(Adapted from Wilczynski, N. L.et al. (2005))
When dealing with EBP, you will often hear about the “best” evidence. This means two things:
Imagine you had a patient with recurring, painful acne. What kind of research would you seek to help deliver a treatment: a systematic review of several randomized controlled trials of treatments for this condition, a single case study of a patient experiencing similar symptoms, or your colleague’s third cousin, who once mentioned that “chocolate causes acne”?
These are all forms of evidence—even the last one!—but something like a systematic review, which amasses data from numerous studies to create generalizable results, will provide the broadest view of the evidence on your patient’s condition and help you devise an evidence-based treatment plan.
However, sometimes the very high levels of evidence aren’t available. As you seek higher levels of evidence, they become less common, as shown in the pyramid above. With an especially narrow topic, or one about a new phenomenon, a single case study may be the best you can find. Additionally, for some types of questions—etiology or harm, for instance—it may not be ethically possible for a randomized controlled trial to exist.
A collection of databases providing access to systematic reviews and clinical trials in healthcare, supporting evidence-based decision-making and research in medicine and health.
This collection of six databases provides evidence-based clinical information for healthcare providers. The Cochrane Database of Systematic Reviews (CDSR) contains protocols and reviews of interventions, diagnostic tests, and methodology. The Database of Abstracts of Reviews of Effects (DARE) covers a broad range of health related interventions and thousands of abstracts of reviews in fields as diverse as diagnostic tests, public health, health promotion, pharmacology, surgery, psychology, and the organization and delivery of health care. The Cochrane Central Register of Controlled Trials (CENTRAL) brings together abstracts of published articles from EMBASE, MEDLINE, and other published and unpublished sources. The Cochrane Methodology Register (CMR) is a bibliography of publications that report on methods used in the conduct of controlled trials. The Health Technology Assessment (HTA) database brings together details of completed and ongoing health technology assessments (studies of the medical, social, ethical, and economic implications of healthcare interventions) from around the world. The NHS Economic Evaluation Database (EED) contains information about both costs and effects that are essential to making evidence-based decisions about competing healthcare interventions throughout the world.