TORONTO -- Patients whose emergency surgeries are delayed due to a lack of operating room resources have an increased risk of death or a need for extra recovery time in hospital, a Canadian study suggests.

Researchers at the Ottawa Hospital found surgical delays for patients with serious injuries or life-threatening conditions such as a hip fracture, appendicitis or an aneurysm had almost a 60 per cent higher risk of dying compared to those who received more timely treatment.

The study, published Monday in the Canadian Medical Association Journal, showed that patients who didn't get into the OR within a standard time frame for their condition had an almost five per cent risk of dying, compared to a 3.2 per cent risk for those whose surgeries weren't delayed.

On average, delayed-surgery patients also stayed in hospital after their operation 1.1 days longer and cost the hospital $1,409 more than patients who did not have to wait.

"For the first time, we have strong evidence that the sooner you get to the operating room for an emergency surgery, the better off you are, regardless of your condition before surgery," said senior author Dr. Alan Forster, vice-president of quality, performance and population health at the Ottawa Hospital.

Urgent surgeries are those considered necessary within 24 hours of a patient being diagnosed, in most cases at a hospital emergency department. Such surgeries represent 13 per cent of all operations performed in Ontario, according to the Ontario Ministry of Health and Long-Term Care.

"Some surgeries need to be done very promptly," said Forster, an internist and researcher. "The hip fracture is a really good example because that's one that really should be done within that 24-hour time frame."

The reasons for delays were known in 39 per cent of cases. The most common causes for delay were that operating rooms were already in use or surgeons, anesthetists or surgical nursing staff were not available, he said.

"If you only have minutes or hours to plan, then you really have to have those resources available," said Forster, adding that it's difficult for patients and their families when an urgent surgery has to be put off.

"People are obviously very worried about their loved ones, they're obviously worried about themselves, they're often in discomfort as a result ... The best thing is to get folks into the OR immediately when they're supposed to be and minimize those anxieties, minimize their pain."

To conduct the study, the researchers examined data from 15,160 adults who had emergency surgery at the Ottawa Hospital between January 2012 and October 2014. They found that 2,820 of these patients, or almost 20 per cent, experienced a delay.

Researchers spent the first three months of the study collecting data on the demand for emergency surgeries. In January 2013, the hospital began using a new method for scheduling such operations, including dedicating OR time specifically for emergency procedures and spreading elective surgeries more evenly throughout the week.

After the hospital implemented this new model, there was a significant decrease in the number of urgent surgeries that had to be delayed.

"There was a massive improvement in patients getting to emergency surgeries on time with this new model," said Forster. "It might seem counterintuitive, but having unused time in expensive operating rooms could save both money and lives."

Still, he said there are certain barriers to implementing a system with operating suites designated for emergency surgeries -- which may at times sit unused.

"People running operations are always looking to make sure their budgets are maintained. It's difficult to create capacity and then plan not to use it."

In a related CMAJ commentary, Dr. David Urbach of Women's College Hospital, says the study findings provide the most credible evidence to date that long delays to emergency surgery are harmful.

"These findings will ring true for many of us who have worked in an operating room in a Canadian hospital," writes Urbach, surgeon-in-chief at the Toronto hospital.

"Global hospital budgets in an era of constrained public financing force surgical departments to strive for maximum efficiency; most optimize utilization of operating rooms and staff at maximum capacity for elective surgery, while assiduously avoiding any unbudgeted activity."

The authors note that even though the study was conducted at one centre, the findings are likely generalizable to other hospitals across the country.

"We need to think about how we make OR resources available for urgent surgery differently," said Forster.