Income Gap is a Matter of Childhood Life and Death

ROCKVILLE, Md., Aug. 1 -- Although there was an overall drop in childhood death rates from all causes from 1969 through 2000, most of the declines occurred among children from upper income brackets.

The relative overall disparity in child mortality across socioeconomic quintiles widened from 25% in 1969-1970 to 34% in 1988-1990 and 43% in 1998-2000," wrote Gopal K. Singh, Ph.D., M.S., M.Sc., and Michael D. Kogan, Ph.D., of the Health Resources and Services Administration in an early online release from the Sept. issue of the American Journal of Public Health.

The authors analyzed data from the National Vital Statistics System and the U.S. census to determine socioeconomic patterns in childhood mortality.

"We used a factor-based deprivation index that consisted of 17 census-based social indicators, which may be viewed as broadly representative of educational opportunities, labor force skills, and economic and housing conditions," they wrote.

They used selected indicators of education, occupation, wealth, income distribution, unemployment rate, poverty rate, and housing quality to create their index. They also created regression models and inequality indices to evaluate time-related disparities among socioeconomic groups.

They found that mortality among 1- to 14-year-olds declined over time in all income quintiles, by average annual rates from 1969 through 2000 of 2.32% for the most economically deprived quintile (Q1), to 2.50%, 2.60%, and 2.86% for quintiles 2 through 4, and to 3.11% for the most privileged quintile 5.

But over time the gap between the poorest and richest widened substantially. In 1969-1971, the most deprived children had a relative risk for death of 1.52 (95% confidence interval 1.48 to 1.55) compared with kids in the most well-off families. By the1998-2000 interval, however, the relative risk of death for the poorest vs. richest children was 1.86 (95% CI, 1.80 to 1.92).

The growing economic/mortality gap occurred among both whites and blacks, but the income divide was more evident and more consistent among whites, the investigators noted.

When they looked at specific causes of death, they found that:

• From 1969 through 1971, children in the most deprived socioeconomic quintile had a 52% higher risk for all-cause mortality compared with the most well-heeled children. This gap grew to 86% during the 1998-2000 interval.
• Birth defects, which accounted for a 13% higher relative risk of death for the most deprived in 1969-1971, accounted for a 44% greater risk in 1998-2000.
• Similarly, while poorer children in 1969-1971 had a 69% higher relative risk for unintentional injury and a 76% higher risk for death from homicide, by 1998-2000 the differential in those relative risks had grown to 177% and 159%, respectively.

"Dramatic reductions in mortality among children in all socioeconomic quintiles represent a major public health success," the authors wrote.

"However," they said, "children in higher socioeconomic quintiles experienced much larger declines in overall, injury, and natural-cause mortality than did those in more deprived socioecnomic quintiles, which contributed to the widening socioeconomic gap in mortality."

The authors noted that the disparities they identified may underestimate the actual differences among socioeconomic groups, because they constructed their deprivation indices using data at the county rather than town or city level.