The evidence based medicine movement, which arose in McMaster University in Canada in the 1990s, has steadily grown to influence health-care professions other than medicine where it is recognised as evidence based practice. It is now widely accepted as a fundamental tenet where health care is available in developed country settings and the prevailing medical system is one of western medicine. The importance of evidence in defining policy and practice in the UK health system and others is acknowledged and, probably, enduring
