There is a growing market of new diagnostic tests being targeted directly to consumers, often before high-quality evidence about their effectiveness is available. This is causing issues in clinical practice as patients arrive at the NHS’s front door with results that have alarmed them.   The accuracy of these tests is unknown, developed in idealised populations then released to the general public, the positive predictive value of these tests plummet in the real world - but false positives require extensive further testing to rule out problems.   But advances in technology, with real potential, and commercial and societal incentives have aligned - these tests aren’t going to go away. So how do we start grappling with the power and pitfalls of early diagnosis - define exactly how we should be evaluating and regulating this growing industry, and what changes will we need to put in place in our healthcare systems to make sure an early diagnosis is good diagnosis?   In this podcast;   Peter Donnelly, professor of public health medicine at the University of St Andrews Bethany Jenkins, professor of health economics at the University of Leeds Stuart Hogarth, researcher at the University of Cambridge Andreas Halner, co-founder of Oxford Cancer Analytics Alex Richter, director of clinical immunology services at the University of Birmingham Carl Heneghan, director of the Centre for Evidence-Based Medicine at the University of Oxford. This podcast was recorded at the Evidence Based Early Diagnosis Conference