The relationship between social stratification and all-cause mortality among children in the United States: 1968-1992

Background. US childhood poverty rates have increased for most of the past 2 decades. Although overall mortality among children has apparently fallen during this interval, these aggregate mortality rates may hide a disproportionate burden imposed on the least advantaged. This study assessed the impact of social stratification on long-term US childhood mortality rates and examined the temporal relationship between mortality attributable to social stratification and childhood poverty rates. Methods. Using US childhood mortality data obtained from the Compressed Mortality File (National Center for Health Statistics) and a county-level measure of social stratification (residential telephone availability), I evaluated the impact of social stratification on longterm trends (1968-1992) in age-adjusted mortality and compared the resulting attributable proportions to trends in childhood poverty rates. Results. Between 1968 and 1987 the proportion of US childhood deaths attributable to social stratification decreased from .22 to .17. Subsequently, it increased to .24 in 1992, despite continuous declines in overall childhood mortality rates. These proportions correlated strongly with earlier childhood poverty rates, taking into account an apparent 9-year lag. Among black children comparable trends were not observed, although throughout this time period their mortality rates were far higher than among the rest of the population and declined more slowly. Conclusions. Despite declining childhood mortality rates between 1968 and 1992, children living in the least advantaged counties continued to die at higher rates than those living in the most advantaged counties. This differential worsened considerably after 1987, and by 1992 had a substantive impact on US life expectancy at birth, resulting in perhaps the most significant (in terms of years of life lost) reversal in the health of the US public in the 20th century.