Many people expect to make up for skimpy nest eggs by working longer into their retirement years.

Unfortunately, a new survey found that those plans often don’t hatch.

Nearly 60 percent of recently retired Americans ended up leaving the work force sooner than planned, primarily because of poor health or because they were laid off or forced into early retirement by their employer, according to PNC Financial Services Group’s latest Perspectives on Retirement survey.

“The survey clearly shows that the age at which people expect to retire is not always in their control,” said Celandra Deane-Bess, senior wealth planner at PNC. “Economic uncertainty, employer actions and unexpected health issues often force individuals to retire earlier than they planned, which puts a premium on sound financial habits early.”

On average, workers who aren’t retired expect to stop working at age 67, according to the survey.

People who consider themselves to be on track with their retirement savings on average expect to retire earlier, at 65.7 years.

That compares with the expected retirement age of 68.2 years for people who acknowledge that they aren’t saving enough.

The survey, conducted by telephone in July, also found that women have more doubt than men about their ability to afford retirement.

Just over half of women polled, 51 percent, agreed with the statement, “I’m afraid I may not be able to retire.” That compares with 48 percent of men who responded that way.

Other key survey findings:

• Workers, who on average plan to retire at age 67, expect they’ll need enough savings to fund retirement for 21.5 years – or until they are 88.5 years old. Average life expectancy in the U.S. is about 10 years younger than that at 78.6 years, although some statistics show that among couples, there’s a 50 percent chance one of them will live to be 92.

• The most frequently named “burning question” about retirement savings was how much to set aside for health care expenses.

• Among retirees, 64 percent reported receiving a pension, while among those still working, only 43 percent said they were covered by a pension.