Racial differences in life expectancy vary substantially across U.S. states

Racial differences in life expectancy have declined nationally but still vary substantially across U.S. states, according to a new study by McGill University researchers. The findings, published in the journal Health Affairs, suggest that state policies could play a key role in further reducing racial differences in mortality. The researchers calculated annual state-specific life expectancies for blacks and whites from 1990 to 2009 and found that progress was uneven across states during the past two decades.

"Prior studies in the United States have shown that, for the nation as a whole, the difference in life expectancy between blacks and whites has declined over the past two decades", says Sam Harper, of the Department of Epidemiology, Biostatistics & Occupational Health in the Faculty of Medicine. "What was not known was how individual states have fared in reducing this gap."

Harper and his colleagues assessed for the first time how U.S. states have performed over the past two decades. "Some states have clearly done much better than others. For example, we found large improvements in New York, but the gap actually increased in Wisconsin. More generally, we found that states in the Northeast made considerably more progress than states in the West for both men and women, but even within regions of the U.S. there was a lot of heterogeneity among states," says Harper, the study's first author.

The team used novel statistical techniques coupled with data from death certificates and estimates of the population in each U.S. state to calculate life expectancies, even for some states with small black populations.

"For both men and women, New York state made far and away the largest contribution to reducing the national black-white gap," says Harper. "However, other states with comparatively large black populations like California and Texas kept the national gap from closing more than it did. We know from prior work that fewer deaths from HIV/AIDS and homicide played a big role in New York's life expectancy improvements. Our results suggest that other states may benefit from a detailed study of how and why the gap decreased so much in New York."

Black-white differences in life expectancy are a longstanding source of public health concern in the United States, and are considered indicative of deeper social inequities in society.

"We want to know how to reduce these differences. Given that many social and health policies are implemented at the state level, looking at how specific states have fared can provide important clues for addressing these health inequalities. Our results should be of particular interest to state public health officials focused on reducing racial differences in health."