Preparing for a Comprehensive Literature Review

There are many different types of reviews, each lending themselves to a specific purpose.  For example, systematic reviews are intended to identify, critically appraise and synthesize the results of studies that address a specific research question while scoping reviews are intended to describe/map the research conducted in a more general area.  Selection of studies for a systematic review is normally limited to the gold standard study methodology for the type of question being addressed while an integrative review would include relevant studies of any methodology.

The following articles discuss the various types of the reviews and outlines the characteristics of each:

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. doi:10.1111/j.1471-1842.2009.00848.x

Gough, D., Thomas, J., & Oliver, S. (2012). Clarifying differences between review designs and methods. Systematic Reviews, 1, 28-4053-1-28. doi:10.1186/2046-4053-1-28

Munn, Z., Stern, C., Aromataris, E. et al. What kind of systematic review should I conduct? A proposed typology and guidance for systematic reviewers in the medical and health sciences. BMC Med Res Methodol 18, 5 (2018). doi.org/10.1186/s12874-017-0468-4

Sutton, A., Clowes, M., Preston, L., & Booth, A. (2019). Meeting the review family: exploring review types and associated information retrieval requirements. Health Information & Libraries Journal, 36(3), 202-222. doi:10.1111/hir.12276

Temple University provides useful descriptions of some of the types of reviews listed in the above article at http://guides.temple.edu/c.php?g=78618&p=3879604

The follow article provides some additional discussion to aid in selecting the appropriate review type:

Greenhalgh, T., Thorne, S. & Malterun, K. (2018).  Time to challenge the spurious hierarchy of systematic over narrative reviews?  European Journal of Clinical Investigation, 48(6), e12931.  doi:10.1111/eci.12931

The following need to be taken into consideration when deciding upon a review type:

• What is the nature of your question?
  • Is the question best answered by quantitative studies (systematic review; meta-analysis) or qualitative studies (meta-synthesis) or both (integrative review)?
  • Are you more interested in describing the nature and extent of the research in a particular area rather than answering a specific question (scoping review)?
• Is the review to be undertaken by a team or will you be conducting this on your own?
  • To minimize bias, a true systematic review is supposed to be undertaken by a review team, with screening and appraisal conducted independently by at least two team members with a third member available to settle disagreements.
  • A meta-analysis requires the pooling and statistical analysis of study results.  If you do not have the expertise in statistical analysis, will you be on a team that includes a statistician?
  • Reviews labeled 'systematic reviews' with single authors do appear in the form of Masters theses, PhD dissertations and capping projects, but a review labeled as a systematic review authored by a single person is not likely to be published.  
    • It is still possible to have a non-systematic review (e.g. critical reviews, narrative reviews)  published in a reputable journal.  Might it be better to avoid labeling your review as a systematic review if it does not meet the criteria of a true systematic review? 
• How much literature do you expect to retrieve? 
  • Will you have the time to screen your search results and summarize included studies in the time frame allotted if you undertake one of the more rigorous types of reviews?
• What are the expectations of your supervisor?
  • Are they expecting you to do a specific type of review?
  • It is a good idea to discuss with your supervisor exactly what they expect of the review, e.g. do they expect you to use the PRISMA guidelines, will they accept a 'mini' version of one of the more rigorous reviews if time and resources are limited?