Skip to main content

Evidence-based Medicine: Acquire the Evidence

An interdisciplinary guide to EBM resources.

Step 2

AcquireFind the best available evidence by searching the literature.

Levels of Evidence

The EVIDENCE PYRAMID is often used to illustrate the development of evidence. At the base of the pyramid is animal research and laboratory studies - this is where ideas are first developed. As you progress up the pyramid the amount of information available decreases in volume, but increases in relevance to the clinical setting.


http://libraryguides.unh.edu/health-literacy.  Adaptation of the Evidence Pyramid Diagram developed by the Medical Research Library of Brooklyn, SUNY Downstate Medical Center.

Sources of research may be either pre-appraised (summaries), primary literature or more anecdotal.

Type of Study Where to Find it
Systematic Reviews or Meta-analysis Cochrane Library, MEDLINE, EMBASE
Critically-Appraised Topics DynaMed, UpToDate
Critically-Appraised Articles ACP Journal Club
Randomized Controlled Trials Original articles (search MEDLINE, EMBASE)
Cohort Studies Original articles (search MEDLINE, EMBASE)
Case-Controlled Studies etc. Original articles (search MEDLINE, EMBASE)
Background Info/Expert Opinion Books, editorials

Clinical Filters

What type of question are you asking and which would be best to support the evidence?

Type of Question Type of Study/Methodology to Look at
Therapy

Double-Blind Randomized Controlled Trial; Systematic Review/Meta
Analysis of RCT

Diagnosis Controlled Trial; Systematic Review/Meta Analysis of
Controlled Trial
Harm Cohort studies
Prognosis Cohort Studies; Case control, case studies
Etiology Cohort studies
Prevention Randomized Controlled Trial; Cohort studies
Quality Improvement Randomized Controlled Trial
Quality of Life Qualitative Study
Cost Effectiveness Economic Evaluation
Clinical Exam Prospective, blind comparison to gold standard

Database Filters