Injury evaluation software, including CSC's Colossus package, allows insurance companies to "tune" payment perimeters and reclassify injuries as less serious than the diagnosis from a doctor, said the report, by Mark Romano, a former Colossus expert at Allstate Insurance, and Robert Hunter, a former insurance commissioner for Texas.

The claims software, adopted by many U.S. insurance companies in the past 15 years, "has enabled many insurers to increase profits by reducing the amount paid to consumers who filed bodily injury liability claims," .

Some insurance vendors have touted savings of about 20 percent after moving to claims software from using human adjusters, the report said.

The American Insurance Association, a trade group, questioned the results of the study, saying that most insurers use other methods, in addition to claims software, to determine payouts.

"While these useful tools help to apply fairness and consistency to the claims handling process, generally, trained claims adjusters are involved throughout the process," Willem Rijksen, vice president of public affairs at the trade group, said in an email. "Insurers are in the business of fairly and equitably paying claims as overseen by a well regulated insurance marketplace."