The U.S. has the worst child mortality rate among a group of 20 wealthy democracies in the Organization for Economic Co-operation and Development. Westwood One Correspondent Ciera Crawford reports that’s according to a study published in the journal Health Affairs on Monday.

The study examined child mortality rates between 1961 and 2010 in the U.S. and comparable nations in the OECD, a group of 35 countries, founded to improve economic development and social well-being around the world. It found that mortality rates were not evenly distributed.

“This study should alarm everyone. The U.S. is the most dangerous of wealthy, democratic countries in the world for children,” said Dr. Ashish Thakrar, lead author of the study and an internal medicine resident at Johns Hopkins Hospital and Health System in Baltimore. “We were surprised by how far the U.S. has fallen behind other wealthy countries,” he said. “Across all ages and in both sexes, children have been dying more often in the U.S. than in similar countries since the 1980s.”

Some of the factors driving America’s child mortality rate were related to infant deaths, automobile accidents and firearm assaults, according to the study. Researchers analyzed data on mortality rates for children up to age 19 in the U.S., Australia, Austria, Belgium, Canada, Denmark, Finland, France, Germany, Iceland, Ireland, Italy, Japan, the Netherlands, New Zealand, Norway, Spain, Sweden, Switzerland and the United Kingdom. The data, which dated from 1961 to 2010, came from the Human Mortality Database and the World Health Organization’s Mortality Database. The researchers found that childhood mortality rates declined gradually from 1961 to 2010 for the U.S. and the 19 other nations, which was a big success for public health. Yet the U.S. rate fell at a slower pace than the other nations over those 50 years. Specifically, during the decade from 2001 to 2010, the researchers found that the mortality rate in the United States was about 75% higher for infants and about 50% higher for children ages 1 to 19 than the average rate calculated for all of the countries in the study. During that decade, other countries with infant mortality rates also above the overall average included Switzerland, New Zealand, the Netherlands, Ireland, the United Kingdom, Canada and Australia.

Those with child mortality rates above the overall average were Ireland, Austria and Canada.