Only about 24% of U.S. workers say they would be comfortable defining the term “health savings account” for someone else, and only 16% say they would be comfortable defining the term “formulary.”

Researchers at Watson Wyatt, Washington, have published those statistics in a summary of results from a recent survey of about 2,100 U.S. employees with health coverage.

Only 3% of the participants said they read no materials about their health coverage, and 52% said they read all of the materials.

But only about half of the participants said they could define two most widely understood terms, “co-pay” and “deductible,” and only about a third understood the terms “flexible spending account, out-of-pocket maximum” and “lifetime maximum,” the Watson Wyatt researchers report.