Insurance companies are expecting health care costs to increase by an average of 10.5% over the next year, slightly less than the prior year, according to Aon Consulting.

A survey of more than 60 leading health care insurers, representing more than 100 million insured individuals, found that health care costs are projected to increase by 10.4% for HMOs, 10.4% for POS plans, 10.7% for PPOs and 10.5% for consumer-directed health plans.

One year ago, HMO cost increases were 10.6% and POS plans were 10.5%, while PPOs and CDH plans saw the same increase as this year.

“Aon Consulting conducts a health care trend survey twice a year to forecast the expected future increase in employer-provided health plan claims cost, before any plan changes, based on input from leading health plan actuaries,” said John Zern, Aon Consulting’s U.S. Health & Benefits Practice director, in a statement. “This data helps employers evaluate the competitiveness of health insurance premium renewals. For employers with self-funded health plans, it helps in developing future claim estimates for budgeting purposes.”

Zern added, “While we’re seeing a slight decrease in the trend rates, it’s still at double digits, and this year, it’s compounded by a struggling economy, lower wage increases, and in some cases, salary freezes.”

Prescription drug costs are expected to increase 9.3%, which is slightly lower than the 9.4% rate of increase one year ago. The specialty pharmacy increase is forecast at 13.2%, an increase from the 12.4% in 2008.

Aon Consulting points to the sluggish rate of drug adoption across the board, compounded by the FDA’s reduced rate of drug approvals – especially for new molecular entities and biologic products – as the contributing factors leading to this decline.

In addition, health care rate increases for retirees over the age of 65 are projected to be 6.6% for Medicare Supplement plans and 7.3% for Medicare Advantage plans, down from 7.3 percent and 7.7%, respectively, in 2008.