Variations in health status within and between socioeconomic strata.

OBJECTIVES To analyse the variability in health status within as well as between socioeconomic groups. What is the range of individual variability in the health effects of socioeconomic status? Is the adverse effect of lower socioeconomic status uniform across the entire distribution of health status? DESIGN Nationally representative telephone survey of the US population in 1996. SETTING 60 US metropolitan and rural areas. PARTICIPANTS 47 076 adult respondents to the community tracking study. MAIN OUTCOME MEASURES Self rated physical and mental health status, measured by the Short Form-12 instrument. RESULTS There is considerable variability in self rated health within socioeconomic strata and that variability increases in a step-wise fashion at each lower stratum of income. Most of the increased variability is accounted for by changes in the middle and lower (10th, 25th, and 50th centiles) rather than the upper (75th and 90th) portions of the distribution. A resilient subgroup of lower socioeconomic status people seems to maintain excellent self rated health throughout life, while a more vulnerable lower socioeconomic status group experiences rapid deterioration in health status as people reach middle age. CONCLUSIONS Within the population level social structuring of health there are differences in individual resilience and vulnerability that are amenable to further exploration and potential modification.