Commentary: trials versus models in appraising screening programmes

摘要

Sherlaw-Johnson and colleagues raise some important issues about methods for assessing screening programmes and, indeed, any healthcare intervention. Does the standard approach for assessment—the experimental trial—have a competitor in the mathematical model? Experimentation is an investigatory method whose strengths, especially in its gold standard, the randomised control trial, are well known. It frequently offers the most reliable route to establishing the impact of a healthcare intervention, particularly in areas without a strong theoretical underpinning, which are all too common in health care. Yet experiments have their weaknesses. Trials can be expensive, can present ethical difficulties, and can take a long time—even to the extent that the intervention under investigation has been superseded before the trial ends. It can be difficult to extrapolate from study findings about aggregated groups of people to subgroups, let alone to individual patients. Trials can generally test only a small number of intervention options.