Address a focused clinical question where review authors systematically search for, identify, select, summarize and critically apraise all of the medical research literature available on a specific topic. Statistical techniques may be used to combine the results of these studies. The authors clearly state the search methods used to locate these studies. It is important to examine the search methods used and decide for yourself if it was broad enough to include all of the relevant studies, and if the studies found were relevant to the clinical question.
Randomized Controlled Clinical Trial (RCT)
An experimental design used for testing the effectiveness of a new medication or a new therapeutic procedure. Individuals are assigned randomly to a treatment group or a control group, and the outcomes are compared. RCT is the most accepted scientific method of determining the benefit of a drug or a therapeutic procedure. It represents the best evidence available, which is integrated into the final decision about the management of a condition by healthcare practitioners in what is called evidence-based healthcare.
an experiment performed on human beings in order to evaluate the comparative efficacy of two or more therapies.
In the Cochrane Library database, the protocol outlines the question that the review authors are addressing, detailing the criteria against which studies will be assessed for inclusion in the review, and describing how the authors will manage the review process.
When results of individual studies are combined to produce an overall statistic.
Brings together information about previously published research on a topic. It provides a critical appraisal of the topic over a period of time. It is helpful in identifying the important literature on a topic. Given the vast amount of scientific literature published, review articles are an excellent tool for researchers wishing to research a topic.
Triad From: The Florida State University College of Medicine Charlotte Edwards Maguire Medical Library. Evidence Based Medicine Tutorial. "Definition of Evidence Based Medicine." 2011. Accessed 8-6-14.
Links for more information:
Frame the question: write out your information need in the form of a question. For example:
Does hand washing among healthcare workers reduce hospital acquired infections?
P = problem/patient/population P = hospital acquired infection
I = intervention I = hand washing
C = comparison intervention C = no hand washing; other solution; masks
O = outcome O =reduced infection
Next, locate sources of evidence. Begin with CINAHL w/Full Text and Medline.
Plan a search strategy: identify the major elements of your question. Translate natural language terms to MeSH terms or subject descriptors. TIP: begin your search with the P and I elements to keep your results broad.
P (Problem/Patient/Population)= hosptial acquired infection
term mapped to database vocabulary: cross infection (Medline MeSH)
cross infection (CINAHL Heading)
I (Intervention/Indicator) = hand washing
term mapped to database vocabulary: handwashing (MeSH)
handwashing (CINAHL Heading)
A simple database search strategy should begin with the P and I, for example:
handwashing and cross infection (using the MeSH or CINAHL terms)
View the results
You may want to narrow your search with terms for the Comparison, Outcome or type of study.Or you may want to view your results and full text articles to see what is reported there.
Tips for narrowing your search:
1. From the online thesaurus, choose a narrower, more specific term for your topic. For example, search the Medline thesaurus (MeSH) for infection, and notice the narrower term, catheter-related infections.
2. Narrow with subheadings: restrict your results to a subtopic of interest. For example: in Medline MeSH) handwashing/standards
3. Apply LIMITS: limit by age group if appropriate; limit by publication type--meta-analysis, practice guideline; language; date of publication; evidence based; systematic reviews; research or peer-reviewed (in CINAHL);
Tips for expanding your search:
1. Add search terms (synonyms) that you find in the records of your initial search.
2. Truncation: use the * at the end of the root of a term to search for plurals: teen* retrieves teens, teenager, teenagers
3. In the MeSH thesaurus, or in CINAHL Headings, view the tree structure of terms and EXPLODE to retrieve the narrower terms.
4. View the list of references for additional relevant articles.
Filtered Resources appraise the quality of studies and often make recommendations for practice.
Systematic Reviews and Meta-Analyses
Authors of systematic reviews ask a specific clinical question, perform a comprehensive search of the literature, eliminate poorly done studies and make practiced recommendations based on the well-done studies.
A meta-analysis is a systematic review that combines the results of all the studies into one statistical analysis of results.
Critically Appraised Topics
Authors evaluate and synthesize multiple research studies.
Critically Appraised Individual Articles
Authors evaluate individual research studies.