The Workers' Compensation Research Institute recently released a new study on workers' comp costs per claim and analyzed causes behind the increasing trends.

The study, CompScope Benchmarks for Maryland, compared workers' comp systems in 13 large states on performance measures — benefit payments and costs per claim, timeliness of payments, and defense attorney involvement — by analyzing similar groups of claims and adjusting for interstate differences in injury mix, wage levels, and injury types. The study states were Arkansas, California, Florida, Illinois, Indiana, Louisiana, Maryland, Massachusetts, North Carolina, Pennsylvania, Tennessee, Texas, and Wisconsin. These states represent more than 50 percent of the nation's workers' compensation benefit payments, according to WCRI.

Workers' comp costs per claim grew on average of 14 percent per year for claims evaluated in 2004, according to the report. The average growth rate for 2003 and 2002 was five to 11 percent per year. CompScope indicated that rising medical costs per claim was the major cause for this increase.