A large-scale review of NHS data has uncovered further evidence that people are more likely to die if they are admitted to hospital at weekends.
Patients are 16% more likely to die if they are admitted on a Sunday than a Wednesday, and 11% more likely to die if they are admitted on a Saturday. For every 100 deaths following admissions on a Wednesday, 116 occur for admissions on a Sunday - a "significant increased risk", the researchers said.
It follows a report in November which found patients needing emergency care are almost 10% more likely to die if they are admitted on weekends and are less likely to receive prompt treatment.
The new analysis covered all admissions - more than 14.2 million - to NHS hospitals in England during 2009/10, including both emergency and planned admissions. It looked at more than 187,300 patient deaths within 30 days of being admitted to hospital. The researchers found higher death rates if patients went in on a weekend but a slightly lower death rate if people were already in hospital on a weekend.
Being already in hospital on a Sunday led to an 8% reduced risk of dying on that day compared to already being in hospital on a Wednesday. The medical conditions resulting in the biggest number of in-hospital deaths included pneumonia, congestive heart failure, heart attack, septicaemia, acute renal failure, urinary tract infections and neck or hip fracture.
The experts, including from University College London and the Universities of Birmingham and East Anglia, wrote in the Journal of the Royal Society of Medicine (JRSM): "We identified a significantly higher risk of subsequent in-hospital death during the 30-day follow-up period associated with admission during the weekend (Saturday or Sunday), compared to mid-week days.
"Admission on Tuesday through Friday was associated with the lowest risk of in-hospital death, while admission on Sunday was associated with the highest risk. Admission on Saturday was associated with a marked increased mortality (death) risk and admission on Monday was associated with a less, but statistically significant, increased risk."
Lead researcher Professor Domenico Pagano, from the University Hospital Birmingham Foundation Trust, said several reasons may be behind the findings, including that patients who are seriously ill can find themselves admitted on weekends. If they were less ill, they would have had their admissions postponed until a week day.
On Sunday, Health Secretary Andrew Lansley suggested more could be done to boost the number of senior doctors working weekends. Mr Lansley told the Sunday Telegraph: "By opening some services seven days a week, more patients will get the care and treatment that they need when they need it."
Mr Lansley added: "It is unacceptable that patients admitted to hospital on a Saturday or Sunday stay longer and have worse results. Much of the rest of the country continues to be open for the public's needs at weekends - an NHS that revolves around patients should be the same."