Cause of death can’t explain lifespan gap between races

"If you could magically change everything and make it so blacks and whites died of exactly the same causes, that would have surprisingly little effect on the difference in lifespan variability," says Glenn Firebaugh. "About 87 percent of the overall difference would persist." (Credit: Tasha Chawner/Flickr)

Life expectancies for black people are shorter and more uncertain, on average, than those of whites, but the reason why may not be as clear as once thought.

Higher rates of certain kinds of death, such as murder, are often used to explain the lifespan variability, but new research shows that higher rates of other causes of deaths among young white people appear to offset this.


“We initially suspected that the greater variance in lifespan for blacks would be a result of differences in the causes of death, for instance, the higher homicide rates among blacks,” says Glenn Firebaugh, professor of sociology and demography at Penn State.

“But, as we looked closer, we saw that suicides and deaths due to drug poisoning—deaths that are more common among whites—offset the higher homicide rates for blacks.”

Black homicide rates account for about 38 percent of the greater variance for blacks. However, the higher rates of white suicide and death due to drug overdose nearly cancels out the homicide effect.

Taken all together, differences in causes of death account for only about 13 percent of the difference in lifespan variability between blacks and whites.

Target sex, not just race

“If you could magically change everything and make it so blacks and whites died of exactly the same causes, that would have surprisingly little effect on the difference in lifespan variability,” Firebaugh says. “About 87 percent of the overall difference would persist.”

In addition to behavioral reasons for lifespan uncertainty, researchers have also theorized that differences in medical treatment of and health prevention strategies for black and white patients may explain some of the difference in the variability of lifespan.

The researchers suggest that interventions to reduce this disparity may be more effective if they target sex, as well as race.

“With regard to policy, our results indicate the importance of sex-specific intervention to reduce racial disparities,” researchers write in the study, which appears in the journal Demographics.

“In the case of HIV/AIDS, for example, there is greater potential for significant reduction of the racial gap when men are targeted. The opposite is true for heart disease and diabetes, where interventions focused on women are more likely to narrow the gap.”

Lifespan uncertainty

Focusing on preventing specific causes of death, such as homicide and HIV/AIDS deaths, would help significantly cut the disparity. Eliminating the difference in deaths due to those two causes would cut the black-white disparity in lifespan variance by half, researchers say.

Lifespan uncertainty is important because it may have a ripple effect for people and society, Firebaugh says.

“This isn’t part of the study, of course, but the uncertainty in lifespan could lead to uncertainty about the future. One could imagine, for instance, that a consequence of people facing more uncertain lifespans would be that they change the way they plan, or don’t plan, for health or education, for example, or for investing in retirement.”

The researchers used information from the National Center for Health Statistics 2010 Multiple Cause of Death data archive. Claudia Nau, a postdoctoral fellow in public health at Johns Hopkins University contributed to the study.

The Eunice Kennedy Shriver National Institute of Child Health and Human Development supported the work.

Source: Penn State