MONTREAL - Quebec hospitals have six months to change work schedules for medical residents after an arbitrator ruled that 24-hour shifts violate the Charter of Rights and Freedoms.

The decision comes after four years after a student filed a grievance against McGill University saying that working for 24 hours in a row put his health at risk, and threatened patient care.

Under the ruling doctors will only be allowed to work for 16 hours in a row, which many people say is still a very long time.

Dr. Alain Bestawros filed the complaint following several U.S. studies indicating that residents were more likely to make errors after being at work for 16 hours.

Patients' rights groups are happy with the ruling and say it will improve patient care .

Dr. Charles Dussault, president of the Quebec Medical Residents Federation, supported the grievance.

"We want to make sure that the care we offer to our patients is as safe as possible. Doing more mistakes within a 24-hour call makes no sense to us," Dussault said.

Long before this week's ruling three Montreal hospitals decided it was time to change their protocols.

Last year the Jewish General Hospital, the Royal Victoria Hospital and Montreal General Hospital decided residents studying internal medicine would work day shifts or overnight shifts, but not both.

Many medical professionals say doctors-in-training get the chance to learn and practice much more on the overnight shifts, and that will not be changed by the arbitrator's ruling.