Older workers, while injured less frequently, when they do have an accident tend to file more severe claims with higher costs and with longer recuperation times than for younger workers, according to Mr. Shuford. Replacement wages also are higher for older workers, he noted.

As time goes on, however, the difference in average weekly wage is expected to shrink, he said, while the differences in the kinds of injuries older and younger workers suffer also diminish.

Aging does come into play with severity, as workers in the 45-to-65 category generally require 40 percent more treatment for an injury than younger workers, and the drugs they are prescribed are more expensive, he noted.

Ned Wilson, director of planning and treasury for FCCI Insurance Group, examining numbers from his company's experience, found one figure he could not quite explain--medical costs for the 25-and-under age bracket has risen 10 percent a year, compared with 7 percent in the 35-to- 54-year-old category.

Given broader severity trends, however, he advised that insurers should reserve differently for older workers.

Still, Mr. Shuford said that even as older workers remain in the work force, the percentage of those over 65 is relatively small.

In other trends, he noted that for workers over 65, the average weekly wage drops, while for workers over 55, some 17 percent of the lost time they have is caused by falls, which could be attributed to poorer eyesight and an inability to move as well.

To counteract these effects, he suggested company loss control activity might include better lighting, marking steps clearly and providing handrails. "There's a lot we can do to address these challenges," he said.