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Evidence-Based Research

Primary Literature

Examples with Medline 


Type of Question


Type of Study/Methodology



Therapy: information needed about treatments (effectiveness, cost, etc.)  

Randomized Controlled Trial 

Randomized Controlled Trial [PT]
double [TW] and blind [TW] 

Diagnosis: information needed about a diagnostic test (sensitivity, accuracy, etc.)

Controlled Trial

Sensitivity and Specificity [MH] 
Diagnosis [SH] 

Prognosis: information needed about the course of the disease over time, expected complications, etc.  

Cohort Studies
Case Control
Case Series 

Cohort Studies [MH]
Prognosis [MH]
Survival Analysis [MH] 

Etiology/Harm: information needed about causes of disease or contributing factors of disease

Cohort Studies

Cohort Studies [MH]
Risk [TW] 

Prevention: information needed about the prevention of disease (immunization, social factors, etc.)

Randomized Controlled Trial
Cohort Studies  

Randomized Controlled Trial [PT]
Cohort Studies [MH] 
Prevention and Control [SH] 

Quality Improvement: information needed about clients' and health professionals' experiences and concerns 

Randomized Controlled Trial

Randomized Controlled Trial [PT]
Practice Guideline [PT] 
Consensus Development Conference [PT]  

(Abbreviations: MH=Medical Subject Heading; PT=Publication Type; SH=Subheading; TW=Text Word)


This secondary literature synthesizes, filters, and evaluates the primary research literature. Dissemination and incorporation of valid clinical research findings into medical practice is the ultimate goal. Examples with Cochrane, PubMed, Medline

  • Systematic Reviews
  • Meta-Analyses
  • Critically Appraised Topics
  • Decision Analyses/Decision Tools
  • Evaluated Bibliographic Databases
  • Practice Guidelines
  • Consensus Development Reports

Filtered or


How To Find This Type of Information


-differ from traditional review articles in that conclusions are evidence-based rather than commentary

-start with a clearly articulated question

-use explicit, rigorous methods to identify, critically appraise, and synthesize relevant studies

-appraise relevant published and unpublished evidence before combining and analyzing data

-include description of how primary data sources are identified

-assess individual studies for validity

*Cochrane Database of Systematic Reviews

Review [PT] AND medline [TW]
(Quantitative OR Systematic OR Methodologic) AND (Review OR Overview)

*In PubMed:

Clinical Queries "Systematic Review" is available as a limit option.


-specific methodologic and statistical technique for combining quantitative data

-type of systematic overview

*Cochrane Database of Systematic Reviews

Meta-analysis [PT]
meta-anal* [TW] OR
metaanal* [TW]


-gather, appraise, combine evidence systematically

-include statements designed to assist practitioner and patient decisions

-developed by professional groups, government agencies, local practices

-include a structured abstract: objective, option, outcomes, evidence, values, benefits/harms/costs, recommendation, validation, sponsors

*National Guideline Clearinghouse

*Agency for Healthcare Research and Quality

*US Preventive Services Task Force Recommendations


-scan literature for clinically relevant studies

-critically appraise the studies

-provide commentary on strength of study and clinical significance

-provided in a one-page format

*Critically Appraised Worksheet and Guidelines

*CATmaker software from CEBM


-studies that analyze decisions faced by clinicians for an individual patient, about clinical policy, or a global health care policy

-application of explicit, quantitative methods to analyze decisions under conditions of uncertainty

-risks and benefits of a decision are made fully explicit

-decision tree is included


Decision Support Techniques [MH]

Cost-Benefit Analysis [MH]

decision analysis [TI]

(Abbreviations: MH=Medical Subject Heading; PT=Publication Type; SH=Subheading; TW=Text Word)