Health screening needs independent regular re-evaluation

From tentative beginnings over 70 years ago,1 screening to detect disease or risk factors before symptoms appear has become a familiar feature of modern healthcare. Screening delivers a mix of health benefits, harms, and costs.23 Importantly, these outcomes are not constants: they change with new evidence, vary between contexts, and over time.

Screening practices (whether organised as programmes or not) tend to be slow to react to these changes; alterations are often resisted and controversial.45 The reasons include financial interests, attention to sunk costs, lack of high certainty evidence or proper evaluation of existing evidence, a problematic belief that earlier detection is always better, or simple inertia or preference for the status quo.67

Screening programmes are often financed within finite collective healthcare budgets. They target asymptomatic people, most of whom are not those who need healthcare most. Continuing screening in the face of changing circumstances therefore deserves careful consideration, as it potentially leads to harm to healthy citizens and waste of scarce resources.

While there are well established principles for starting screening,1 none exist for stopping it.8 As experts who have worked on screening over many years, we see an urgent need for clear, agreed methods for actively re-evaluating existing practices that address inherent biases towards maintaining the status quo.