The surge in the number of veterans suffering post-traumatic stress disorder requires development of better tests to evaluate affected personnel and determine how best to compensate them, a panel of medical experts said Tuesday.

"As the increasing number of claims to the VA shows, PTSD has become a very significant public health problem," said Nancy Andreasen, chair of the committee that prepared the report.

"Our review of the current methods for evaluating PTSD disability claims and determining compensation indicates that a comprehensive revision is needed," said Andreasen, head of the psychiatry department at Carver College of Medicine, University of Iowa.

Claims increased from 120,265 in 1999 to 215,871 in 2004 and payments jumped from $1.72 billion to $4.28 billion in the same period, a combined committee from the Institute of Medicine and National Research Council said.

While the largest share of claims is still coming from Vietnam War veterans, there are expected to be many more claims in future from personnel who served in the first Gulf War and in the current conflicts in Iraq and Afghanistan, the panel said.

But the Veterans Affairs Department uses only crude criteria for rating disabilities due to mental illness and is not consistent for relapsing conditions, according to the report, which had been requested by the VA.

The panel urged the VA to develop new criteria based on the diagnostic standards of the American Psychiatric Association and to establish certification programs for workers who deal with PTSD claims.

The panel said the VA should base compensation decisions on how greatly PTSD affects all aspects of a veteran's daily life, not just his or her ability to be gainfully employed.

The report also noted that PTSD can be triggered by trauma other than combat, such as sexual assault. Female veterans are less likely to receive compensation for PTSD, which may in part be due to the difficulty of substantiating exposure to traumatic events unrelated to combat, including sexual harassment or assaults that occurred during service, the report said.

It urged the VA to gather data and provide reference materials to help disability raters better address the management of PTSD claims related to sexual assault during military service.

The Institute of Medicine and National Research Council are branches of the National Academy of Sciences, an independent organization chartered by Congress to advise the government on scientific matters.