency and risk of ischaemic heart disease:: a prospective study among members of a statutory health insurance company

Background: Inconsistency in social status and its impact on health have been a focus of research 30 - 40 years ago. Yet, there is little recent information on it's association with ischaemic heart disease (IHD) morbidity and IHD is still defined as one of the major health problems in socioeconomically developed societies. Methods: A secondary analysis of prospective historical data from 68 805 male and female members of a statutory German health insurance company aged 25 - 65 years was conducted. Data included information on sociodemographic variables, social status indicators ( education, occupational grade and income) and hospital admissions because of IHD. Results: Findings from Cox regression analysis showed an increased risk for IHD in the group with the highest educational level, whereas the lowest occupational and income groups had the highest hazard ratio (HR). Further analysis revealed that after adjustment for income status inconsistency ( defined by the combination of higher educational level with lower occupational status) accounts for increased risk of IHD ( HR for men, 3.14 and for women, 3.63). An association of similar strength was observed regarding high education/ low income in women ( HR 3.53). The combination of low education with high income reduced the risk among men ( HR 0.29). No respective findings were observed concerning occupational group and income. Conclusions: Status inconsistency is associated with the risk of IHD as well as single traditional indicators of socioeconomic position. Information on status inconsistency should be measured in addition to single indicators of socioeconomic status to achieve a more appropriate estimation of the risk of IHD.