CHICAGO (CBS) –The University of Chicago will be paying replacement nurses $4,200 each to fill in for the nurses who went on strike Friday, according to a recruiting notice obtained by CBS 2.

The hospital administration is working with U.S. Nursing Corp, a Colorado-based company that specializes in providing medical staff to hospitals during labor disputes.

The nurses will be guaranteed 60 hours of work for at least five days at $70 an hour.

Including orientation done before the strike on Friday, the nurses were asked to be away from home for up to 10 days.

The nurses are required to be licensed in Illinois and have two years of acute nursing experience.

The U. of C. is also paying for travel and lodging, sources told CBS 2. The hospital would not provide a total cost to cover the hiring of the replacements. According to reports, a total of 2,200 nurses are on strike.

A study done in 2010 by the National Bureau of Economic Research found that in-hospital mortality increased by 19. 4 percent and hospital readmissions increased by 6.5 percent for patients admitted during a strike.

The study looked at 20 years of data in New York state.

“These poor health outcomes increased for both emergency and non-emergency hospital patients, even as admissions of both groups decreased by about 28 percent at hospitals with strikes,” the report found. “The poor health outcomes were not apparent either before or after the strike in the striking hospitals, suggesting that they are attributable to the strike itself.”

One of the sticking points in contract negotiations has been staffing. National Nurses United said the nurses have filed more than 1,700 complaints detailing staffing problems since January 2017.

The nurses said state law requires a one-to-four nurse to patient ratio, but they often have a one-to-six ratio in the emergency room.

The hospital accused the union of distorting the facts on staffing issues.

“Unfortunately, as we really made a generous proposal around that, recognized as a generous proposal by the union negotiator, she put additional things on the table as core issues, and it was clear that we’re so far apart on those that both sides determined there was no more productive conversation to be had,” University of Chicago Medicine senior vice president Debi Albert said.