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Evidence Synthesis & Systematic Review

This guide will help you get started with your next systematic review, scoping review, or other review types.

Other names for a Living Systematic Review

LSR, Live Cumulative Network Meta-analysis (Related), Living Meta-analysis (Related)

*Note: Other review types can be "living" too.  Living refers to how it lives beyond the publication. 

Limitations of a Living Systematic Review

  • Very time consuming
  • Continuous work flows
  • Team members must have a long term commitment to the project
  • frequent searching and screening
  • frequent statistical analysis-can lead to inflated false-positive rate
  • May require technological tools to support screening, data extraction and critical analysis or risk of bia assessment (machine learning, citizen science)
  • No clear agreement on methods to manage data synthesis
  • Project funding may run out, may need to find creative ways to fund an ongoing LSR to "keep it alive" (Winters, Stay Alive!)
  • Publishing challenge-Deciding where to publish each update and how often, may require multiple DOIs and indexing in Medline, unless publishing to a project website

Source: Cochrane Learning Webinar (see resources)

What is a Living Systematic Review?

"We define an LSR as a systematic review which is continually updated, incorporating relevant new evidence as it becomes available." 

  • Are underpinned by continual, active monitoring of the evidence (i.e. monthly searches)
  • Immediately include any new important evidence (meaning data, studies or information) that is identified
  • Are supported by up-to-date communication about the status of the review, and any new evidence being incorporated

Reasons to conduct a Living Systematic Review:

  • High priority (or emerging) question for policy and practice
  • Important uncertainty in the existing evidence
  • Emerging evidence that is likely to impact on what we currently know

Other reasons:

  • To produce evidence that is both trustworthy and current
  • To encourage citizen science, embrace larger collaborations and encouraging open and shared data
  • To provide a comprehensive, always up-to-date review
  • To reduce workload by using experience from previous versions
  • To avoid "research waste"

Sources: Cochrane Collaboration and Cochrane Learning Webinar (see resources) and Stay Alive! (Winters et al.)

What is a Living Systematic Review? How it differs from a Traditional Systematic Review

Core methods are not different than a systematic review, but they require the "explicit, transparent and predefined decisions on":

  • How frequently new evidence is sought and screened (ex. need to screen monthly if searching monthly)

See our Systematic Review Search Service for help conducting the search!

  • When and how new evidence is incorporated into the review

Other differences:

  • Author Team: coordinated and continuous effort
  • Meta-analysis: potential statistical adjustments for frequently updating meta-analysis
  • Publication format: persistent, dynamic, online-only (Ex. repository, data repository)
  • Change: Methods and/or topic may change over time
  • Longevity: Thought as to when the review will no longer be living, may not need an LSR forever

Is your review question a complex intervention? Learn more about Reviews of Complex Interventions

Source: Cochrane Collaboration and Cochrane Learning Webinar (see resources)

Examples of a Living Systematic Review

Example of a LSR in a journal-The journal publishes regular updates to LSRs:

Cnossen Maryse C., Scholten Annemieke C., Lingsma Hester F., Synnot Anneliese, Tavender Emma, Gantner Dashiell, Lecky Fiona, Steyerberg Ewout W., and Polinder Suzanne. Journal of Neurotrauma. August 2016, ahead of print.