While employers remain committed to offering health and productivity programs, they are frustrated by the inability of many workers to change their health habits, according to a survey conducted by Towers Watson (NYSE, NASDAQ: TW), a global professional services company, and the National Business Group on Health (NBGH), a nonprofit association of large U.S. employers.

In an effort to encourage healthy behaviors, a growing number of employers are tightening their requirements for workers to receive financial incentives, according to the survey. Currently, more than half (53%) of large employers offer financial incentives to workers who enroll in health engagement activities, such as weight management or smoking cessation programs. But, for many employers, participation alone is no longer enough to earn an incentive.

Now, more than one-third of employers (37%) reward only those workers who meet the company's requirements for completion of a health engagement activity, and almost one-third (29%) only reward members who participate in multiple activities, according to the 15th Annual NBGH/Towers Watson Employer Survey on Purchasing Value in Health Care.

Still, most employers (93%) have no plans to eliminate their health promotion programs, and 83% have no plans to cancel or delay adding new ones.

The survey identified a group of "consistent performing" companies that have successfully held cost increases below the median trend for the last four years. In fact, these consistent performers experienced a median cost increase of just 2.1% over the last four years compared with 6.8% for all companies. These companies separate themselves from poorer performing companies in five areas: appropriate financial incentives, effective information delivery, metrics and evidence, quality care, and health and productivity. Consistent performers spent $6,536 per employee on health care benefits in 2009 -- nearly $1,200 less per employee than for all survey respondents.

Interest in consumer-directed health plans (CDHPs) continues to expand among employers and their workers.

Just over half (54%) of companies now offer a CDHP, and that number is expected to grow to 61% in 2011.

Nearly half (46%) of companies that offer a CDHP report at least 20% of their workers enrolled, an increase of nearly 70% in five years. Companies with higher levels of CDHP enrollment also report lower costs. Those with at least 50% 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% of survey respondents indicate their workers pay premiums that are at least 30% less than those for traditional copay plans.

"Employers and their workers face a challenging road ahead together," said Helen Darling, president of the National Business Group on Health. "Those companies most effective at empowering their workers to be engaged consumers of care will find greater success at keeping costs low and likely be rewarded with a healthier, more productive workforce -- an effort that has never been more important than it is right now."