Among the reasons for an older workforce, Mr. Shuford noted, was that many workers are impacted by changes in their retirement systems. The systems provide them with less money–even as amounts needed for retirement have increased because of gains in life expectancy.

Younger workers have been dropping out of the labor force, even as those in their fifties and sixties have continued to work.

While older workers are injured less frequently, when they do suffer an accident they have more severe claims with higher costs and longer recuperation times than younger workers, Mr. Shuford said.

Part of the higher claim costs, he noted, are replacement wages, with older workers paid more because their salaries are higher. But in the future, differences in average weekly wages may shrink, he said.

Differences in the types of injuries suffered by older and younger workers are also diminishing, Mr. Shuford said.

Workers in the 45-to-65 years of age category, however, generally require 40 percent more treatment for an injury than younger workers and the drugs they are prescribed are more expensive.

Mr. Wilson, in examining the numbers from his company's experience, found one figure he could not quite explain–the medical cost 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.

He advised that insurers should differentially reserve for older workers.

Mr. Shuford noted that even as older workers remain in the work force the percentage of those over 65 is still tiny. He said that over age 65, the average weekly wage drops. For workers over 55, some 17 percent of their injury loss time is a result of 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.