Last month we were confused by claims by the Health Secretary that "around 6,000 people lose their lives every year because we do not have a proper 7-day service in hospitals". The source for this was unpublished at the time, which meant its use by the government was inappropriate—members of the public should be able to interrogate the claims made by ministers.
On that basis we referred the case to the UK Statistics Authority (UKSA), which responded by inviting NHS England "to consider how best to supplement the information currently available so that users can understand the source of this estimate and how it differs from previous estimates."
The Department of Health has published more information on the figure. Research in 2012 calculated how much more likely someone was to die after being admitted to hospital at a weekend than after being admitted on a Wednesday. The Department of Health applied that ratio to actual numbers of deaths and concluded that if every day lived up to Wednesdays, there would have been 5,745 fewer deaths in hospital that year.
That's counting from the day a patient is admitted, and including all deaths within 30 days of that date, a common way of measuring mortality.
There's no way to know whether all of these deaths would have been prevented if care at the weekends were improved. Critics have argued that while the researchers have tried to account for differences in weekday and weekend patients, some of the increased risk could be down to the circumstances of individual patients rather than the way they're treated in hospital.
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 to 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 when they enter hospital, and it's not clear that expanding opening hours for NHS services would improve their chances.
For that reason it's fairer to say the evidence suggests that up to 6,000 extra deaths a year are associated with weekend admissions, and that some or all of this might be caused by poor care.
And it's an extra step to connect the figure to the number of lives that could be saved by the "7-day service" being suggested recently—one that isn't supported by this evidence.
An update to the research has now been published. This doesn't look specifically at excess weekend deaths, as it includes excess deaths associated with admission on Fridays and Mondays too.
Using data from 2013/14 it found 11,000 excess deaths associated with hospital admission on Friday, Saturday, Sunday or Monday, compared with the other three days of the week, saying:
"It is not possible to ascertain the extent to which these excess deaths may be preventable; to assume that they are avoidable would be rash and misleading."
Correction 11 September 2015
Following feedback we've corrected the paragraph beginning "For that reason it's fairer to say…" so it no longer implies the research covered here pertains to the "7-day service".
And we've updated with details of more recent research on 11,000 excess deaths.
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