The percentage of U.S. adults who say they are not too confident, or not at all confident, about the affordability of health care has increased to 42% this year, from 36% in 2007.

Researchers at the Employee Benefit Research Institute, Washington, and Mathew Greenwald & Associates Inc., Washington, have published those figures in a summary of results from a survey of about 1,000 U.S. adults ages 21 and older that was conducted in the spring.

About 51% of the participants said they are extremely or very confident that they are able to get the treatments they need, but only 31% said they are confident that they can afford health care without financial hardship.

Only 55% said they had noticed an increase in health care costs in the past year, down from 63% in 2007.

Insured participants who said they have experienced an increase in health care costs in the past year are more likely than other participants to say they shop for health care more carefully.

About 74% of the participants who have noticed a cost increase said they use generics more often, compared with 60% of the other participants, and 62% said they go to the doctor only for more serious conditions or symptoms, compared with 48% of the other participants.