Expensive “health MoT tests” aimed at the worried well are medically misleading and can even be dangerous, a report by senior doctors and scientists has found.

Healthy people have nothing to gain from spending hundreds of pounds on blood tests and scans that purport to give an early warning of medical problems such as heart disease or cancer, the experts said.

The report, from the Royal College of Pathologists and three other respected medical and scientific groups, said that while many tests included in commercial “well-man” and “well-woman” services have great diagnostic value for people with symptoms, they are clinically irrelevant for those who are well. The results often cause needless concern or false reassurance, and can lead to unnecessary procedures that can be invasive, painful and risky.

Some of the tests are also harmful in themselves. Computerised tomography (CT) scans involve exposure to radiation, and cause a fatal cancer in one in every 2,000 people. One in 1,000 colonoscopies leads to a perforated bowel.

Such risks are justified if there is good reason to suspect illness, but not for people who are apparently well, the expert panel said. It expressed particular concern about full-body magnetic resonance imaging (MRI) and CT scans, which often detect slight variations from the norm in healthy people. These would probably never have caused disease, but require investigations and raise anxiety.

Private medical screening is a multimillion-pound industry, with dozens of companies advertising scans and tests that they claim can detect diseases before too much damage is done.

The private health insurer BUPA performs 100,000 health assessments each year, offering a basic package that costs £430 for men and £460 for women, and which includes either 36 or 37 tests depending on age or sex.

Preventicum, a London clinic, offers an “ultimate check-up” for £2,950, which includes MRI and ultrasound scans as well as more than 40 blood and urine tests.

Home-testing kits are available for cholesterol, blood sugar, liver function and other biological markers of disease. The value of the market has been estimated at £99 million a year by the analyst Mintel.

The panel of GPs, medical scientists and patient representatives who compiled the report found little evidence that such services are of clinical value to healthy people. “For people without symptoms, there are only a small number of screening tests that are worthwhile,” it said. “Furthermore, testing the ‘worried well’ has definite potential for harm.”

The document, published today by the charity Sense About Science with the Royal College of Pathologists, the Association of Clinical Biochemistry, and the Population Health and Genomics Foundation (PHGF), also said the sector was inadequately regulated.

“With direct-to-consumer tests, anyone can set up a lab and sell testing. The test must measure what it says it will measure, but there’s absolutely no requirement for them to show the value of that test.”

Test providers said their services did not rely on single indicators and were interpreted by fully-qualified doctors. Garry Savin, medical director of Preventicum, said: “There is no doubt that over-the-counter DIY tests, which are unregulated, can often do more harm than good. However, there is no indication that undergoing health screening at a recognised clinic, overseen by an experienced healthcare professional who can accurately evaluate any results, poses any threat to the patient.”

Andrew Vallance, medical director of BUPA, said he shared the report’s concerns about home-testing kits and full-body scans, but said that there were great advantages to diagnosing diseases early.

“We insist that a doctor is part of the process, and because there is the issue with false positives and negatives we don’t do full-body scans or tests that have been poorly evaluated. By and large this is about motivating people to improve their lifestyle.”

Andrew Green, a GP on the Sense About Science panel, said: “Nobody should arrange their own medical tests. If you don’t have symptoms, then very few tests are worthwhile, and those that are can be had through your doctor.”

Checks and balances

Full-body CT scan

Pro can detect tumours or heart disease before symptoms become obvious

Con danger of false positives: often reveals slight abnormalities that would not have caused disease, but which require further investigation. Involves radiation exposure, with a 1-in-2,000 risk of causing cancer

MRI scan

Pro can detect tumours or heart disease before symptoms become obvious; no radiation exposure involved

Con danger of false positives: often reveals slight abnormalities that would not have caused disease, but which require further investigation; very expensive, at around £2,000

Prostate specific antigen test

Pro bio-marker that is sometimes raised among men with prostate cancer, and can give an early warning of the disease

Con very high false positive rate: many men with raised PSA levels do not have prostate cancer. Results must be confirmed by biopsy, which can cause infection, impotence and incontinence. Most men who have prostate cancer die with it, not of it

Liver function test

Pro finger-prick blood test, easily available via the internet for about £150

Con can be difficult to perform: squeezing out blood can dilute the sample, raising risk of false negative; NHS will perform it within 20 minutes to 24 hours if urgent; DIY tests take two to ten days. Some tests include just two bio-markers; NHS tests for five

Cholesterol test

Pro blood test that examines levels of LDL or “bad” cholesterol, linked to hypertension and heart disease. It can be clinically valuable to know cholesterol level is high if otherwise at risk of heart disease, as it can be lowered with drugs or lifestyle changes

Con tests are already routinely available through GPs for people at risk of heart disease

Source: Sense About Science, Times database

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