Weekend hospital admissions carry higher risk of death, study shows

Canadians who are admitted to hospital on the weekend for emergency medical or surgical care are slightly more likely to die than those who are admitted during the week, according to a new report from the Canadian Institute for Health Information (CIHI). The same study found no weekend effect for obstetric, mental health or pediatric patients.

Weekend Admissions and In-Hospital Mortality looked at 4 million urgent acute care admissions between 2010 and 2013 and found that those who underwent emergency surgery had 7% higher odds of dying if admitted on the weekend; emergency medical care patients had 3% higher odds. These numbers reflect the percentage difference between weekend and weekday mortality rates for each type of care. Studies conducted in the U.S., U.K., Denmark, Australia and South Korea have found a greater weekend effect. For example, a U.S. study published this year found 15% higher odds of dying for urgent care patients admitted on the weekend.

“There has been much discussion concerning a possible ‘weekend effect’ in acute care hospitals,” says Jeremy Veillard, Vice President, Research and Analysis for CIHI. “This study’s findings should increase public confidence that weekend admissions are safe.”

The study took a closer look at two conditions requiring immediate care: heart attacks and strokes.Timely access to diagnostic testing are often integral to successful outcomes for both conditions, yet the study found mixed results. Both heart attack and stroke patients waited longer for diagnostics on the weekend. Yet there was only a weekend effect for heart attack patients (8% higher odds of dying).

Another possible reason for the small but significant weekend effect: staffing levels. The study includes a case study of one hospital’s staffing level changes over the weekend. Frontline nursing staff numbers remain similar to weekdays, while physician and clinical staff coverage – which includes therapists, pharmacists and technicians for specialized diagnostic services – are reduced.

Finally, the study suggests that patients with less severe conditions may delay treatment until the weekdays. Daily admissions go down on average by 11% on the weekend.

“It is important to keep in mind that the study was only able to analyze the most serious outcome: death,” says Kathleen Morris, Director of 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 wait times.”

Information is based on data from all provinces and territories, but provincial comparisons are not available because of the small number of deaths related to Canada’s weekend effect. A summary of previously conducted Canadian and international studies is included.

Agencies/Canadajournal