Subject Guides: Evidence Based Medicine: Acquire the Best Evidence

Finding Evidence: The Evidence Pyramid

The Evidence Pyramid represents how to efficiently search for the best evidence. Begin by searching resources at the top of the pyramid and work your way down as needed.

Filtered Information: These resources summarize and appraise the quality of evidence from existing studies and often make recommendations for applying it to practice. Filtered resources include: systematic reviews or meta-analyses, critically-appraised topics (syntheses), evidence-based clinical practice guidelines, critically-appraised individual articles (synopses).

Unfiltered Information: Filtered resources are not always available on every topic. Searching the primary literature may be necessary. PubMed/Medline, PsycINFO, and CINAHL provide "clinical queries" or EBM search filters that can be used within a regular search to locate high-level evidence.

Systematic Reviews

A systematic review summarises the results of available carefully designed healthcare studies (controlled trials) and provides a high level of evidence on the effectiveness of healthcare interventions. Judgments may be made about the evidence and inform recommendations for healthcare (Cochrane Consumer Network). Sladen resources to locate systematic reviews are listed below.

Cochrane Database of Systematic Reviews (CDSR)
CDSR includes systematic reviews and protocols produced by Cochrane Review Groups.
PubMed with Clinical Queries
PubMed is a bibliographic database providing access to the MEDLINE database and other life science journals. Search for systematic reviews by using the Clinical Queries filter.
CINAHL with Clinical Queries
Access the "Limits" section within CINAHL to apply a Clinical Query to your search. Use "Review - High Sensitivity" or "Review - High Specificity" to limit results to systematic reviews and meta-analyses.
Health Evidence
From McMaster University in Canada, this is a searchable database of quality-appraised systematic reviews evaluating public health interventions in prevention, health protection, and health promotion. Free registration is required.

Syntheses

Syntheses represent critically-appraised topics and evidence-based guidelines. Syntheses are typically point-of-care tools that are updated regularly following extensive literature searches for the best evidence. Sladen Library resources to help locate syntheses are listed below.

UpToDate This link opens in a new window
UpToDate provides evidence-based summaries on a variety of clinical topics, drug information powered by LexiComp, and a collection of medical calculators.

Mosby's Evidence-Based Nursing Monographs
Current, relevant evidence about common clinical problems, written for nurses by nurse experts. Includes summaries of key studies that are tagged by levels of evidence.

Clinical Practice Guidelines

The National Guideline Clearinghouse website was discontinued in 2018. Please visit this Sladen Blog post for tips on how to locate clinical practice guidelines.

Synopses

Synopses represent critically-appraised journal articles. They provide quick summaries of individual studies. Sladen resources to locate synopses are listed below.

ACP Journal Club
Features summaries of the best new evidence in internal medicine from over 130 clinical journals. ACP Journal Club is part of Annals of Internal Medicine.
Evidence-Based Medicine (Journal)
Evidence-Based Nursing (Journal)
Evidence-Based Mental Health (Journal)
EvidenceAlerts
Quality articles from over 110 clinical journals are selected by research staff and then rated for clinical relevance and interest by an international group of physicians. Includes a searchable database of the best evidence from the medical literature and an email alerting system. Requires free registration.
OTseeker
OTseeker is a database that contains abstracts of systematic reviews and randomized controlled trials relevant to occupational therapy.

PEDro This link opens in a new window
PEDro is the Physiotherapy Evidence Database, developed to give rapid access to bibliographic details and abstracts of randomised controlled trials, systematic reviews and evidence-based clinical practice guidelines in physiotherapy.

Studies

When no systematic reviews, synopses, syntheses, or guidelines exist for a topic, search for original studies in the medical literature. Resources to use for searching the medical literature are listed below.

PubMed This link opens in a new window
PubMed provides access to the MEDLINE database. It covers the fields of biomedicine, health, life sciences, behavioral sciences, chemical sciences, and bioengineering.
Medline / Ovid This link opens in a new window
MEDLINE is the National Library of Medicine's premier bibliographic database providing information from the fields of medicine, nursing, allied health, dentistry, veterinary medicine, the health care system and the pre-clinical sciences.
Embase This link opens in a new window
An international biomedical literature database that indexes more than 8,500 peer-reviewed journals for users looking for drug, medical device, and disease-related information.
PsycINFO This link opens in a new window
Produced by the American Psychological Association, this database provides abstracts and citations to scholarly literature in the psychological, behavioral, and social health sciences.
CINAHL This link opens in a new window
The CINAHL database (Cumulative Index to Nursing and Allied Health Literature) is the premier index for the literature of nursing and allied health.

Cochrane Central Register of Controlled Trials
CENTRAL is a database of clinical trials that serves as the best available resource for those preparing and maintaining systematic reviews or searching for trials. It includes citations that may not be indexed in MEDLINE, EMBASE, or other bibliographic databases, citations published internationally in many languages, and citations that are available in conference proceedings or other hard to access sources.

Web of Science This link opens in a new window
This database provides access to the Science Citation Index Expanded from 2002-present. SCIE covers over 150 disciplines including medicine, biology, life sciences, and technology.

Background Information / Expert Opinion

This final step in the pyramid refers to resources such as review articles and textbooks. Information obtained from these sources usually lack level of evidence ratings and are updated less frequently than other sources.