Different Types of SECONDARY RESSEARCH (Reviews)

The common types of literature reviews will be explained in the pages of this section.

• Systematic literature reviews

• Critically Appraised Topic (CAT)

• Rapid Reviews

• Narrative or traditional literature reviews

• Scoping reviews NB these reviews have a slightly different focus and aim to summarise whats research is out there rather than answer a specific clinical question.

These are not the only types of reviews of literature that can be conducted. Often the term "review" and "literature" can be confusing and used in the wrong context. Grant and Booth (2009) attempt to clear up this confusion by discussing 14 review types and the associated methodology, and advantages and disadvantages associated with each review.

Grant, M. J. and Booth, A. (2009), A typology of reviews: an analysis of 14 review types and associated methodologies. Health Information & Libraries Journal, 26, 91–108. doi:10.1111/j.1471-1842.2009.00848.x

Understanding different types of reviews IMPACT RATING (IR) 9/10

The following list gives you a rough estimate of time for each review depending on the specific circumstances of the review.  The list also goes from most basic to more complex with greater rigor.  Please note that this ranking is based on the general understanding of the quality and rigor associated with each review type. The timeframes mentioned are rough estimates and can vary. 

Systematic Review: There are different types.  Consider these the pinnicle of research, clear, transparent with specific steps

(Meta-analysis) 4-12 months DIFFICULTY RATING (DR) 9/10    

Combines data from multiple independent studies addressing the same question. Requires empirical evidence in the form of randomised controlled trials. Meta-Analysis are undertaken by groups of researchers as the numbers of papers reviewed is very large. Meta- analysis are useful for providing a better estimate of the impact or effectiveness of an intervention, meta-analysis are used in health, sciences and humanities.

(Cochrane Reviews) 12-24 months DIFFICULTY RATING (DR) 9/10

Cochrane Reviews are systematic reviews primary research in human health care and health policy, and are internationally recognised as the highest standard in evidence-based health care. They investigate the effects of interventions for prevention, treatment and rehabilitation. They also assess the accuracy of a diagnostic test for a given condition in a specific patient group and setting.

(Meta-synthesis) 8-16 weeks DIFFICULTY RATING (DR) 7/10   

Examines, interprets and integrates findings of several qualitative studies using qualitative methods. Meta-synthesis are used in research looking at theory development. Meta-synthesis are used for clarifying concepts and patterns, and refining existing models and theories.

Critically Appraised Topic (CAT) 2-6 weeks DIFFICULTY RATING (DR) 7/10

A Critical Appraisal of a Topic (CAT) is a systematic and structured process used to evaluate the validity, relevance, and reliability of research studies on a specific topic. It involves carefully analysing and appraising the key components of a study to determine its overall quality and applicability to clinical practice. CATs are useful when you havent got the time required to perform a Systematic review.  They are also useful when knowledge in the area is emerging or not abundant.

Rapid Review  DIFFICULTY RATING (DR) 6.5/10  

Rapid reviews are undertaken to help support time-sensitive decision making. Standard systematic review procedures are adapted by removing or modifying some steps. These reviews are undertaken to quickly find information on a topic to support a project or decision making. Rapid reviews are useful in delivering answers in a shortened time frame.

Scoping Reviews DIFFICULTY RATING (DR) 7/10

A scoping review is quite similar to a Systematic literature review. The key difference being that there are no restrictions on the materials resourced. The purpose of the scoping review is to find ALL the materials on the topic. When undertaking a scoping review it is important to systematise your search strategies to ensure you can replicate your searches and to attend to any gaps that appear in results. 

When reading and sorting the results, again, apply some of the measures used in a systematic review so that your search results are sorted by key themes and well organised. 

Traditional Literature / Narrative reviews DIFFICULTY RATING (DR) 4/10

Narrative or Traditional literature reviews critique and summarise a body of literature about the thesis topic.  The literature is researched from the relevant databases and is generally very selective in the material used. The criteria for literature selection for a narrative review is not always made open to the reader. These reviews are very useful in gathering and synthesising the literature. The principle purpose of a narrative review is the give the author and reader a comprehensive overview of the topic and to highlight significant areas of research. Narrative reviews can help to identify gaps in the research and help to refine and define research questions. Where a narrative approach differs from a systematic approach is in the notation of search methods criteria for selection. A systematic review will include selection criteria for inclusion or exclusion, whereas a narrative review does not list the inclusion/exclusion criteria. This could lead to narrative reviews being seen as containing a bias.