For Oregon, the 33 percent increase in the maximum weekly temporary total disability benefit resulted in a 17.5 percent impact on utilization.

NCCI said this implies a duration/benefit elasticity of 0.53 (17.5 percent/33 percent). The 7.6 percent increase in benefit duration in response to a 17.6 percent increase in the maximum weekly indemnity benefit in New Mexico translates into a duration/benefit elasticity of 0.43 (7.6 percent/17.6 percent).

In terms of temporary total disability indemnity costs to replace lost wages, both the Oregon (38 percent) and New Mexico (33 percent) studies show that approximately 35 percent of the total cost impact can be attributed to a duration utilization effect.

NCCI's report said its examination of Oregon data found that among TTD claims with long durations, the durations of female claimants exceed those of male claimants by about 20 percent.

Within the age bracket 20 through 60, on average, benefit duration increases for every year of age by 1 percent for Oregon and 0.72 percent for New Mexico, NCCI reported.

In Oregon, the maximum weekly benefit rose from 100 percent to 133 percent of the state average weekly wage effective Jan. 1, 2002. In New Mexico, effective Jan. 1, 2000, the weekly maximum benefit increased from 85 percent to 100 percent of the state average weekly wage.

"Some might interpret our findings to also conclude that a decrease in TTD indemnity benefits would result in a utilization impact. However, no such analysis was performed with which to reach such a conclusion," NCCI said in a statement with the report.

NCCI said its estimate of the utilization impact on claim durations from a change in statutory indemnity benefits reasonably agrees with estimates of prior studies, providing additional support for the inclusion of such utilization impacts in legislative cost analyses.

Producing more accurate and responsive cost impacts will enhance the legislative pricing and rate-making services offered by NCCI, and it will provide valuable information to aid public policy decision-making, the company said.