ABSTRACT
The concept of 'evidence-based medicine' (EBM) has received much attention in recent years. The development of EBM is inextricably linked with the landmark publication of Effective Care in Pregnancy and Childbirth by Ian Chalmers in 1989. Educational processes and learning environments need to be created in which doctors can prepare themselves for their future role. Chance and bias are straightforward issues. A confounding variable may be considered as a particular type of bias, and several biases may occur in a single study. It is helpful to separate out studies that are observational (and are therefore hypothesis-forming) from those that are analytical (and therefore hypothesis-testing). Observational studies are case reports and case studies, and cross-sectional studies and correlational studies. Analytical studies are case-control studies and cohort studies. Medline is an electronic medical reference database available free to all members of the British Medical Association. Clinical guidelines are produced at a prodigious rate in both primary and secondary care.
