By Mark Daly
BBC Scotland investigations correspondent
Medics could be getting it wrong in as many as 15% of patient consultations
Hundreds of thousands of people could be misdiagnosed by doctors in Scotland every year, a BBC Scotland investigation has revealed.
Medics could be getting it wrong in as many as 15% of patient consultations in hospital and primary care.
But cases of misdiagnosis, which do not all result in harm to the patient, are not recorded anywhere in the NHS.
This has led to growing demands for better reporting systems to help doctors prevent it.
Diagnosis can often involve a lengthy process of elimination so not all cases of misdiagnosis damage the patient.
But many do, and there is currently no effective mechanism in place in the NHS to record these incidents, and there is no obligation on doctors to report them.
Patient charity Action Against Medical Accidents (AAMA) has called for a change in the law to make reporting of misdiagnoses a mandatory requirement of doctors.
AAMA chief executive Peter Walsh said: "We have 4,000 inquiries a year and of those in primary care a large proportion, perhaps about 50% of cases, involve misdiagnosis of some sort.
"We see no reason why it shouldn't be a legal requirement on healthcare organisations, including general practices, to report incidents that go wrong in healthcare, including incidents of misdiagnosis.
"It's ridiculous that we get so few reports when we know there are significant numbers of this going on already."
There is no obligation on doctors to report misdiagnoses
A review published recently in the American Journal of Medicine, about misdiagnosis in developed countries, suggested that up to 15% of all cases could be misdiagnosed.
Two of Britain's leading authorities on misdiagnosis told BBC Scotland they believed this figure of 15% applied to the NHS, and much more needed to be done to reduce it.
Professor Graham Neale, of the Centre for Patient Safety and Service Quality at Imperial College London, has been researching misdiagnosis for the past four years and wants to see improvements to medical training.
He said: "I think it's a very big problem, and a problem that we should address. But I think we're going to have to tackle it from both ends, try to get the colleges more involved in this and get senior staff to take this seriously, and then on the educational side bring it up from below."
The Scottish Patient Safety Programme was launched last year, but misdiagnosis is not listed as one of its key priorities.
However, earlier this year a Westminster parliament health committee report identified that: "Delayed or missed diagnosis in general practice is a significant problem, generating many complaints and claims."
Scotland's chief medical officer Dr Harry Burns said: "In Scotland there are something like 15 million contacts with GPs each year and the vast majority of them end up with the right treatment.
"I can't say it [misdiagnosis] is a major problem. It's a huge problem for the individuals affected by it and clearly that's unsatisfactory and clearly we have to do something about that - and that's about learning and making sure that diagnostic techniques improve."
The Investigation: Misdiagnosis was broadcast on BBC Radio Scotland on Monday 21 September, at 0900 BST.