Weekend surgery? Higher risk of dying, says study

MANILA, Philippines – Should we schedule surgery earlier in the week?

Published Tuesday, May 28, in the British Medical Journal, a study by researchers at Imperial College London suggests that patients are at greater risk of death if they undergo planned surgery toward the weekend.

The study showed that mortality rates were lowest for patients who underwent surgery on a Monday. Toward the weekend, mortality rates increased. A patient was 44% more likely to die if his procedure was on a Friday than if it was on a Monday. The likelihood shot up to 82% on the weekend relative to a Monday.

The researchers came up with these findings after examining over 4 million surgical procedures done in English public hospitals between 2008 and 2011. Deaths that occurred within 30 days of surgery were used to calculate the mortality rates by day of the week on which the surgery was performed.

According to the researchers, the weekend’s higher mortality rate may indicate poorer quality of care.

“The first 48 hours after an operation are often the most critical period of care for surgery patients,” said Dr Paul Aylin, a clinical reader of epidemiology and public health at Imperial who led the study. “So if the quality of care is lower at the weekend as some previous studies have suggested, we would expect to see higher mortality rates not just for patients operated on at the weekend, but also those who have operations towards the end of the week, whose postoperative care overlaps with the weekend.”

A recent report from the UK’s National Clinical Enquiry into Peri-Operative Deaths lends credence to this conclusion. The report revealed that the majority of high-risk patients who died were not given acceptable surgical care.

Aylin hypothesizes that lower quality of care at the weekend may be owed to “less availability of staff, resources and diagnostic services.”

However, without more information on surgical care, the researchers cannot say for certain that the weekend’s increased mortality rate is a direct result of lower quality of care.

The study has broken ground in several ways.

“Unlike previous studies, we included both deaths in hospital and deaths after discharge,” said Aylin. Using deaths both in the hospital and after discharge removed potential bias against patients that die out of the hospital.

Prior to the study, the trend of greater risk of death at the weekend had already been researched in emergency procedures. The study suggests that this “weekend effect” is stronger in planned procedures.

In addition to the “weekend effect,” the study may also be the first to report a “weekday effect,” that is, a trend of greater risk of death in planned procedures toward the end of the week.

The BMJ, in an editorial accompanying the study, asks: “Should we re-think the scheduling of elective surgery at the weekend?”

“The scheduling of elective procedures, such as knee replacements, is wholly within our control,” wrote the editorial’s authors Janice Kwan and Chaim Bell from the Mount Sinai Hospital and University of Toronto.

“If weekend care proves to deliver poorer outcomes than its weekday counterpart, it might be argued that elective procedures should not be scheduled at weekends at all.”

Further research was needed, said the pair, into which types of procedures were affected by the so-called “weekend effect”, and which patients and surgeons were best suited for weekend elective surgery.

“Until then, we are left to think twice about the adage: ‘thank goodness it’s Friday’,” they wrote.

The study was conducted by the Dr Foster Unit of Imperial’s School of Public Health, which specializes in using and interpreting health data. The study was funded by Dr Foster Intelligence, a provider of healthcare information in the UK, and the UK’s National Institute for Health Research. – Cristina Acosta, with reports from the Agence France-Presse/Rappler.com

Hospital bed image from shutterstock