- Trisha Greenhalgh, Senior lecturer
- Joint Department of Primary Care and Population Sciences, University College London Medical School/Royal Free Hospital School of Medicine, Whittington Hospital, London N19 5NF
Should be answered in qualitative, as well as quantitative terms
The growing interest in evidence based medicine among practising clinicians1 has prompted doctors in every specialty to ask themselves, “to what extent is the care of my patients evidence based?” The search is on for a means of answering this question that is achievable, affordable, valid, reliable, and responsive to change.
Evaluating one's own performance is the final step in the five stage process of traditional evidence based practice. The first four steps are: to formulate for each chosen clinical problem an answerable question, to search the medical literature and other sources for information pertaining to that question, to assess the validity (closeness to the truth) and usefulness (relevance to the problem) of the evidence identified, and to manage the patient accordingly.2
Several papers have been published3 4 5 and many more are being written whose stated objective is “to assess whether my/our clinical practice is evidence based.” Most describe prospective surveys of a consecutive series of doctor-patient encounters in a particular specialty, in which the primary intervention for each patient was classified by the doctors (and in some cases verified by an independent observer) according to whether it was based on evidence from randomised controlled trials, convincing non-experimental evidence, or inadequate evidence.
Such surveys have generated the widely quoted figures that 82% of interventions in general medicine,3 81% of interventions in general practice,4 and 62% of interventions in psychiatry5 are evidence based. Questionnaire surveys of what doctors say they do in particular circumstances are starting to add to this literature.6 The public may soon be offered a “league table” of specialties ranked according to how evidence based they have shown themselves to be.
Figures produced in the early …