The front page of today's Daily Mail made for grim reading: "Thousands dying of thirst on NHS". The article in question told of hospitals failing to recognise a common kidney problem and that - with better treatment - "up to 42,000 deaths a year could be avoided".
There are many reasons why someone's kidneys might stop functioning and they might develop what's known as acute kidney injury (or AKI). Dehydration is one possible cause.
However, the number of people dying from AKI is not an indication of the number of people dying of thirst, as the Daily Mail's headline implies.
Acute kidney injury - avoidable deaths
If your kidneys malfunction, there's no way for your body to clean your blood. AKI develops easily when people are already ill and their immune system is weakened.
The Daily Mail's statistic of "42,000 avoidable deaths" is one that the National Institute of Health and Care Excellence (NICE) has put its name to, as it informed us today. However, NICE's own press release actually mentions a more conservative figure: 12,000.
What's actually being claimed is that between 12,000 and 42,000 deaths are avoidable each year.
This calculation is based on a factsheet from the Kidney Alliance, which cites estimates that of 5.2 million emergency admissions in the UK (in 2011/12), between 5% and 20% are likely to be AKI (since it isn't always detected, we end up with a wide range). So that's between 262,000 and one million cases of AKI each year.
On top of that, it's estimated that 24% of patients with AKI will die from the condition. That results in between 62,000 and 210,000 deaths from AKI each year.
Finally, drawing on a 2009 study, about a fifth of all deaths from AKI were considered avoidable. This leaves us with between 12,000 and 42,000 avoidable deaths each year.
While the Daily Mail has featured the higher figure suggested by NICE, other sections of the media have preferred to quote the lower estimate.
Numbers dying of thirst in hundreds, not thousands
While NICE has calculated that up to 42,000 people might be dying of kidney-related illnesses, we can't say that all of these people have died of thirst.
The Office for National Statistics (ONS), which produces data on different causes of death, calculates the number of deaths from dehydration (where this is specifically mentioned on the death certificate).
What NICE (and the Daily Mail) suggest is that thousands of patients are dying from AKI without anyone realising. It's not that patients are necessarily developing the condition in hospital, but doctors and nurses are in many cases failing to detect it and treat it appropriately. A simple blood test will confirm whether or not someone is suffering from AKI.
The Daily Mail is not a lone voice when it suggests that - whatever angle you look at it from - there's a problem with how patients are being cared for. A 2009 study into deaths from AKI concluded that only a third of those who'd developed the condition in hospital received "good care". While a lack of water might contribute to a patient's deterioration, they will also need to be given medication and any potential infection will need to be treated.
No evidence of widespread neglect
While the Daily Mail has emphasised the risk of AKI patients dying from dehydration, there's no direct evidence to prove that thousands of deaths are due to this specific cause.
As the ONS has noted, even a death caused by dehydration doesn't necessarily mean a patient has been maltreated:
"It is possible that poor care may have been a factor in some of the deaths, but ONS data does not provide enough evidence to draw this conclusion."
The Daily Mail's front page implies there's a strong link between AKI deaths and poor care; it suggests that patients are being fundamentally neglected. While AKI is a widespread condition, and it is being midiagnosed and mistreated in places, saying someone has died from AKI is not the same thing as saying that someone has died of thirst.
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