Some people who are admitted to hospital on the weekend for emergency or surgical care face a slightly higher risk of death than if they came to hospital during a weekday, but the effect is so small that it shouldn’t detract from seeking care, Canadian doctors say.

The "weekend effect" — slightly higher odds of dying for weekend hospital admissions — has been documented for some patients in hospitals in Canada, the U.S., U.K., Denmark, Australia and South Korea.

Vancouver Standoff 20121015

Patients coming to hospital on the weekend might be sicker compared with those arriving on weekdays, which could partly explain the 'weekend effect' on mortality. (Jonathan Hayward/Canadian Press)

In Thursday’s report from the Canadian Institute for Health Information, researchers looked at data on nearly four million urgent acute care admissions between 2010 and 2013 to try to understand the extent of the weekend effect.

"The first thing that I would advise against is delaying your care," said Dr. Chaim Bell, a staff physician in internal medicine at Mount Sinai Hospital in Toronto who reviewed the report for the institute.

"The second thing that you should recognize is any delays for patients in hospitalization are a higher risk than the actual weekend effect itself."

To illustrate how small the effect is, the findings mean that if patients admitted on weekends had the same mortality rate as those as weekdays, there would be about 400 fewer in-hospital deaths among urgent patients out of a total of 75,000 in hospital deaths a year. That’s about a 0.5 per cent drop in the number of in-hospital deaths each year.

No weekend effect was found for obstetric, mental health or pediatric patients.

Bell first looked at the weekend effect in 2001. He and the institute staff pointed to several potential explanations for the weekend effect:

  • There are probably sicker patients coming to hospital on the weekend compared with weekdays.
  • Patients with less severe conditions may delay getting treatment until weekdays.
  • Staffing levels may change. At Mount Sinai, the emergency department, intensive care unit and labour and delivery are staffed 24/7. In other areas and at other hospitals, staffing levels for physicians, therapists, pharmacists and technicians for specialized diagnostic services are reduced.

Staffing levels are reduced in both acute care and long-term care on weekends, said Janet Hazelton, president of the Nova Scotia Nurses Union in Halifax.

Diseases don't break for the weekend

"In some of our smaller facilities the nurses on the night shift will draw the blood. Not only do they draw the blood, which is normally something the lab technologists would do, but they actually put it in the machine and get the blood results and phone that to the physician, who oftentimes is not in the building," Hazleton said.

Dr. Chaim Bell

Dr. Chaim Bell says, 'Any delays for patients in hospitalization are a higher risk than the actual weekend effect itself.' (CBC)

In contrast, Toronto Western Hospital adopted seven-day-a-week stroke care in April 2013, including assessments and services such as speech language pathology, occupational therapy, physiotherapy and dietetics.

"Stroke is not a disease that looks at the calendar and decides to present just on weekdays," said Dr. Frank Silver, director of the stroke program at Toronto's University Health Network.

For other illnesses, delays in getting treatment could set patients back a couple of days in their recovery, Hazleton said.

"The delay in doing a hip, fixing a hip, a delay of two days could be very serious," she said. "That senior could develop pneumonia and they could ultimately die. We need to figure this out."

The study’s authors said Canada’s weekend effect was less significant than in other countries.

With files from CBC's Kas Roussy and Pauline Dakin