Patients having non-emergency operations on a Friday are 44% more likely to die than those having surgery on a Monday, researchers at Imperial College London have found in what they claim is the first study to show a "week-day effect" on hospital mortality.

While the overall risk of death is low, there is unacceptable variation in the risk of dying from surgery through the week, according to the report, which was published in the British Medical Journal.

Looking at data from more than four million elective procedures conducted in NHS hospitals in England between 2008 and 2011, the researchers calculated the crude 30-day mortality rate to be 6.7 per 1000 elective surgical admissions, or 0.67%.

However, the overall risk of death within 30 days for patients undergoing elective surgery increased with each day of the week on which the procedure was performed.

The death risk was found to rocket to 82% for surgery performed at the weekend, though it was noted that the number weekend operations was small and could also represent a different mix of patients.

Nevertheless, the findings could reflect significant differences in the quality of care experienced by patients over the weekend.

“The first 48 hours after an operation are often the most critical period of care for surgery patients," said lead researcher Paul Aylin, from the School of Public Health at Imperial.  "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. That is what we found."

"Not acceptable"

Antony Narula, Royal College of Surgeons council member and Consultant ENT surgeon, said "it is not acceptable that there should be such a wide variation in the mortality rates following elective surgery according to the day of the week the operation takes place," and he stressed "the importance of patients being seen on a daily basis by consultants, and also the need for full clinical support being available seven days a week in hospital to provide the best treatment".

Also commenting on the findings, Katherine Murphy, chief executive of the Patients Association, said while the research "once again highlights the NHS’s weekend malaise and makes for concerning reading, it unfortunately doesn’t identify a new problem, but rather a failure to address an issue that has repeatedly been highlighted in the past". 

"It is a shame that despite the publication of hundreds of pages worth of reports and recommendations that so little action has been taken to actually address the problems identified,” she said.