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Introduction to Literature Search

This guide is intended to provide you with the basic skills necessary to search for literature. The skills are presented broadly and can be applied across all databases.

Finding the Right Article for your Research Needs

When looking for articles in journals, it is important to keep in mind that there are many types of articles. They can serve different purposes and therefore compliment your research and writing in different ways.

You can use this chart to help you decide what type of article is best for your research needs. This chart is not exhaustive and does not include every type of article, but some of the most common types.

Common Types of Articles

Article Type Definition Advantages/Disadvantages

Systematic Reviews

Systematic reviews focus on a clinical topic and answer a specific question. An extensive literature search is conducted to identify studies with sound methodology. The studies are reviewed, assessed for quality, and the results summarized according to the predetermined criteria of the review question. Systematic reviews are considered more reliable and accurate than individual studies. They are considered a highly evidence-based resource. However, they tend be very long and can take some time to read.
Meta-Analysis

A meta analysis is done using a method for statistically gathering quantitative studies to develop a single conclusion that has great statistical power 

A meta analysis will provide a conclusion that is statistically stronger than any single study because of its use of increased numbers of subjects, diversity of subjects or accumulated effects and results. However, some authors will have a difficult time identifying appropriate studies since not all studies provide adequate data for inclusion and analysis. A meta analysis also requires advanced statistical techniques. 

Critically Appraised Topics CAT's are a brief evidence based critical appraisal of one or two relevant studies to answer a clinical question. A CAT provides a short and brief review.  However, it is a less rigorous version of a systematic review. It is a single piece of evidence that is summarized and should not be considered a complete representation of the entire body of evidence on a clinical issue.
Randomized Controlled Trials RCT's are clinical trials based on random subject assignment to an experimental or control group. They are considered the gold standard for measuring an intervention's impact across many diverse fields.  Well-designed RCTs are superior to other study designs in estimating an intervention’s true effect. 
Cohort Studies Cohort studies have a control group where a group of people with something in common (a cohort) are followed. This group is compared to another group with similar characteristics/circumstances, with the exception of the factor being investigated. Cohort studies are observational and not as reliable as randomized controlled studies, since the two groups may differ in ways other than in the variable under study.  
Case Reports  Case reports are a collection of reports on the treatment of individual patients or a report on a single patient.  They have little statistical validity because they are individual reports of cases and use no control groups to compare outcomes. 
Expert Opinion  Expert opinion is an authoritative opinion of an expert.  An expert opinion provides anecdotal information from someone with clinical experience which can be valuable; however it is not considered to be evidence-based information.  

More Study Designs

Evidence Pyramid

                                                                                             

      

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