Peace of mind No, health checks-ups can do more harm than good
03:11 GMT, 24 July 2012
When Brian Mulroney, the former Canadian prime minister, went for a check-up in 2005 he was given a CT scan.
This discovered two small lumps in his lungs, and surgery was recommended.
The operation was complicated by inflammation of the pancreas — a serious condition which meant being in intensive care.
Part of the problem of looking for abnormalities in perfectly well people is that rather a lot of us have them
He spent six weeks in hospital but was readmitted a month later because a cyst, which had developed on his pancreas because of the inflammation, had to be removed as well.
This was clearly a horrible illness.
All those operations, scans, time off work, tests — but wasn’t it worth it if they caught the nodules early and saved Mulroney’s life Here’s the problem. The nodules weren’t cancer — they were benign.
Essentially, Mulroney had surgery and complications for a ‘problem’ that hadn’t actually been a problem.
‘Body MOT’ screening tests — like those the politician had — are done for people who are completely well and have no symptoms.
You might think, as a GP, I would highly recommend them for reassurance or early diagnosis of problems.
Indeed, there are hundreds of posh private clinics that offer ‘check-ups’ with all kinds of blood tests, ultrasound and even MRI and CT scans which are meant to give you ‘peace of mind’ — combinations of tests that cost from 100 up to several thousand pounds.
Some tests can be useful, but many are not. Some can end up doing us harm — as happened to Mulroney.
How could an innocent check-up be harmful
Former Canadian prime minister Brian Mulroney had surgery and complications for a 'problem' that hadn't actually been a problem
Part of the problem of looking for abnormalities in perfectly well people is that rather a lot of us have them.
The crux is that most of them won’t do us any harm.
So, for example, if you do MRI scans of the brain in people who are healthy, you will find that 1.8 per cent have a swelling in an artery, an aneurysm, and 1.6 per cent will have a meningioma — a type of brain tumour.
Yet these people have no symptoms and the vast majority will never develop any problems related to what the scan shows.
When pathologists examine prostate glands from men who have died from an unrelated cause, they find that between 45 and 80 per cent of the men — particularly if they’re older — have prostate cancer.
Yet this hadn’t caused them harm and wasn’t responsible for their deaths.
Or take heavy smokers, screened for lung cancer using CT scans. In at least 20 per cent of patients, cancer is picked up on the scan — but this is a ‘cancer’ that would grow slowly and would not affect the person’s life span.
You might think picking this up is good, safe medicine
Sadly, it’s not. These people are ‘overdiagnosed’ — they’re told they have cancer, when it won’t go on to cause symptoms or an earlier death.
But they are treated as though they have a life-threatening condition. This means they get the risks of treatment, without the benefits.
Medicine is getting better at picking up small, subtle or early things with highly sensitive scans or blood tests performed as screening check-ups.
This has created a massive dilemma because we’re not always good enough at working out which will cause illness or death.
So everything abnormal gets treated, whether with operations, radiotherapy or chemotherapy.
If you are overdiagnosed — given a label of a disease which was never going to harm you — there’s no chance you can benefit from the treatment. You can only get side-effects, like Brian Mulroney.
Overdiagnosis is one of the enormous issues in modern medicine, but most patients don’t know it. This is partly because of a strange paradox.
Whenever I try to ring alarm bells about the amount of screening tests we’re doing, there’s the ultimate reply: ‘Screening saved my life.’
Yet this isn’t the full story. The more unnecessary treatments that are given, the more people believe their lives have been saved by screening.
Giving lots of people a ‘false alarm’ from a disease they were never going to die of — and then pronouncing them ‘cured’ — makes it seem as though screening was successful.
In other words, the more popular a screening test is, the worse the test may be.
What if these people knew that the stress of the diagnosis and treatment was for a cancer that wasn’t going to harm them
In reality, overdiagnosis is a risk in most screening tests, such as the national screening programme for breast cancer.
As the Mail has previously reported, around a quarter of women diagnosed with breast cancer as a result of routine mammograms are overdiagnosed — they were treated with surgery, chemotherapy or radiotherapy for a cancer that wouldn’t have harmed them.
What patients need to remember is that the pros of screening should outweigh the cons.
So, for example, newborn babies have a heel prick test a few days after birth to check for several rare diseases.
These need early treatment — like thyroid abnormalities — which can make a huge difference to the well-being of the child.
So the UK National Screening Committee recommends that these tests are routinely provided and fully funded on the NHS.
And people with diabetes are recommended regular eye tests to avoid complications from the disease.
But what about people going for a private screening check-up
These can cost several thousand pounds. How sure can we be sure that the advantages win over the risks of unhelpful diagnosis
Well, I don’t think we can. So, for example, Preventicum in Harley Street, London, offers an ultrasound of the arteries in the neck.
A narrowing of these arteries can lead to a stroke. So wouldn’t it be a good idea to find out about them before they cause one
It sounds temptingly logical. In people who have had a stroke or a ministroke, having this scan to see if further treatment is needed is very useful.
But for people who are completely well and haven’t had a stroke or mini-stroke, the research is compelling — for not doing it.
The problem is that an operation to correct the narrowing of arteries is more dangerous — with complications including death and actually causing a stroke — than the risk of a stroke happening through not operating.
This balance of risks is the reason why the ultrasound is not offered on the NHS.
Another company offering carotid ultrasound is Life Line Screening.
Like many readers, I received a letter from them — to my home address — saying: ‘Why doesn’t your GP order these screenings
'The answer is that typically such preventative screenings are not available from the NHS without the presence of symptoms and family history.’
But this isn’t true — it’s because they aren’t useful, and come with risks.
Many of the adverts for private screening clinics make it seem as though you are taking a risk with your health if you don’t take up their tests.
The truth is it’s a gamble if you do.
I was recently involved with an investigation from the independent consumer organisation Which, who telephoned five such clinics that used CT and MRI scans to get further information about the tests they ran.
Three of them didn’t mention the risks of overdiagnosis, and one only partially covered the risks.
Surely if you are going to spend around 3,000, you would want to have the potential for harm spelled out at the first opportunity
Potential patients need to know what they’re getting into — well before they get into the costly screening scanner.
Margaret McCartney is a GP based in Scotland. Her book, The Patient Paradox, is published by Pinter and Martin (9.99).