In clinical practice caring for patients generates many questions about diagnosis, prognosis, and treatment that challenge health professionals to keep up to date with the medical literature. A study of general practitioners in North America found that two clinically important questions arose for every three patients seen.1 The challenge in keeping abreast of the medical literature is the volume of literature. General physicians who want to keep up with relevant journals face the task of examining 19 articles a day 365 days a year.2

One approach to meeting these challenges and avoiding clinical entropy is to learn how to practise evidence based medicine. Evidence based medicine involves integrating clinical expertise with the best available clinical evidence derived from systematic research.3 Individual clinical expertise is the proficiency and judgment that each clinician acquires through clinical experience and practice. Best available clinical evidence is clinically relevant research which may be from the basic sciences of medicine, but especially that derived from clinical research that is patient centred, that evaluates the accuracy and precision of diagnostic tests and prognostic markers, and the efficacy and safety of therapeutic, rehabilitative, and preventive regimens. This paper focuses on what evidence based medicine is and how it can be practised by busy clinicians.

The practice of evidence based medicine is a process of lifelong self directed learning in which caring for patients creates a need for clinically important information about diagnoses, prognoses, treatment, and other healthcare issues. The box at the bottom of the next page illustrates the five steps necessary to the practice of evidence based medicine.