While child protection agencies have found a dramatic drop in physical child abuse cases over the past decade, a new study shows that the number of hospitalizations for serious injuries resulting from abuse has actually increased.

Data compiled by the National Child Abuse and Neglect Data System, or NCANDS, which draws from files kept by child protective services agencies in the U.S., has shown a 55 percent decrease in total substantiated cases of physical abuse of children from 1992 to 2009.

But Yale researchers John M. Leventhal and Julie R. Gaither found that the number of children hospitalized for serious injuries resulting from child abuse actually increased by 5 percent over that same time period, with 54 percent of these severe abuse cases involving children less than 1 year of age, according to the paper.

Leventhal and Gaither published their results today in the journal Pediatrics.

The researchers’ numbers, culled from hospital discharge data, clearly show a statisticlly significant increase in hospitalizations for severe injuries among victims of child abuse. Less obvious is the explanation for the seemingly contradictory picture their results paint in contrast to the dramatic drop in physical abuse found by NCANDS.

In a phone interview, Leventhal said “there’s no way to cross-validate” cases to see if some of the serious hospitalization cases aren’t being picked up by CPS agencies.

Furthermore, the Yale researchers’ findings and the downward trend seen by NCANDS aren’t necessarily contradictory.

“We may be looking at different parts of the phenomenon. Maybe overall, there’s less physical abuse, but for extreme cases, things haven’t changed,” Leventhal said.

This seems plausible, since the NCANDS data includes all cases of physical abuse, regardless of how severe the abuse was or how old the child was at the time, according to the paper.

However, there may be another possible explanation behind the discrepancy. Leventhal speculated that the way that various agencies process child abuse cases may have changed over the 12-year time period examined by their study.

Next, Leventhal and other researchers plan to dig deeper into hospitalization data, breaking it down by injury type to see whether there are any visible trends or patterns.

Regardless of what further dissecting hospital data can yield, the key question, of course, is prevention, according to Leventhal.

“What kinds of messages can pediatricians give to families with young children?” he asks.

Oftentimes, these serious physical abuse cases in very young children result from a parent being frustrated with a crying baby and having no one to turn to. Leventhal says in such situations, a parent should just put the baby down and walk away for a bit.

“Crying for five minutes isn’t going to hurt the baby. But shaking can cause, in 10 seconds, serious damage that someone’s going to be sorry for for the rest of your life,” Leventhal said.

SOURCE: Leventhal et al. “Incidence of Serious Injuries Due to Physical Abuse in the United States: 1997 to 2009.” Pediatrics published online 1 October 2012.