American Indian and Alaska Native families are much more likely to have an infant die suddenly and unexpectedly, and that risk has remained higher than in other ethnic groups since public health efforts were launched to prevent sudden infant death syndrome in the 1990s. African-American babies also face a higher risk, a study finds.
American Indians and Alaska Natives had a rate of 177.6 sudden unexplained infant deaths per 100,000 live births in 2013 (down from 237.5 per 100,000 in 1995) compared with 172.4 for non-Hispanic blacks (down from 203), 84.5 for non-Hispanic whites (down from 93), 49.3 for Hispanics (down from 62.7) and 28.3 for Asians and Pacific Islanders (down from 59.3). The declines were statistically significant only among non-Hispanic blacks, Hispanics and Asians/Pacific Islanders.
"There are still significant gaps and disparities between races and ethnicities," says Lori Feldman-Winter, a professor of pediatrics at Cooper University Health Care in Camden, N.J., who wasn't involved with this study but was a co-author of the most recent sleep guidelines from the American Academy of Pediatrics, released in the fall.
Overall rates of sudden unexpected infant death, which includes sudden infant death syndrome as well as accidental suffocation or strangulation in bed and other unexplained deaths, declined sharply in the five or so years after a national campaign was launched in 1994 to encourage caregivers to put babies to sleep on their backs. But the rates have not declined since 2000. Researchers at the Centers for Disease Control and Prevention wanted to know whether those changes were uniform across racial and ethnic groups.
"We had the overall picture, but no one had really taken a close look at what was happening within that," says Sharyn Parks, an epidemiologist at the CDC and an author of the study, published Monday in Pediatrics.
The reasons behind those changes and why rates among American Indians/Alaskan Natives and African-Americans remain so much higher than those of non-Hispanic whites, Hispanics and Asians/Pacific Islanders aren't known.
One important consideration is that the study didn't control for socioeconomic or other factors, such as prenatal or postnatal exposure to alcohol or tobacco and breast-feeding patterns. So disparities or changes might be influenced by other factors besides race and ethnicity, such as the differences in the prevalence of prenatal care, says Parks.
It's also not possible to determine whether the public health campaign on safe sleeping played a role in reducing death rates.
An editorial accompanying the study notes that while non-Hispanic black infants saw death rates decline significantly, separate research has shown that African-Americans are also less likely than other racial and ethnic groups to embrace the safe sleeping recommendations. That suggests something else may have helped drive the improvement in that group, says Richard Goldstein, an author of the editorial and a pediatrician at Dana-Farber Cancer Institute and Boston Children's Hospital. He says it's important to consider all the factors that might have helped improve survival, including advances in care for premature infants and a decline in the rate of women younger than 20 having babies. Both preemies and infants born to young mothers are at higher risk of sudden unexplained death.
Goldstein's own research looks at whether an underlying vulnerability might account for some sudden unexplained infant deaths and possibly other infant deaths that occur soon before and after birth. For example, he and colleagues showed that sudden unexplained deaths in infancy and later in childhood were both associated with a brain abnormality usually seen in temporal lobe epilepsy. It's not clear whether the abnormality caused the deaths, though.
Parks says research into potential biological factors, including brain abnormalities and genetic variations, is important. She also says it's essential to do more research on the differences in sleeping behaviors, such as bed sharing, between ethnic and racial groups and how to change those behaviors.
"Something continues to hamper the ability to get the message out or for folks in different cultures to receive the message," says Feldman-Winter.
Socioeconomic status can be a big factor, she says, noting that while the AAP recommends against bed sharing, some families may not be able to afford a crib.
"People should do whatever they can to reduce the risk," says Goldstein.
Katherine Hobson is a freelance health and science writer based in Brooklyn, N.Y. She's on Twitter: @katherinehobson.