Doctors issue warning over ad hoc screenings

Patients are being warned against using unregulated or ad hoc screening tests in a new report, published by the British Medical Association.

The report, from the BMA’s Board of Science, warns that unregulated tests may cause more harm than good and give inconsistent results.

The BMA said that the public should be “extremely wary” of unregulated screening, especially test kits than can be purchased via the internet or mail order.

The report warned that unregulated screening could put patients at risk, because the tests were unlikely to be based on sound evidence, have non-existent quality control and lack balanced information for patients. The report also warned that such tests were unlikely to include information and support for patients, in the event of a positive result.

Ad hoc screenings could result in false results, which could lead to potentially dangerous further investigations in ‘positive’ cases and possible delayed diagnosis in ‘negative’ cases, the BMA warned.

They could also lead to over-detection of latent disease, which could lead to treatment with possible side effects, for conditions that would not have caused a problem.

The BMA report highlighted a number of unregulated screening tests, which could pose problems.

Unregulated whole body CT scanning could lead many false alarms and also involved significant does of radiation. The BMA also warned that there was no evidence to suggest that CT screening is useful for people without symptoms, in spite of it being offered and promoted by some commercial companies.

Exercise electrocardiograms (ECG) were also criticised and the BMA warned that they were far more likely to give a false result if given to people without symptoms of heart disease.

Breast screening x-rays (mammograms), which are used to detect cancers in women over 50, were deemed unsuitable for detecting small cancers in women under 50. This could lead to further invasive tests and the possibility of surgery for women whose cancers may not have progressed during their lifetime.

This is why the NHS Breast Screening Programme offers screening for women aged between 50 and 70 only, the BMA said.

Prostate Specific Antigen (PSA) testing was also criticised. The BMA said that two thirds of men with high PSA did not have prostate cancer, while some men with prostate cancer did not have high PSA. The report said there was also no evidence to show whether treating localised prostate cancer did more harm than good.

The BMA report also criticised some aspects of private sector screening, saying there were “important concerns” about harms from inappropriate tests, lack of continuity of care, quality assurance and lack of support and advice, particularly in the area of genetic testing.

The BMA has called for the government to address the issues of ad hoc screening and improve the information available about formal screening programmes.

Commenting on the report, Dr Vivienne Nathanson, the BMA’s Head of Science and Ethics, said: “There is no doubt that some specific screening tests have the potential to save lives, but this does not mean that there are no associated risks. We must make sure that screening is of a high quality and that patients are given all the appropriate advice before they decide to participate.

(KMcA/SP)