Consumer-driven health plans linked to health savings accounts remain the CDHP of choice, according to a survey released Monday by Aon Consulting and the International Society of Certified Employee Benefit Specialists.

Of 370 respondents to the survey, the unit of Chicago-based Aon Corp. said 44% of employers now offer a CDHP to employees compared with just 28% in 2006. Of those offering CDHPs, 56% use the HSA model, 35% link CDHPs to health reimbursement arrangements and 9% use both.

According to the survey, the portion of employers offering HSA-linked CDHPs has risen from 48% in 2006 to 56% today, while the number offering HRAs has fallen from 43% in 2006 to 35% today.

“HSAs have grown in popularity relative to HRAs since HSAs are considered more advantageous to the employee than an HRA,” John Zern, director of Aon Consulting's health and benefits practice, said in a statement. “With an HSA, employees can contribute to their own money, the account is owned by the employee and is portable at termination of employment. HSAs also have great tax advantages.”

For CDHPs linked to HSAs, the survey found that 66% of employers contribute money, up from 60% last year. About 15% of employers contribute less than $500 per person, 45% contribute $500 or more and 6% match an employee's contribution.

Employers offering an HRA-linked plan make a variety of contributions, with 49% contributing between $500 and $799 to the account of a single employee and 34% providing more than $1,000 per year.

Today, 63% of employers responding have more than 10% of their workforce enrolled in a CDHP compared with 2006, when 53% had more than 10% participating in a CDHP.

“In our 2006 study, 66% of employers believed their employees did not enroll in the plan because they feared out-of-pocket expenses associated with high deductibles, and while this perception is lower this year, there is still room for improvement,” Bill Sharon, leader of Aon Consulting’s national consumer-driven health practice said in the statement. “Employers who have higher enrollment have designed their CDH plan to have similar out-of-pocket maximums and deductibles as traditional health plans such as HMO or PPO.”

While only 17% of employers in the survey have entirely replaced their health care plans with CDHPs, “we expect that number to increase next year,” Mr. Sharon said.