Examining the “weekend effect” at Canadian hospitals

Patients admitted to acute care hospitals on the weekend have slightly higher odds of dying than those admitted on weekdays, according to a recent report by the ().

Weekend Admissions and In-Hospital Mortality takes an in-depth look at the so-called “,” examining four million urgent acute care admissions to Canadian hospitals, in all provinces and territories, between 2010 and 2013.

The report concludes that the odds of dying for Canadians admitted on the weekend for urgent medical or surgical care were four per cent higher than for patients admitted on weekdays.

CIHI’s report breaks down the numbers for patient groups.

  • Those who underwent urgent surgery had seven per cent higher odds of dying if admitted on the weekend.
  • Urgent medical care patients had three per cent higher odds.
  • There was no weekend effect for all other acute care patient groups—children and patients admitted for childbirth or mental health services.


Staffing, access potential factors

One possible reason for the weekend effect is staffing levels. CIHI’s report includes a case study of one hospital’s staffing level changes over the weekend. Front-line nursing staff numbers remained similar to those on weekdays, while physician and clinical staff coverage—which includes therapists, pharmacists and technicians for specialized diagnostic services—was reduced.

Delays in access to diagnostic testing may also be a factor. Heart attack and stroke patients waited longer for diagnostics on the weekend, yet there was a weekend effect for only heart attack patients (eight per cent higher odds of dying).

Another reason, the study suggests, is that patients with less severe conditions may delay getting treatment until weekdays. Daily admissions go down by 11 per cent on the weekend on average.

While the report provides much food for thought, experts stress the value of keeping the data in perspective.

“It is important to keep in mind that the study was able to analyze only the most serious outcome: death,” says Kathleen Morris, CIHI’s Director, Health System Analysis and Emerging Issues. “Individual hospitals are in the best position to monitor key contributors to successful patient outcomes: appropriate treatments, patient experience, and diagnostic and treatment wait times. Though Canada’s weekend effect is very small, hospitals could ensure that staffing on weekends is sufficient to meet best practice guidelines for the high-risk conditions seen in acute care.”


How Canada stacks up

Although small, the numbers related to Canada’s weekend effect are nevertheless significant. But how does Canada compare to other countries?

“There has been much discussion concerning a possible ‘weekend effect’ in Canadian acute care hospitals,” says Jeremy Veillard, Vice President, Research and Analysis at CIHI. He notes that the study’s findings—compared to all similar studies (national scope, looking into urgent cases across all diagnoses), including those conducted in the U.S., U.K.,  and Australia—reveal that Canada seems to have the lowest weekend effect in urgent care. “Our study’s findings are very reassuring to Canadians and should increase public confidence that weekend admissions are safe.”

The Canadian Institute for Health Information (CIHI) collects and analyzes information on health and health care in Canada and makes it publicly available. CIHI’s data and reports inform health policies, support the effective delivery of health services, and raise awareness among Canadians of the factors that contribute to good health.