Surgeries Scheduled on Mondays Yield Better Results Than Those Performed Fridays, Study Finds

Surgical instruments are used during an organ transplant surgery at a hospital in Washington on June 28, 2016. The Canadian Press/AP-Molly Riley

Individuals who can choose their surgery date might find that selecting a Monday is a safer bet than opting for a Friday, a new study suggests.

The risk of complications or death is five percent higher for patients who undergo surgery just before the weekend than for those who have their procedures earlier in the week, a team of researchers from Canada and the U.S. found.

The outcome discrepancy is known as “the weekend effect,” which refers to “the potential for worse patient outcomes during the weekends, compared with weekdays,” the authors wrote in their study, Postoperative Outcomes Following Preweekend Surgery. They say in surgery, this concept may also apply to those undergoing surgery immediately before the weekend, who receive postoperative care during the weekend.

The researchers noted that while the study focuses on Ontario, other studies have found similar outcomes across North America and Europe.

“Our study is consistent with the majority of published literature, indicating a greater risk of adverse postoperative outcomes among patients undergoing surgery before the weekend,” they said in the study published March 4 on the JAMA Network by the American Medical Association.

“Our findings underscore the need for a critical examination of current surgical scheduling practices and resource allocation.”

The Findings

The researchers analyzed data from more than 429,000 Ontario patients who underwent 25 frequently performed surgeries.

The surgeries analyzed ran the gamut from spinal surgery, coronary artery bypass grafting, and brain biopsies to knee and hip replacements, appendectomies, and breast reductions.

Researchers examined surgical procedures over a span of 12 years and evaluated patient outcomes at 30 days, 90 days, and one year after the procedure.

The researchers then compared the outcomes of patients who were treated right before the weekend with those who were treated immediately after the weekend. In every time frame analyzed, Friday surgeries were found to have a higher incidence of complications.

At the 30-day mark, patients in the pre-weekend cohort were more likely to face adverse outcomes, such as readmission, complications, and prolonged hospital stays in contrast to their counterparts in the post-weekend group. The odds of mortality were also increased in the pre-weekend group.

When the negative outcomes were aggregated, the likelihood of complications for patients treated on Friday was 8.49 percent, whereas for those treated on Monday, it was 8.13 percent, the researchers said.

At the 90-day evaluation, complication outcomes were recorded at 12.14 percent for Friday surgeries and 11.58 percent for Monday procedures. After a year had passed, the numbers were 22.64 percent for Fridays and 21.84 for Mondays.

The discrepancies may seem small, but in a sample of 1,000 patients, eight additional patients would experience complications if they received treatment on a Friday instead of a Monday, the authors said. That difference in outcome comes in at roughly 5 percent.

Reasons for Discrepancy

The weekend effect can be caused by a variety of factors, the researchers found.

Staffing disparities, availability of services, and challenges in care coordination, are likely to be contributing elements, the authors said, noting that hospital staffing numbers for doctors, nurses, and other clinical staff are “shown to sharply decline over the weekend.”

“A short-staffed weekend team may be less likely to detect and act on acute complications early in their evolution, leading to a higher complication rate for patients,” they wrote.

In conjunction with decreased staffing, there are also differences in the expertise of personnel during the weekend, they said.

“Our results demonstrate that more junior surgeons (those with fewer years of experience) are operating on Friday, compared with Monday; this difference in expertise may play a role in the observed differences in outcomes,” the authors said.

“These deficiencies are likely magnified by the reduced availability of resource-intensive tests, interventional procedures, and tools, which may be otherwise available on weekdays.”

The “small but significant” increase in surgery risk for pre-weekend patients deserves more attention from the health-care sector at large, the researchers added.

“The findings of this study may be used to guide health care decision-makers to address inefficiencies and better mitigate adverse outcomes brought on by the weekend effect,” the authors wrote. “It is important for health care systems to assess how this phenomenon may impact their practices to ensure that patients receive excellent care irrespective of the day.”