Injured workers sought out fewer prescription drugs in 2015, but workers compensation insurers spent 2.2 percent more on drugs as a result of higher prices.

A report by Express Scripts, a benefits manager, found that the average cost of prescription medication for workers comp beneficiaries rose 4.4 percent last year, which more than made up for the fact that workers were using prescription medications 2.6 percent less than the previous year.

There were particularly big increases in the cost of specialty medications, which account for less than 1 percent of the drugs prescribed to beneficiaries. Insurers spent nearly 50 percent more on such drugs in 2015 than in 2014, at an average per-prescription cost of roughly $1,800.