DIY disease testing kits criticised

The tests, which claim to help you check your cholesterol levels, and look out for early warning signs of osteoporosis and even Alzheimer's disease, are growing in popularity.

However, specialists employed by Health Which? magazine say that many of them should be withdrawn from sale as they are not reliable and may even be misleading.

The tests are designed to be used in conjunction with GP visits.

But Health Which says their ability to deliver very bad news without the support and extra information offered by a doctor is not a good idea.

Tests for bowel problems, for example, looked for the presence of blood in the stools - which can be an early sign of bowel cancer.

However, it can also be a symptom of piles, ulcers and a side-effect of taking various medications - and experts were worried that people using the test and getting a positive result would automatically think the worst.

Coming in for the most criticism were tests for Alzheimer's, high cholesterol levels and osteoporosis.

Smells rotten

One Alzheimer's test, for example, is simply a selection of "scratch and sniff" cards, in which various scents have to be identified.

A consultant psychiatrist asked by Health Which? said that while losing sense of smell was a symptom of Alzheimer's, smell testing did not figure in scientific evaluation of possible cases of dementia.

The "osteoporosis risk indicator" looked for the presence of high levels of a particular protein in the urine.

However, experts confirmed that levels of this protein fluctuated naturally.

Health Which? editor Kaye McIntosh said: "Companies manufacturing and selling these home testing kits are playing a dangerous game.

"Every kit examined had the potential to provide false reassurance to some and unnecessary concern to others, even though the manufacturers don't claim to be diagnosing specific diseases.

"No-one should use these tests instead of visiting their GP."

A spokesman for Boots - which markets many of the tests involved in the survey - said screening kits had "limitations" but nonetheless served a purpose.

"They can be useful if there is a history of certain conditions such as cholesterol, and they can be used to help people who wish to closely monitor their own health.

"These tests are not about providing a diagnosis, but that they can be the first trigger to take action and visit your GP."

The manufacturers also insisted the tests were never meant to be used for diagnosis.

Patrick Kirby, managing director of Wellbeing Screening Ltd, which makes the BodyWatch test kit for osteoporosis, said they were "screening" tools only.

"They are accompanied by information to make that clear and they advise that you should go to a doctor if you are in any doubt about the outcome of the test or if you have any symptoms."

Liberal Democrat health spokesman Dr Evan Harris said: "There may be a role for some of these tests, such as cholesterol and urinary glucose screening.

"But this must only be in a context where they can be interpreted by GPs, to avoid a false sense of security or unnecessary concern."