After years of improving mortality rates in the United States, rates have increased, and between certain racial and ethnic groups the gap is widening depending on age.

Between 2009 and 2012, mortality rates, which were on the decline for most racial/ethnic groups, began to increase, and for very young and middle-aged people, the mortality rate gap between groups began to grow, according to a study from the UW Population Health Institute, led by Keith Gennuso, assistant scientist.

It was surprising to find that the U.S. has either ceased or reversed years of progress in reducing racial/ethnic mortality disparities across most age groups over the last decade, he said.

“It’s particularly worrisome that the trend in infants and children was largely being driven by increasing mortality rates in those with historically poorer health,” Gennuso said. “These populations have and continue to face societal barriers to good health.”

The purpose of the study was to examine premature mortality rates for people less than one year old to 74 years old and compare recent trends in racial/ethnic disparities across age groups. Data on more than 11 million deaths between 2007 and 2016 were obtained from the Centers for Disease Control and Prevention.

Critically, the data analysis showed relative disparities between racial/ethnic groups among infants were almost twice that of the other age groups in the study, and the gap that was decreasing at 6.5 percent per year may now be increasing.

Digging deeper, the findings revealed that the halting of progress in reducing black child mortality had a profound impact on the increase of racial/ethnic disparities. At 11 deaths per 1,000 births, the mortality rate for black infants remains the highest, more than twice that of white infants.

The article recently appeared in the American Journal of Preventive Medicine.

Mortality disparities by age groups were determined by calculating between-group variance, according to the study. Between-group variance is the summary of the total gap between mortality rates of Asian, American Indian/Alaska Native, black, Hispanic and white populations.

The findings in this study show that attention paid to overall mortality rates is important, but disparities between ages and racial/ethnic groups persist and appear to be growing, according to Gennuso.

“We are far from achieving the Healthy People 2020 goal to ‘achieve health equity, eliminate disparities, and improve the health of all groups,’” he said. “If the U.S. hopes to effectively address the recent trend of increasing disparities, it will be important for us to apply lessons learned from our years of progress and implement solutions that attend to root causes if we hope to regain what was lost in the decade to come.”

Support for this research project was provided in part by the Robert Wood Johnson Foundation and the Wisconsin Partnership Program. The views expressed here do not necessarily reflect the views of either party.