DURHAM, N.C. — Searching for a good nursing home for an elderly parent or relative can be difficult. Experts say one thing to look for is the turnover rate among the nursing staff.

Turnover rates can be extremely high and it can hurt patient care.

A new study sheds light on why so many nurses leave.

Nursing homes have a tough job keeping staff on board. National studies show registered nurses leave after only one year on the job, while nurse assistants stay only six months.

"You can imagine the nightmare that might create," Ruth Anderson of the Duke University School of Nursing.

Anderson says that high turnover rate can lead to substandard care. Anderson led a study of nursing homes showing a link between high nursing turnover and chronic under staffing.

"If they don't have time to spend that extra minute with the residents, that they feel they might be cheating the resident, they're always rushing in and out of the room -- that would contribute to turnover," she said.

The study also looked at the management style of nursing home directors. If the director leaves or is fired, other employees usually follow. When nursing director Diane Long arrived at the Forest at Duke nursing home, it took her 18 months to stabilize her staff.

Now, she enjoys a lower turnover rate than most facilities.

"You need to look after your employees so they can take care of the patients," Long said.

The study shows good communication is also important.

Long holds frequent meetings, sets clear expectations and rewards employees for good work.

When searching for a nursing home, Long recommends asking how long staff members have worked there -- especially the director of nursing. Ask about how much influence nurses have on day-to-day operations and how many beds are they responsible for.

"I might ask, 'Do you feel that you have what you need to give care?' because some places do not," Long said.

The study shows even facilities that cannot afford more help can do things to improve the working environment.

"Until we do that, we're going to continue to have this instability that is such a problem in the industry," Anderson said.

Experts say a stable nursing staff is especially important to seniors with mental impairments. They need familiar faces to be able to communicate their needs.