Is Evidence-Based Medicine Broken?
Last month, when the British Medical Journal asked its readers whether evidence-based medicine – defined by David Sackett as “the conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients” – is broken, the responses were almost evenly split. What is the problem?
LONDON – Evidence-based medicine, as David Sackett and his colleagues wrote in 1996, is “the conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients.” At first glance, this seems entirely logical; indeed, many would say that this simply could be called “medicine.” But the approach is generating considerable controversy, with many asserting that it is “broken.” Last month, when the British Medical Journal asked its readers whether evidence-based medicine is malfunctioning, the responses were almost evenly split: 51% answered positively, and 49% negatively.
The controversy stems from the kind of evidence that is used. Sackett implies, but does not stipulate, that epidemiological evidence (findings from randomized controlled trials and large-cohort studies carried out over many years) should underpin doctors’ decisions about patients – and, one hopes, in consultation with them.
Epidemiological research studies address questions like, “If 1,000 people with type 2 diabetes were randomly allocated to four groups of 250 people that each received either no treatment (or a placebo), drug A, drug B, or drug C for ten years, how would it impact survival rates, and what, if any, complications and side effects would there be?” If the trial is conducted properly – it is large enough; people are allocated in a truly random way; and “blind” assessments of the outcomes are conducted – the results should be reliable.