Can clinicians actually practice EBM?
First of all, do full-time clinicians really recognize working in these modes? It appears so. In a survey of UK GPs (in which responders were more likely to hold MRCP certification), the great majority reported practicing at least part of their time in the "searching" mode, using evidence- based summaries generated by others (72%) and evidence-based practice guidelines or protocols (84%)i. On the other hand, far fewer claimed to understand (and be able to explain) the "appraising" tools of NNTs (35%) and confidence intervals (20%). Finally only 5% believed that "learning the skills of evidence-based medicine" (all five steps) was the most appropriate method for "moving from opinion-based medicine to evidence-based medicine.1"
Second, even if they recognize these modes, can they actually get at the evidence quickly enough to consider it on a busy clinical service? Again, it appears so, but examples are few. When a busy (180+ admissions per month) in-patient medical service brought electronic summaries of evidence previously appraised either by team members ("CATs"2) or by the summary journals3 to working rounds, it was documented that, on average, the former could be accessed in 10 seconds and the latter in 25 seconds. Moreover, when assessed from the viewpoint of the most junior member of the team caring for the patient, this evidence changed 25% of their diagnostic and treatment suggestions and added to a further 23% of them.
Third, even if they can get at it, can clinicians actually provide evidence-based care to their patients? Again, it appears so from audits carried out on clinical services that attempt to operate in the searching and appraising modes. The first of these examined the evidence-base for the primary interventions applied to the primary diagnoses of consecutive patients on an in-patient medical service and documented that 82% of them were evidence-based (53% based on randomized trials or systematic reviews of randomized trials and 29% based on convincing non-experimental evidence)ii. Similar results have been obtained from audits of psychiatriciii, surgicaliv, pediatricv and generalvi practice.
- As it happens, this latter result is surprisingly close to a 1981 guessimate by the authors of the McMaster University readers guides that only 6% of clinicians would be likely to master and use critical appraisal skills). [Sackett DL, Haynes RB, Tugwell P, Neufeld VR, personal communication, 1999.]
- CATs, or Critically-Appraised Topics, are discussed in detailed on page 87.
- Best Evidence, described on page 32 - 33.
- McColl A, Smith H, White P, Field J: General practitioners' perceptions of the route to evidence based medicine: a questionnaire survey. BMJ 1998;316:361-5
- Ellis J, Mulligan I, Rowe J, Sackett DL: Inpatient general medicine is evidence based. Lancet 1995;346:407-10. This whole series of studies are summarised and updated by Andrew Booth on his excellent website: http://www.shef.ac.uk/~scharr/ir/percent.html
- Geddes JR, Game D, Jenkins NE, Peterson LA, Pottinger GR, Sackett DL: In-patient psychiatric care is evidence-based. Proceedings of the Royal College of Psychiatrists Winter Meeting. Stratford, UK. January 23-5, 1996.
- Howes N, Chagla L, Thorpe M, McCulloch P: Surgical practice is evidence based. Br J Surg 1997;84:1220-3
- Kenny SE, Shankar KR, Rintala R, Lamont GL, Lloyd DA : Evidence-based surgery: interventions in a regional paediatric surgical unit. Arch Dis Child 1997;76:50-3
- Gill P, Dowell AC, Neal RD, Smith N, Heywood P, Wilson AE: Evidence based general practice: a retrospective study of interventions in one training practice. BMJ. 1996;312:819-21.