What is evidence based medicine and why do we need it?

Anna Kelsey-Sugg

What does "evidence based medicine" refer to exactly, and why should we care to know?

Evidence Based Medicine (EBM) is the "conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients. The practice of evidence based medicine means integrating individual clinical expertise with the best available external clinical evidence from systematic research” (Sackett et al. 1996).

Research applies scientific method to finding and appraising. It then provides evidence on which to base clinical and policy decisions. Research is the process of asking relevant questions, conducting, or appraising relevant studies, and then harnessing that information in a practical and useable way for those who need to make decisions regarding the care of people.

It is “a movement within the scientific profession based on the use of scientific method, applying rigour to the process of evaluating treatment and management practices. This includes the long-established health traditions that have not yet been subjected to adequate scientific scrutiny” (Wyatt 1996).

Seem confusing? It’s actually quite simple. Let’s take a treatment for back pain as an example of how EBM works:

With a particular treatment, we might find that 90% people with back pain improve within a month. While this sounds positive, an appropriate scientific study would compare those results to what would happen without the treatment, that is, compare treatment outcomes to non-treated outcomes. If a scientific study finds that 9% of people improve within a month anyway, without any treatment, our views on using the treatment will be less positive and more realistic as research shows that treatment is not producing improved overall results.

Further, if we find that people who have that treatment take longer to return to work – perhaps the treatment includes a recommendation of rest, or the treatment further instils in the mind of the individual the idea that something is seriously wrong with them – then that improved level of understanding would lead practitioners to avoid it.

Similarly, researching strategies or interventions that are designed to improve return to work outcomes need to be compared to what occurs when no intervention is in place. Research using a ‘control’ site – one where no intervention was in place – in a similar industry and working under a similar system, allows one to assess if a difference has been made because of the intervention or as part of its natural course.

EBM allows for the results of treatments or interventions to be compared with what would happen if they weren’t implemented. That is, to compare a treatment or intervention to the natural history of a condition or process that is not treated. It aims to increase the use of high quality clinical research in clinical decision making.

Millions of dollars have been spent on interventions that seem to make a difference; however, when rigorously evaluated they have often been found to be ineffective, and worse, at times they increase the problem of work disability.

Avoiding unnecessary treatments and interventions leads to more than just the individual saving time and money. As a result of evidence based medicine and scientific scrutiny, the community benefits through better health and more appropriate treatment.

Sackett, D.L. et al (1996). Evidence based medicine: what it is and what it isn't. BMJ; 312:71-72
Wyatt, M (1996). Research in Work Disability: Background information and discussion paper for Symposium May 25 2006: Setting a National Research Agenda