In one year alone, over 4,500 children in the United States were hospitalized due to child abuse, and 300 of them died of their injuries, Yale School of Medicine researchers report in a new study. The findings are published in the March 2012 issue of Pediatrics (published online Feb. 6).

Several measures have been used to track the national occurrence of child abuse, including data from Child Protective Services. But until now none quantified the severity of the abuse or whether the child was hospitalized as a result.

Led by John M. Leventhal, M.D., professor of pediatrics and medical director of the Child Abuse and Child Abuse Prevention Programs at Yale-New Haven Children's Hospital, the researchers used the 2006 Kids' Inpatient Database (KID) to estimate the incidence of hospitalizations due to serious physical abuse among children younger than 18 years. KID was prepared by the Healthcare Cost and Utilization Project, part of the Agency for Healthcare Research and Quality.

They found 4,569 children were hospitalized in the U.S. in 2006 due to serious abuse; 300 of these children died. Children in their first year of life were at highest risk, of being hospitalized, making up 58.2 per 100,000 children in this age group.

Serious abuse was defined as any child who was admitted to the hospital with an injury that was coded as abuse. Such children included a 3-month-old with multiple bruises due to abuse and a 3-month-old with life-threatening abusive head trauma. The definition did not include children admitted with suspicious injuries who were eventually diagnosed as having non-abusive injuries.

"These numbers are higher than the rate of sudden infant death syndrome (about 50, per 100,000 births), which is alarming," said Leventhal, who also notes that children covered by Medicaid had rates of serious abuse about six times higher than those not on Medicaid. "This speaks to the importance of poverty as a risk factor for serious abuse."

The estimated national cost for the hospitalizations due to serious abusive injuries was $73.8 million. "These data should be useful in examining trends over time and in studying the effects of large-scale prevention programs," said Leventhal.