Introduction

“Any doctor not fulfilling the standards and quality of care in the appropriate treatment that are set out in these Clinical Guidelines, will have this taken into account if, for any reason, consideration of their performance in this clinical area is undertaken.” Department of Health, 1999.1

Evidence based guidance arguably offers the most trustworthy advice available to clinicians concerning medical management. Their authoritative status may explain why clinical guidelines are sometimes prefaced with vague warnings that link guideline compliance with accountability. But how authoritative can guidelines actually be, and does evidence based guidance entirely supplant clinical discretion?

The legal status of evidence based guidance is examined, including whether guidelines from the National Institute for Clinical Excellence (NICE) should be understood to carry special importance in helping courts to decide whether or not allegations of negligence should be upheld.

What is evidence?

Evidence is a generic notion of great importance to many practices and enquiries. Cardinal to spying, journalism, historical and scientific research, and the practice of medicine, semantically the term bundles together two approaches to supporting belief, perception, and understanding. Whether evidence refers to marks or indications conspicuous to an observer, to reasoning and judgment about such indications, or to analysis of data arising from experiments, evidence leads on to and supports hypotheses and conclusions, however provisional and conditional.

Evidence—and the more recently minted compound term “evidence based”—refers to reliable observational, inferential, or experimental information forming part of the grounds for upholding or rejecting claims or beliefs. Evidence based medicine (EBM) has not developed a new concept of evidence2; its major contribution lies in the emphasis it places on a hierarchy of evidential reliability, in which conclusions related to evidence from controlled experiments are accorded greater credibility than conclusions grounded in other sorts of evidence. Since studies underpinning most medical …