Types of Literature Reviews

A Narrative or Traditional Literature Review is conducted as preliminary part of a research study. The purpose is to critique and to summarize the current literature that exists on the research topic. The literature review helps to understand the topic and can identify inconsistencies and gaps in the literature, helping to justify why the research question is worth studying. 

To conduct a narrative or traditional literature review a researcher should "systematically search, critique and combine the literature to demonstrate a gap in the existing research base" while demonstrating "their understanding of both the research and the methods previously used to investigate the area" (Aveyard, 2010).

The purpose of a literature review may slightly differ depending on what kind of research is being conducted. 

Purpose in Quantitative:

• helps to "direct the planning and execution of a study" (Grove, 2015, p.163)
• provides background and reasons why the question is worth studying
• conducted before the study  AND sometimes again after  the study  in order to capture any literature published while study was being conducted. Additional sources may also help researchers interpret the research findings (Grove, 2015, p.163).

Purpose in Qualitative: 

• provides background and reasons why the questions is worth studying
• may not be extensive, attempt to manage expectations and bias in data collection, analysis and interpretation of findings
• no additional review, post study (Why? There may not be a lot of literature on topics being studied as qualitative often looks at topics that little is is known) (Grove, 2015, p.164). 
• length and depth of the review will also depend on the qualitative methodology being studied

Knowledge Syntheses are reviews that are research projects themselves. The literature search is done systematically, and seeks to "evaluate and interpret all available research evidence relevant to a particular question" (Glasziou, 2001).

Knowledge synthesis can be defined as “…the contextualization and integration of research findings of individual research studies within the larger body of knowledge on the topic. A synthesis must be reproducible and transparent in its methods, using quantitative and/or qualitative methods... Realist syntheses, narrative syntheses, meta-analyses, meta-syntheses and practice guidelines are all forms of synthesis.” (Canadian Institutes of Health Research. (2016, July 28). Knowledge Translation. Retrieved September 15, 2019 from http://www.cihr-irsc.gc.ca/e/29418.html. )

Types of Knowledge Syntheses

Systematic Review

• research study design that draws conclusions by analyzing all the single studies conducted on a topic 
• comprehensive - looks for all the published and unpublished studies related to the research question
• uses a rigorous and well-defined method for searching, evaluating and synthesizing studies

Example: systematic review

Meta-Analysis

• similar to a systematic review  but statistically combines the results of quantitative studies to provide a more precise effect of the results
• research study design that draws conclusions by analyzing all the single studies conducted on a topic 
• comprehensive - looks for all the published and unpublished studies related to the research question
• uses a rigorous and well-defined method for searching, evaluating and synthesizing studies

Example: meta-analysis

Scoping Review

• "... addresses an exploratory research question aimed at mapping key concepts, types of evidence, and gaps in research related to a defined area or field by systematically searching, selecting and synthesizing existing knowledge." (Colquhoun, HL et al., 2014)
•  often happens before another type of study such as a primary research study or a systematic review is conducted; informs further research

Example: scoping review

Integrative Review

• "The integrative review method is an approach that allows for the inclusion of diverse methodologies (i.e. experimental and non-experimental research)" (Whittemore et al., 2005).
• "integrative reviews present the state of the science, contribute to theory development, and have direct applicability to practice and policy" (Whittemore et al, 2005).

Example: integrative review

Aveyard, H. (2010). Doing a literature review in health and social care: A practical guide (2nd ed.). Berkshire, Great Britain: Open University Press.

Canadian Institutes of Health Research. (2016, July 28). Knowledge Translation. Retrieved September 15, 2019 from http://www.cihr-    irsc.gc.ca/e/29418.html. 

Colquhoun, H. L., Levac, D., O'Brien, K. K., Straus, S., Tricco, A. C., Perrier, L., . . . Moher, D. (2014). Scoping reviews: Time for clarity in         definition, methods, and reporting. Journal of Clinical Epidemiology, 67(12), 1291-1294. doi:10.1016/j.jclinepi.2014.03.013.

Glasziou, P. (2001). Systematic reviews in health care: A practical guide. New York, NY: Cambridge University Press.

Grove, S., Gray, J. & Burns, N. (2015). Understanding Nursing Research: Building an Evidence-Based Practice. St. Louis, Missouri: Elsevier     Saunders. 

Whittemore R. & Knaf K. (2005). The integrative review: updated methodology.  Journal of Advanced Nursing, 52(5). http://dx.doi.org/10.1111/j.1365-2648.2005.03621.x