Underlying U.S. health care cost trends for commercial health plans are continuing to rise more than 10% per year.

Researchers at Buck Consultants, New York, have published that conclusion in a summary of results of an informal survey of 70 health insurers, health maintenance organizations and benefit plan administrators.

The participating organizations provide health coverage for 58 million members of employer-sponsored health plans.

Preferred provider organization plans dominate the employer health plan market.

Costs now are going up an average of about 10.9% at the participating PPOs, down from an average increase of 12.7% a year ago, Buck researchers report.

The average reported increase for the current year was about the same for point-of-service plans and HMOs.

Although advocates of high-deductible health plans say combinations of HDHPs and health savings accounts or health reimbursement arrangements can rein in increases, the average increase at the participating HDHPs was 11%, or about the same as the increase for conventional PPO plans.

The prescription drug cost trend increase has fallen to 8.2%, from 11.1% a year ago, Buck researchers report.