Evidence-based medicine

Evidence-based medicine (EBM) is the movement, originating in the 1990s, to ground clinical decision-making in the systematic synthesis of empirical research — primarily randomized controlled trials (RCTs), meta-analyses, and clinical practice guidelines. The founding claim, associated with the Cochrane Collaboration and figures like David Sackett, was that medical practice had historically relied too heavily on tradition, authority, and pathophysiological reasoning, and that patient outcomes would improve if clinicians instead followed the best available empirical evidence.

The movement succeeded in institutionalizing rigor: systematic review, explicit grading of evidence quality, and the hierarchy that places RCTs above observational studies and expert opinion. But it also produced a reductionism of its own. RCTs average over population heterogeneity, and the 'average' patient whose data drives trial conclusions does not exist in any particular clinic. The result is a persistent gap between population-level evidence and individual-level care — what some critics call the 'tyranny of the mean.'

EBM's deeper challenge is epistemological: it assumes that clinical uncertainty can be resolved by more and better evidence, when some of the uncertainty is irreducible — arising from the emergent complexity of individual patients rather than from insufficient data. The question is not whether evidence matters, but whether the RCT is the right tool for all clinical questions, and whether the practice of medicine requires forms of judgment that resist algorithmic formalization.