• Clinical Decision-Making
• Early Diagnosis
• Evidence-Based Practice
• Health Care Quality, Access, and Evaluation
• Policy

All tests ‘(…) do harm; some do good as well, and, of these, some do more good than harm at reasonable cost.’ Muir Gray and Angela Raffle.1

Medical tests are widely and increasingly marketed directly to consumers via traditional and social media.2 Such tests may diagnose disease, detect biochemical or hormonal imbalances, or characterise physiological states. Tests come in different forms including self-diagnosis questionnaires, home testing kits, blood tests, as well as tests consumers can request in healthcare settings with or without a doctor’s involvement. Examples include tests for vitamin deficiency, thyroid function, cancer, mental health conditions, and sexually transmitted infections. The complexity of these tests varies substantially. Some direct-to-consumer testing may involve a degree of clinical input, for example, a computed tomography (CT) performed for lung cancer screening while other tests can be performed with minimal to no involvement of clinicians, for example, Human Papilloma Virus (HPV) self-testing. The premise of such tests marketed directly to the public or consumers, is that they enhance individual autonomy and help people make better personal health decisions to improve their health or well-being. Tests performed in healthcare settings may have undergone more stringent validation than home tests; however, all direct-to-consumer tests inevitably lead to harm, and their benefits are often not documented in many such settings.

To decide whether to use any tests directly marketed to them, …