Co-Founder, Niche Jobs
Many of us may find the current Government’s plans for the NHS worrisome. Whether you’re versed in the theories that underpin the direction they’re taking and are concerned by the philosophical implications therein or just don’t want a private and profit-driven company managing your health, the idea that the NHS will be improved by patient choice and the economic competition this involves just doesn't ring true.
Fortunately, we can now take gut feelings and back them up with academic research. On Monday the 10th June, the Lancet reported on a study carried out by London professors that highlight important flaws in the main study cited by David Cameron to support the idea of patient choice as "one way we can make things better for patients".
Troublingly, the most fundamental reason that the study by Zack Cooper and colleagues from LSE Health is flawed is because they fall foul of one of the simplest and most basic things that all scientists must be aware of: namely, that correlation does not imply causation.
Correlation does not imply causation
If you’re not familiar with this maxim, it’s really quite simple to understand. In context of this use, the word ‘correlation’ means that two things change at the same time. ‘Causation’ just means that something causes something else. When trying to work out why things happen, it’s important to remember that, just because something happened at the same time as another thing, it doesn't mean that one thing definitely caused the other.
A brilliant example often used to explain is that of pirates and global warming. Since 1820, the number of pirates has only risen. Since, global warming has risen too, does this mean that pirates cause global warming? Of course not.
At the beginning of the 20th century, it was noted that the number of people in mental health asylums was rising alongside the number of radios; surely, this made it clear that radios are bad for our mental health, perhaps because they cloud our judgement and distract us?
This is of course, total poppycock. Radios do not cause poor mental health – it just so happens that, at the beginning of the 20th century, radios were getting cheaper and mental health infrastructure and diagnoses were becoming more used too. The two circumstances have nothing to do with each other.
Cooper’s study, used by David Cameron to bolster the argument for the Health and Social Care Bill in 2011, makes the same basic and embarrassing assumption. Cooper and his colleagues looked at mortality rates for those suffering from heart attacks and measured this against the number of hospitals within travelling distance of the patients’ GP surgeries; they also considered data on various elective surgeries.
Following this study, Cooper’s team claimed to find that greater choice for elective surgeries led to less deaths from heart attacks.
So, hospital choice for elective surgeries prevents death from heart attacks?
Professor Alyson Pollock and her team from Queen Mary, University of London have pulled apart Cooper’s argument and find it deeply troubling.
The paper doesn’t actually look at how choice affects patient’s elective treatments or whether GP referrals change as choices change. They haven’t given any evidence that they noticed that patients generally choose their closest hospital when given choice, that heart attack sufferers do best when treated in specialist urban heart centres, that heart attacks aren't the kind of illness you book in for six weeks in advance and that changes in primary prevention and secondary intervention care may have had significant effects on how we deal with heart attacks. Finally, they make no argument at all to explain how data regarding elective operations has any relationship to what constitutes ‘a good choice’ or ‘good competition’.
Pollock did not mince her words when she described Cooper’s study:
“Our examination of this research reveals it to be fundamentally flawed, amounting to the conclusion that the paper simply doesn't prove either cause or effect between patient choice and death rates.
This work should not be quoted as scientific evidence to support choice, competition or the new Health and Social Care Bill.”
So, there we have it. For those of you who had a feeling the competition introduced by the 2011 Health and Social Care Bill was wrong, here’s your evidence. It’s based on a very poor study that doesn't give effective proof.