Systematic Reviews

A systematic review attempts to collate all empirical evidence that fits pre-specified eligibility criteria in order to answer a specific research question.  It  uses explicit, systematic methods that are selected with a view to minimizing bias, thus providing more reliable findings from which conclusions can be drawn and decisions made (Antman 1992, Oxman 1993). The key characteristics of a systematic review are:

• a clearly stated set of objectives with pre-defined eligibility criteria for studies;
• an explicit, reproducible methodology;
• a systematic search that attempts to identify all studies that would meet the eligibility criteria;
• an assessment of the validity of the findings of the included studies, for example through the assessment of risk of bias; and
• a systematic presentation, and synthesis, of the characteristics and findings of the included studies. (Source: Cochrane)

"Statistical methods (meta-analysis) may or may not be used to analyze and summarize the results of the included studies. Meta-analysis refers to the use of statistical techniques in a systematic review to integrate the results of included studies."

Systematic review search: utilizing the Article Type filter will limit to systematic reviews.​ Note: other types of reviews (e.g., literature review) may also be retrieved.

Selecting the filter:

• Perform a search – the example below is for fibromyalgia
• Check the box next to Systematic Review
• The search results page will automatically reload to display the filtered results

Protocol search: same filtered search as above plus AND protocol:

Note: this search technique is inexact and will possibly retrieve systematic reviews including studies employing other types of protocols, as indicated by viewing the abstract for result #3 above (not shown here).

Once it has been decided that a systematic review will be conducted, this may be the time to select a journal which may be the most relevant. Journal editors will judge a systematic review based upon various parameters, including how it may add value to the scientific knowledge base, change clinical practice, fit within the journals’ mission and whether it complies with a particular standard such as PRISMA. Familiarity with the publication’s “instructions to authors” may save time in this regard. 

A team discussion on whether the systematic review will be updated in the future is helpful. Currently, there seems to be no consensus on when and how this process should be accomplished. Some brief points to consider are:

• Who will lead the update in the future and how will its necessity be determined?
• Which bibliographic management system will the references from the first systematic review be held?
• How will the search strategy be updated?

Select references:

Producing a protocol as the “plan” for the systematic review is required, as it enhances communication between team members, reduces potential for bias, and provides the research community with an informed view of the eventual systematic review process, if published. Guidance for formatting a protocol can be found below.

Why Register a Systematic Review Protocol:

PRISMA-P:

PROSPERO:

Cochrane Protocols: format may be standardized by the individual group. Required to be published in the Cochrane Library before starting the systematic review.