Effects of socio-economic status on mortality: separating the nearby from the farther away.

Socio-economic status effects on total and cause-specific mortality are studied using data on all 15.8 million inhabitants of the Netherlands in 1999. Two problems are addressed that often hamper this kind of research: the lack of reliable social status information at the individual level and the intermingling of individual and neighbourhood status effects. The first problem is dealt with by using socio-economic status information of the very close environment of the detailed postcode areas (average 41 inhabitants) in which one is living and the second one by combining this information with such area information at the much larger level of neighbourhoods (1500 inhabitants) or boroughs (6600 inhabitants). Clear and independent effects of socio-economic status at all three levels of aggregation are found on total mortality and for a majority of causes of death. In almost all cases, the effects are to the disadvantage of people living in the lowest status areas. The effects are generally strongest at the detailed postcode level and weakest at the borough level, suggesting greater importance of factors at the nearby or individual level than at the farther away level(s).