Health Information Science 530 - Evidence Based Health Informatics

"Evidence synthesis is the interpretation of individual studies within the context of global knowledge for a given topic. These syntheses provide a rigorous and transparent knowledge base for translating research in decisions. As such, evidence syntheses can be thought of as the basic unit of knowledge used in tools such a policy brief or clinical practice guideline. In other words, evidence syntheses are the “evidence-base” in evidence-based policy, or evidence-based medicine etc. Essential to all evidence syntheses is the use of explicit and transparent methodology in the formation of the questions they address. The transparent methodology encompasses how studies are identified, selected, appraised, analyzed, and the strength of the evidence assessed to answer the questioned posed."

https://evidencesynthesis.org/what-is-evidence-synthesis/

1. Traditional/narrative.  This type of review critiques and summaries a body of literature and draws conclusions about the topic in question. Cronin, P. BJN, 2008, vol 17, No 1 p. 38-39. 
2. Systematic literature review.  These reviews use a rigorous and well-defined approach to reviewing the literature in a specific subject area. Cronin, P. BJN, 2008, Vol 17, No 1 p.42
3. Scoping reviews aim to map the key concepts underpinning a research area and the main sources and types of evidence available. They provide wide coverage of the literature but can vary enormously in the degree to which they extract, analyse and represent the available evidence. Arksey, H.& O'Malley, 2005, "Scoping studies: towards a methodological framework," http://eprints.whiterose.ac.uk/1618/1/Scopingstudies.pdf.
4. Meta-analysis.  A form of systematic review which is largely a statistical technique.  It takes findings from several studies on the same subject and analyses them using stardardized statistical procedures. Cronin, P. BJN, 2008, Vol 17, No 1 p.42
5. Meta-synthesis.  A non-statistical technique used to integrate, evaluate and interpret the findings of multiple qualitative research studies. Cronin, P. BJN, 2008, Vol 17, No 1 p.42
6. Rapid evidence reviews are used to summarise the available research within the constraints of a given timetable, typically three months or less.  Consequently there are limitations on the extent of the searches and other review activities and should be viewed as provisional appraisals rather than full systematic reviews. Centre for Reviews and Dissemination, 2009,"Systematic Reviews" http://www.york.ac.uk/inst/crd/pdf/Systematic_Reviews.pdf
7. Realist reviews use an iterative protocol and focus on context and process. They are useful for complex policy interventions. Rycroft-Malone, J., McCormack, B., Hutchinson, A. M., DeCorby, K., Bucknall, T. K., Kent, B., ... & Wallin, L. (2012). Realist synthesis: illustrating the method for implementation research. Implementation Science,7(1), 1.

See also Grant, M. J., & Booth, A. (2009). A typology of reviews: an analysis of 14 review types and associated methodologies. Health Information & Libraries Journal, 26(2), 91-108.

Various approaches can be used to organize the review.

1. Themes or Categories - this is popular and allows integration of theoretical and empirical(research) literature.
2. Chronological - can demostrate the emergence of a topic over time.
3. Theoretical/Methodological - this method allows for discussion of the theoretical literatures followed by exploration of methodological literature to indicate why a particle research design might be appropriate for the topic.  Useful when there is little empirical(research) literature. 
4. Theoretical and Methodological in two sections - allows both types to be discussed separately.  May be more of a descriptive rather than a critical review.

Adapted from Cronin, P. BJN, 2008, Vol 17, No 1 p.42