Meta-analysis backs claims of dangerous 'weekend effect' after surgery

A meta-analysis of 29 studies and more than 6 million patients has added to a pile of evidence supporting medicine’s “weekend effect,” according to a study published in Medical Care’s February issue.

“Almost nothing is clear in this tangled tale,” professor Martin McKee wrote in a 2016 BMJ editorial, referencing the ongoing debate of hospital safety during weekends. The idea made its public debut two years ago, when British health secretary Jeremy Hunt took to BBC Today and claimed that 6,000 deaths could be avoided annually if hospitals were more readily staffed on Saturdays and Sundays.

Hunt’s claims may have been based on shaky evidence, but research conducted in the years since has backed the idea that surgeries scheduled for weekends have poorer outcomes than those that take place on Mondays, Tuesdays and Wednesdays. Even patients that schedule elective operations for Thursdays or Fridays, first author Stephen A. Smith, MD, and colleagues wrote in Medical Care, are still prone to the vulnerable weekend period since their early post-op recovery will take place during those days.

“Postoperative mortality rises as the day of the week of elective surgery approaches the weekend, and is higher after admission for urgent or emergent surgery on the weekend compared with weekdays,” Smith et al. wrote.

Smith and his team conducted an exhaustive review of PubMed and EMBASE literature, finding 10 elective surgery trials that met their criteria alongside 19 urgent/emergent studies. Operations included general surgery, cardiac surgery, orthopedic surgery, vascular surgery and neurosurgery, according to the study.

The researchers found that odds of death were hiked by 12 percent for patients scheduled for Thursday operations and 24 percent for Friday surgeries when compared with procedures that took place on Mondays. For patients admitted to hospitals on either Saturday or Sunday, odds of postoperative mortality were 27 percent higher than during the workweek.

“This phenomenon has become known as the ‘weekend effect’ and has been speculated to result from decreased staffing and resource availability, leading to shortfalls in care and poor outcomes,” the authors wrote.

These speculations have resulted in several research projects, but none as large as Smith and colleagues’. Though their findings do add fuel to allegations of a “weekend effect,” the authors were careful to discuss the limitations of their study, including the fact that they can’t identify the reasons behind the effect. In McKee’s editorial, he discounted hospital staffing as a possible answer, citing several studies.

Still, Smith et al. said, something is at play.

“These results are consistent with the presence of a ‘weekend effect’ in surgical care,” they wrote. “Future research should focus on clarifying underlying causes of this association and potentially mitigating its impact.”