Self-Test Kits Could Do More Harm Than Good, UK Consumer Report

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Main Category: Medical Devices / Diagnostics
Also Included In: Prostate / Prostate Cancer;  Cancer / Oncology;  Diabetes
Article Date: 31 Mar 2011 - 11:00 PDT


Self-test kits could do more harm than good, said the independent UK consumer watchdog Which? today, after they recently reviewed six widely available home health kits and concluded they could be a waste of time, effort and money since they lacked important information and used misleading or baffling language.

Which? asked medical experts to review: a bowel home test kit and a blood glucose home test kit from Boots; a Self Check prostate health kit from ValiMedix; a cholesterol health care test from Care Diagnostica; a urinary tract test from Atlas, and a stomach ulcer screening test from Simplicity.

In addition to asking GP Dr Paul Singer and pathologist Dr Danielle Freedman from the Royal College of Pathologists to examine the six kits, Which? interviewed 64 members of the public about the home kits.

They concluded that the kits, which are available online or from chemists, could be useful, but they could also give false reassurance or cause unnecessary worry.

Based on their findings, Which? said there were 5 things consumers should be aware of about home test kits:

1. Are the kits easy to use?
   Although marketed as quick and easy to use, some of the kits Which? tested were not. For example, the bowel cancer test kit did not explain how to collect a stool sample, an important omission since the test requires non-contaminated samples. It also omitted advice on diet, for instance the importance of not eating red meat for three days before taking the stool sample.
   
   For two of the test kits, the experts had problems trying to draw the amount of blood required. In the stomach ulcer test, the expert only managed to draw three-quarters of the blood needed after pricking the finger twice in the place specified, and in the prostate test kit, the expert only managed to get half the amount required for the test. If you don't produce enough blood for the test, the results could be invalid.
   
2. Are there gaps in the information?
   Some tests fail to point out vital factors that could affect the results, for instance the blood glucose home kit that Boots advertises as helpful for early detection of diabetes doesn't tell you blood sugar is usually higher after a meal. Similarly, the prostate health kit doesn't point out that the isn't suitable after vigorous activity like cycling, or after sex, or if you have certain conditions, such as prostatitis.


3. Is the information clear about the test's limitations?
   As an example, Which? said their experts thought men might buy the Self Check prostate health test online without fully understanding its limitations with respect to false positive or false negative results. That type of test is known to have a high rate of false positive results, indicating presence of tumours that will never cause a problem. There is also a chance they will give false reassurance through false negatives.


4. Make sure you understand what they mean by "negative result".
   A negative result does not necessarily mean you don't have a condition. It is a bit like the old adage "absence of evidence does not equal evidence of absence". Thus, in the case of the prostate cancer kit, a negative result does not necessarily mean absence of prostate cancer, a condition for which an accurate diagnosis usually requires more than one type of test. This could be a worry if consumers use the tests as a way to avoid seeing their doctor. In their interviews with members of the public, Which? found that older men said they didn't like going to the GP, and even if they had symptoms, might rely on the negative result from the kit.


5. Look out for unclear, misleading or incomprehensible language.
   Which? experts thought the name Simplicity Stomach Ulcer Screening Test was misleading. The test looks for a particular bacteria which only leads to stomach ulcer in a minority of people. They also found the language on the website to be alarming and "unduly frightening" in that it says half the people in the world are infected with the bacteria and therefore at risk of stomach cancer.
   
   The consumers Which? interviewed were also baffled by some of the language in the test kits. For example, the instructions in the cholesterol health care test from Care Diagnostica tells the user to draw blood from the "hillside" of the finger, while the Boots blood glucose test kit uses terms like "dessicant", "in-vitro diagnostic device", and "separation membranes" to describe some of the components.

Which? chief executive Peter Vicary-Smith told the press that while the home kits could be useful, they lacked clear information on how to use them, and:

"As your GP may well have to carry out their own tests to confirm a positive diagnosis anyway, you may be better off saving your money and going straight to your GP."

The Department of Health urges people to be cautious about using home kits for health tests. They would prefer you to see your doctor, pharmacist or health professional if you think you have an infection or illness.

According to a BBC report, a Boots spokesperson said that their kits should always be used with advice from a pharmacist or a GP. But this is not strictly what the instructions say on the Boots website page for purchasing the cholesterol home test kit. They say you can use the kit to test your cholesterol for the first time, and then see your doctor if it the level is high enough; or if you are in any doubt about the instructions, then ask your your pharmacist or doctor for further advice.

A spokesperson for ValiMedix who sell the prostate test kit online told the BBC that their kit, which tests PSA levels was a "widely used" and "valuable tool" that can provide "an indication of the possible prostate abnormalities".

Phrases such as these should be enough to convince any sensible consumer using home kits to seek confirmation from a health professional before allowing themselves to feel reassured or concerned about a result.

Sources: Which?, BBC News (31 Mar 2011).

Written by: Catharine Paddock, PhD
Copyright: Medical News Today
Not to be reproduced without permission of Medical News Today

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