NEW YORK (AP) - America uses flawed methods to tally and analyze the deaths of children who have been maltreated, and the latest annual estimate of 1,770 such fatalities is likely too low, the Government Accountability Office says in a new report to Congress.

Better data, says the GAO, would aid in developing strategies that could save many children's lives in the future.

The GAO report, the subject of a House Human Resources subcommittee hearing Tuesday, says state agencies and the Department of Health and Human Services should broaden the scope of data collection, improve coordination, and seek uniform definitions of abuse and maltreatment.

"We need to do a much better job working together at the local, state and national level," said Theresa Covington, director of the National Center for the Review and Prevention of Child Deaths, in testimony prepared for the hearing.

In his opening remarks, the chairman of the House subcommittee, Rep. Geoff Davis, R-Ky., evoked the death of 2-year-old Caylee Anthony, whose mother, Casey, was acquitted of murder last week in a trial that drew worldwide news coverage.

"Sometimes the death of a child from maltreatment does not make headlines at all, possibly because it is not recorded as a death from maltreatment," Davis said.

"It is hard to know which child deaths are more tragic - those we know about, or those we do not," he added. "Our role is to be the voice for the voiceless - especially those children whose deaths are missing from official data today."

The main source of nationwide data on child-maltreatment deaths is the National Child Abuse and Neglect Data System (NCANDS), which issues an annual report based on information submitted voluntarily by the states. NCANDS' latest report, for the 2009 fiscal year, estimated that 1,770 children had died from abuse or neglect, up from 1,450 in 2005.

The GAO notes that many state officials believe that increase stems at least in part from new procedures and better reporting, rather than a surge in abuse of children. But reporting standards differ widely from state to state.

Some of the problems highlighted by the GAO:

• Nearly half of states included data only from child welfare agencies in reporting maltreatment deaths to NCANDS. Yet not all children who die from maltreatment have had contact with these agencies, likely leading to incomplete counts due to lack of data from coroners' offices, law enforcement agencies and other sources. One study cited by the GAO found that maltreatment deaths in three states were undercounted by 55 to 75 percent.

• HHS collects some information about maltreatment deaths, such as perpetrators' previous abuse of children, yet does not report it. And the federally funded center for child death review does not synthesize or publish the detailed data that it collects from states about maltreatment deaths.

• At the local level, lack of medical evidence and inconsistent interpretations of maltreatment challenge investigators in determining whether a child's death is caused by maltreatment. At the state level, limited coordination among jurisdictions and state agencies, in part due to confidentiality or privacy constraints, poses challenges for reporting data.

According to the GAO, state officials said that better data on maltreatment deaths would enable them to craft more effective prevention strategies – comparable to already widespread efforts to curtail the problem known as shaken-baby syndrome.

"As a society, we should be doing everything in our collective power to end child deaths and near-deaths from maltreatment," the report concluded. "The collection and reporting of comprehensive data on these tragic situations is an important step toward that goal."

It recommended that HHS expand the range of data that it distributes, while also helping states gather more complete and reliable information.

HHS, in a formal response, said it agreed with the recommendations and was taking steps to implement them.

Witnesses at Tuesday's hearing, in their prepared remarks, acknowledged that state and federal budget difficulties complicated any push for more funding to curtail child abuse. However, Michael Petit of the advocacy group Every Child Matters nonetheless called for up to $5 billion in additional federal spending.

Jane Burstain of the Center for Public Policy Priorities, a think tank in Austin, Texas, asked politicians to at least maintain current levels of spending on programs aimed at preventing abuse.

"As families struggle and stress levels rise, child maltreatment becomes more of a risk," she said. "To cut programs that support struggling families in tough economic times is the very definition of penny wise and pound foolish and is a choice our children will pay for with their lives."

Dr. Carole Jenny, a pediatrician and child-abuse expert at Brown Medical School in Providence, R.I., urged federal support for training more doctors in child-abuse pediatrics.

"When a child does die from abuse or neglect, these pediatricians can help police, forensic, and social service agencies make the correct diagnosis, by doing the appropriate medical work up in the hospital and by ruling out conditions that mimic abuse or neglect," she said in her testimony.

Another expert on child welfare, Richard Wexler of the National Coalition for Child Protection Reform, said the GAO report - by detailing the inconsistency of child-fatality data - highlighted the potential flaws in trying to rank states in this area.

"Phony 'scorecards' claiming state X or Y is 'worst' when it comes to child abuse deaths penalize states that are rigorous in ferreting out such deaths and reward states that ignore them," Wexler said.