Don’t get surgery on a Friday
If you have any say, you might want to avoid scheduling your next surgery on a Friday.
The most comprehensive analysis of what happens to patients who have surgery on Fridays versus Mondays, published in JAMA by more than a dozen US and Canadian researchers, is unequivocal: The people who underwent all kinds of procedures before the weekend suffered on average more short-term, medium-term, and long-term complications than people who went under the knife after the weekend was over.
The study was based in Ontario and included more than 450,000 patients who received one of the 25 most common surgeries between 2007 and 2019.
Previous studies have generally found the same effects across different types of health systems: One UK-based study had reported better outcomes for Monday surgeries after 30 days. A paper looking at Dutch patients detected higher mortality rates after one month for patients who had Friday surgeries compared to Monday. This appears to be a phenomenon no matter the country, as prior US-based research also attests.
People who received pre-weekend surgeries — defined as a Friday or a Thursday before a long weekend — were overall about 5% more likely to experience one of those complications within a year of their surgery than people who got post-weekend procedures (on Monday or the Tuesday after a long weekend). The effect was stronger for heart and vascular surgeries; it was negligible for obstetric and plastic surgeries.
Researchers found Friday surgeries were more likely to be performed by junior surgeons when compared to Monday surgeries. “This difference in expertise may play a role in the observed differences in outcomes,” they wrote, based on a statistical analysis that controlled for other factors.
There could also be fewer senior colleagues on the hospital campus for the junior physicians to consult with, the authors said. In addition, the weekend doctors and nurses may be less familiar with the patient’s case, raising the risk that complications will be caught later and therefore lead to worse outcomes.
Source: Vox, 21 March 2025