As the concern over health care costs and the troubled US economy have risen in the recent months, the American workers’ confidence in a calm and comfortable retirement has decreased in the last year by a rate unmatched in 18 years, according to a survey released on Wednesday.

The Retirement Confidence Survey showed that only 18 percent workers believe that the will afford to have a comfortable retirement, down from 27 percent in 2007, the biggest one-year drop in the 18-year history of the survey.

Retiree confidence in having a financially secure retirement also went down to 29 percent, 12 percent lower than a year ago.

Even if the confidence faced a decrease among all groups of ages and income levels, the sharpest decline was seen at younger workers and those with low incomes.

The RCS results reflect the fact that most retirees’ concern particularly regards health care costs. While 54 percent of those that quit work earlier than planned did it due to health problems or disability, 44 percent of all retirees said that they spent more than expected on health issues. In addition, more than half of retirees, that is 54 percent, are less confident in their financial future than they were at the moment of their retirement, compared to 40 percent in 2007.

"In the nearly two decades we have been conducting the RCS, this year's results show a very dramatic reduction in the public's confidence about having a comfortable retirement. The economy and health costs are major concerns," said Dallas Salisbury, president of the nonpartisan Employee Benefit Research Institute (EBRI), which conducted the survey with Mathew Greenwald & Associates.

"If there is a silver lining, it's that Americans finally may be waking up to the realities of being able to afford retirement," Salisbury also added.

The survey also showed that almost half of workers have calculated the money they need for a comfortable retirement, showing growing concern over the matter, while in 1996, only 29 percent of American workers did that. However, the survey said that it found that making retirement savings calculation is a good step toward a nice retirement. Of those that did this, 44 percent changed their retirement planning and 59 percent started saving more or investing more.