Literature Reviews

Literature Review Purpose and First Steps

Literature reviews have two purposes in the life of a research project:

1. At the beginning of a project, to ensure an adequate examination of the existing literature on a topic in order to identify a research gap for study.

2. At the conclusion of a project, when results are available, to contextualize the findings from the research project.

Identify and review a couple of narrative reviews on the topic to gain a better big picture understanding.

Literature Review Outline

1.  Create outlines for both the introduction and discussion

   1. The discussion outline will change based on results, but it is good to think about it now.  

2. From these outlines, make list of sub-topics for the literature review.

   1. For an introduction:

      1. Consider a "funnel" of sub-topics

         1. Start with broader reasons why you're working in this area (national guidelines, calls to action, epidemiologic or health economic data about a problem establishing societal burden)

         2. Gradually focus in to lead to your research gap, which in turn should lead to your research question as the last sentence in you introduction

   2. For a discussion:

      1. Update the review on your project - look for new guidelines, new statistics for the problem, etc.

      2. Then look for what work has been done since you designed this project. Are there any new developments in the field? Were your results similar to other work recently published or did they differ? 

      3. Look for possible explanations for some of your findings, especially if unexpected.

3. Determine level of review needed for each sub-topic:  

   1. in-depth, comprehensive understanding of the literature  

   2. a systematic or scoping review or two (e.g., effectiveness of primary care-based interventions for treating back pain) 

   3. the answer to a specific question (e.g., what is the rate back pain complaints in the U.S.?) 

      1. a key reference (ex: the original validation of an instrument)  

4. Create structure for literature review table (i.e., what data needs to be extracted or summarized?). 

Literature Searching

1. Create or identify Reference Manager (Zotero) library for identified literature. 

2. Identify search terms to use

   1. Consider using some of the PICOTS terms

      1. Patient/population of interest

      2. Intervention or exposure of interest

      3. Comparator (alternative intervention, no intervention/exposure, placebo, etc.)

      4. Outcome of interest

      5. Time frame

      6. Setting (ambulatory, hospital, etc.) 

3. Perform Search

   1. PubMed

      1. Use limits and filters wisely in PubMed to avoid excessive numbers of citations

         1. Date filters for more recent literature

         2. "Systematic review," "clinical trial," and "review" filters

      2. See https://learn.nlm.nih.gov/documentation/training-packets/T0042010P/  

      3. Other databases

         1. TRIP Database - results ordered by evidence hierarchy, free version limited to free resources.

         2. Cochrane Library - systematic reviews and the CENTRAL register (curated database of trials) , requires a subscription, often available libraries

Wrapping up the Review

1. Select applicable references for each topic within the review. 

2. Input applicable references into reference manager (Zotero) library. 

3. Complete literature table with annotations from applicable references.  

4. Convert literature table annotations to bullet points or sentences within the outline. 

Additional References

VT Library guide - Systematic Review Help

VT Library guide - Doing a literature search 

YouTube Video - Critical Appraisal

YouTube Video - Critical Appraisal