The age of exclusive professional knowledge, passed down through professional apprenticeships, was challenged throughout the 20th century by the rise of empirical research. In particular, the advent of the randomised controlled trial (RCT) in the 1950s led David Sackett and other epidemiologists to urge all clinical professionals to continuously appraise research evidence when making decisions in practice.1 The term ‘evidence-based medicine’ was coined2 and rapidly became the benchmark of good clinical practice. From the 1990s onward, research evidence took primacy over professional expertise (praxis) and morphed from informing individual practitioners’ decision making to determine their practice through setting guidelines and protocols, from which variation was discouraged. This was crystallised in 1999, when the National Institute for Clinical Excellence (NICE) was established in the UK to remove variation that was perceived to be leading to a ‘postcode lottery’ of practice.3

Nursing too embraced evidence-based practice, even though randomised control trials were hard …