Skip to Main Content


Good doctors use both individual clinical expertise and the best available external evidence, and neither alone is enough. Without clinical expertise, practice risks becoming tyrannized by evidence, for even excellent external evidence may be inapplicable to or inappropriate for an individual patient. Without current best evidence, practice risks becoming rapidly out of date, to the detriment of patients.

Sacket et al, 1996


Evidence-based medicine (EBM) is “the conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients.”1,2 The phrase evidence-based medicine was developed by a group of physicians at McMaster University in Hamilton, Ontario, in the early 1990s.1,3 EBM is a combination of clinical expertise and best evidence, as eloquently stated by Sacket and colleagues in the above quotation.1 The EBM definition has two basic components: the first is “the conscientious, explicit, and judicious use,” which, in trauma, applies to split-second decision in the face of an immense variety of unexpected clinical scenarios. The time pressure and the irreversibility of many surgical procedures enhance the anxiety of decision making.4

The second component of the EBM definition is “best evidence.” What constitutes “best evidence”? Best evidence is “clinically relevant research,”1 which can both invalidate previously accepted procedures or replace them with new methods that are more powerful, efficacious, safe, and cost containing.5 In simple words, it comes down to “How does the article I read today changes (or not) how I treat my patients tomorrow?”6

Searching for evidence usually starts with the formulation of a searchable clinical question. For this purpose, the PICO framework is very helpful.7 PICO stands for patient (P), intervention (I), comparator (C), and outcome (O). When searching for evidence, or determining whether the most recently read article applies to the patient in front of you, quickly define whether the PICO observed in the study are similar enough to allow application of the study results to the individual patients in your practice.

Once you determine whether a published report applies to your practice, critical appraisal is the next step. Critical appraisal of the internal and external validity of a scientific report is essential to filter the information that can improve individual patient care as well as contribute to an efficient, high quality health care system. Critical appraisal of an article requires an inquisitive and skeptical mindset combined with a basic understanding of scientific and statistical methods.8 Many would say that scientific and statistical methods are only for researchers. Yet these methods are essential in becoming excellent consumers of research and EBM practitioners. This chapter will provide a basic review of methods for searching, critically appraising, and applying evidence, including an introduction to statistical topics essential to a reliable interpretation of trauma literature.


Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.