Interest in consumer-directed health plans continues to expand among employers and their workers. Why? They are both saving money.

According to the 15th Annual NBGH/Towers Watson Employer Survey on Purchasing Value in Health, just over half (54 percent) of companies now offer a CDHP, and that number is expected to grow to 61 percent in 2011. Nearly half (46 percent) of companies that offer a CDHP report that at least 20 percent of their workers enrolled, an increase of nearly 70 percent in five years.

Here is the good news when it comes to bending the health care trend: Companies with higher levels of CDHP enrollment also reported lower costs. The study found that those with at least 50 percent of their workers enrolled in a CDHP report average annual costs per employee of nearly $1,000 less than at non-CDHP companies. Similarly, nearly 60 percent of survey respondents indicate their workers pay premiums that are at least 30 percent less than those for traditional copay plans.