Intended for healthcare professionals


Why blood testing companies need effective regulation

BMJ 2022; 379 doi: (Published 26 October 2022) Cite this as: BMJ 2022;379:o2517

Linked Feature

The rise of direct-to-consumer testing: is the NHS paying the price?

  1. Margaret McCartney, honorary senior lecturer1,
  2. Jessica Watson, GP, academic clinical lecturer2,
  3. Brian Finney, layperson,
  4. Chris Salisbury, professor of primary healthcare2
  1. 1University of St Andrews
  2. 2Centre for Academic Primary Care, University of Bristol
  1. margaret{at}
    Follow Margaret on Twitter at @mgtmccartney

Dozens of private sector companies are competing to offer blood tests to patients for a variety of purposes—particularly screening. As the cost of consumer testing falls, we highlight several areas of concern.

In the UK, regulation prevents prescription only medications being advertised directly to consumers, but not medical tests. The BMJ’s investigation has found dozens of companies offering health screening for a range of conditions and deficiencies through blood testing kits for use at home, often advertised to people with symptoms such as tiredness, low energy, irritability, sleep problems, and problems with weight.1

Symptomatic testing should not begin with pick and mix blood testing but with history taking, possible examination, and decisions on whether any test is necessary and beneficial. Pre-test probabilities are required to interpret and plan action on the basis of the test results. Patients should be informed that “normal” results may not provide complete reassurance or predict an outcome and that if they are experiencing ongoing symptoms they should seek appropriate healthcare. Conversely, apparently “abnormal” blood test results can cause patients undue stress and result in them seeking unnecessary healthcare.

Claims made by companies for screening often exceed the evidence base. One company offered a refund if none of the screening tests fell outside “normal” ranges.1 Given that reference ranges are conventionally defined as the range that encompasses 95% of the “normal” population, few people will have no “abnormal” results when multiple biomarkers are tested. In asymptomatic patients with low pre-test probability of disease the risk of false positives will therefore be high, whereas risk of disease will be low, leading to low positive predictive values.

Fully informed consent requires patients to receive a full explanation of the risk of false positives, retesting and associated anxiety, and the cost and time required to take the tests. In the UK the National Screening Committee and the National Institute for Health and Care Excellence use rigorous criteria to appraise screening tests. Few tests are recommended for screening. However, there are no regulations to prevent private companies from undertaking screening that is not evidence based. The Care Quality Commission for England does not regulate their advertisements, and although the Advertising Standards Authority can make judgments action may take months.

Private blood testing companies may also have negative effects on the resources of publicly funded health services like the NHS. While some companies offer a review of results by a medical practitioner (which may be charged separately), others do not. Patients often ask NHS GPs to review the results of blood tests that they have purchased privately, even tests not recommended by the NHS.2 These may be of uncertain quality, and liable to give false positive results, with follow-up consuming GPs’ and NHS laboratory time. The testing companies, meantime, may take no responsibility for management of results or the costs of subsequent investigations.

What should, and could, be done? People have a right to spend their money how they wish, but regulators should protect the public from unfair practices. The NHS needs to explain robustly the criteria for high quality screening and testing and to explain to consumers when they should be sceptical and what they should question. The NHS is a valuable and trusted brand: the NHS logo should be allowed only on apps that meet quality criteria, including not promoting screening or other activities that the NHS itself advises against. The NHS Choices website should provide advice from the UK National Screening Committee advice on private blood testing.3 This could be strengthened by citing cases where the Advertising Standards Authority has upheld complaints. The Care Quality Commission should be empowered to appraise apps that promote private screening, as well as the screening companies themselves, and the existing CQC mandate to assess the effectiveness of services should include the evidence base for screening tests. It is ironic that companies can be highly rated by the CQC if they have corporate policies in place, such as fire safety procedures, but can still be selling products that are not evidence based.

Guidance on mixing NHS and private care is now more than a decade old and does not reflect the new reality of patients who may dip in and out of private healthcare use. This guidance needs updating to draw clear lines as to where NHS care should start and end. Placing a responsibility on companies to undertake the further investigation of abnormal test results could help reduce the burden on the NHS. Unless clear regulation is undertaken, we predict more poor quality, overhyped testing with harms to individuals and unnecessary costs for the NHS.


  • Competing interests: MM has written and campaigned on issues connected with overdiagnosis and screening, some of which has been paid journalism.

  • Provenance and peer review: Not commissioned; not peer reviewed.