"It's a shocking fact, but mortality rates for patients admitted to hospital on a Sunday can be 16% higher than on a Wednesday..." - David Cameron, 18 May 2015
Shocking it may be, but it's also true. Patients had a 16% greater risk of death in the 30 days after being admitted to an NHS hospital in England if that admission happened on a Sunday than if it happened on a Wednesday, according to academic research published in 2012. That's after taking into account many (though not all) of the things that might have affected their chances, such as their age, diagnosis, and history of previous admissions to hospital.
This increase in risk is on top of a relatively small risk of about 1% for all admitted patients. So while it's still sobering news for anyone becoming seriously ill on a Sunday, they are on average still far more likely to be around 30 days later than not.
Use of the figure to argue for expanded opening hours—the "seven day NHS"—has been criticised. The research didn't look into whether the higher mortality risk was due to the way the NHS is run at weekends, meaning it can't tell us how much the policy would improve patients chances. It could be that people who go to hospital at the weekend are different in their underlying health than those who go on a weekday, in ways that the study couldn't control for.
An equally pertinent (and as-yet-impossible-to-answer) question is how much this, and parallel expansions to GP opening times, are going to cost. NHS leaders estimate the service in England will need a minimum of £8 billion more annual funding by 2020/21 in order to continue with current standards of care, never mind an expansion of what the service offers patients.
Increased mortality for admissions at the weekend
The study looked at 14 million admissions to NHS hospitals during the 2009/10 financial year. Of these, 300,000 patients died within 30 days of admission. These deaths occurred either in hospital or after the patient had been discharged.
Patients had a 16% greater risk of death within the 30 day period if they'd been admitted on a Sunday than if admitted on a Wednesday. That's adjusting for things like the age of patients or their social deprivation, which might otherwise have distorted the result. For patients admitted on Saturday the risk was was 11% higher than for Wednesday, and for Monday it was 2%. On other days of the week there was no statistically significant difference.
These higher risks applied only to those who were admitted at the weekend. Patients were more likely to die in hospital on a Wednesday than on a Sunday.
The research didn't aim to explain why it's riskier to be admitted at the weekend.
A number of potential causes have been put forward by NHS England, including that there are too few staff at weekends, too few senior staff, and restricted access to diagnostic services. These issues are what the government aims to address with its seven day working proposals.
But there may be other causes. For instance, patients who have less-concerning symptoms may decide to put off going to hospital until Monday, or those who are most gravely ill might find it easier be admitted to a hospice during the week than at the weekend. In both cases this would mean a bigger proportion of weekend patients are seriously ill, and it's not clear that expanding opening hours for NHS services would improve their chances.
This article was updated to take into account concerns over the figures raised by Dr Margaret McCartney in an article in the BMJ. We've also added in more detail of what the overall risk is for patients admitted at the weekend.
Isn't it nice to have the whole picture?
We rely on your donations to continue and grow our factchecking efforts - to help us maintain our independence we need 1000 donors to give £10 a month. We are currently at 502 - please help Full Fact grow.