What are the limitations of EBM?
The examination of the concepts and practice of EBM by clinicians and academics has led to negative as well as positive reactions. The ensuing discussion and debate has reminded us of 3 limitations that are universal to science (whether basic or applied) and medicine (the shortage of coherent, consistent scientific evidence; difficulties in applying any evidence to the care of individual patients; barriers to any practice of high quality medicine). The debate has also identified 3 limitations that are unique to the practice of EBMi,ii. First, the need to develop new skills in searching and critical appraisal can be daunting, although (as we pointed out above) evidence-based care can still be applied if only the former has been mastered and directed toward pre-appraised resources. Second, busy clinicians have limited time to master and apply these new skills, and the resources required for instant access to evidence are often woefully inadequate in clinical settings. Finally, evidence that EBM "works" has been late and slow to come.
On the other hand, the ensuing discussion and debate has clarified some "pseudo-limitations" that arise from misunderstandings of the definition of EBM. An examination of the definition and steps of EBM quickly dismisses the criticisms that it denigrates clinical expertise, is limited to clinical research, ignores patients' values and preferences, or promotes a cookbook approach to medicine. Moreover, it is not an effective cost-cutting tool, since providing evidence-based care directed toward maximizing patients' quality of life often increases the costs of their care and raises the ire of health economistsiii. In addition, the self-reported employment of the "searching" mode by a great majority of front line GPs dispels the contention that EBM is an ivory tower concept. Finally, we hope that the rest of this book will put to rest the concern that EBM leads to therapeutic nihilism in the absence of randomized trial evidence.
- Sackett DL, Rosenberg WMC, Gray JAM, Haynes RB, Richardson WS: Evidence based medicine: what it is and what it isn't. BMJ 1996;312:71-2.
- Straus SE, McAlister FA: The limitations of evidence-based medicine. In press.
- Maynard A: Evidence-based medicine: an incomplete method for informing treatment choices. Lancet 1997;349:126-8