Systematic Reviews: Overview

If your interactive element does not display, click the <> Embed button and close the window.

The elements of a Systematic Review

What are the different elements of a systematic review

What is it?

A systematic review attempts to identify, appraise and synthesize all the empirical evidence that meets pre-specified eligibility criteria to answer a given research question. Researchers conducting systematic reviews use explicit and reproducible methods aimed at minimizing bias in the review process, in order to produce more reliable findings that can be used to inform decision making.

Reasons for choosing

To address a clearly focused review question by finding the best available, relevant research studies and synthesizing the results.

Question

Focused on a single topic.

Sources / Search

A peer review protocol or plan is included. Clear objectives are identified. Comprehensive sources and explicit and reproducible search strategy.

Eligibility criteria

Eligibility criteria is clearly defined at the outset i.e. before the review is conducted.

Selection

Criterion-based selection that is uniformly applied, clear and explicit.

Appraisal

Rigorous critical appraisal, and evaluation of study quality.

Synthesis

Clear summaries of studies based on high quality evidence.

Inferences

Evidence based.

A meta analysis is a statistical process for amalgamating the data from different primary studies that have investigated the same issue, using suitably homogenous data 

Note that while most meta-analyses arise from a systematic review of the literature, it possible to perform a meta-analysis without doing a systemic review.

Watch the following by Dr Saravana Kumar (Senior Lecturer in Physiotherapy, UniSA) to learn more.

Type

Overview

Narrative (literature) review

Synthesizes the findings of literature retrieved from searches of computerised databases, hand searches, and authoritative texts.

Critical review

Shows that the literature has been extensively researched and critically evaluated. Goes beyond the narrative review as it contains a degree of analysis and conceptual innovation of the literature.

Scoping review

Rapid gathering of literature in a given policy or clinical area where the aims are to accumulate as much evidence as possible and map the results and provide an overview of the type, extent and quantity of research available on a given topic.

Rapid review

Uses systematic review methods to search and critically appraise the literature to assess what is already known about a particular policy or issue. How complete the searches are depends on time factors.

Systematic review

Attempts to identify, appraise and synthesize all the empirical evidence that meets pre-specified eligibility criteria to answer a given research question. Researchers conducting systematic reviews use explicit and reproducible methods aimed at minimizing bias in the review process, in order to produce more reliable findings that can be used to inform decision making.

Umbrella review

Focuses on a broad condition or problem and compiles evidence from other reviews into one document which highlights competing interventions. Does not include primary studies.

Adapted from: 'A typology of reviews' (pp.94-5).

Not sure if this is the review type for you?

Please visit library's guides for other review types

The systematic review in context:

Review types [Image source: HLWIKI International, http://hlwiki.slais.ubc.ca/index.php/File:Evidence-review-types.jpg, copied under: CC BY-NC-SA 2.5 CA, https://creativecommons.org/licenses/by-nc-sa/2.5/ca/]

Source: HLWIKI International, copied under Creative Commons (CC BY-NC-SA 2.5 CA)

Loading ...

Guidelines and standards

Using a standard or guidelines will help you conduct your systematic review. 

Cochrane Library logo [Image source: Cochrane Library, http://www.cochranelibrary.com/] Campbell Collaboration logo [Copied from: https://www.campbellcollaboration.org/] Finding what works in health care [Image source: The National Academies Press, https://www.nap.edu/catalog/13059/finding-what-works-in-health-care-standards-for-systematic-reviews]

Cochrane Library logo [Image source: Cochrane Library, http://www.cochranelibrary.com/]

“The process of preparing and publishing a Cochrane Review is different from that for other journals. Reviews are typically registered at conception and there is a closer working relationship between Cochrane and the review authors. In addition, Cochrane Reviews follow a highly structured format so that they can be published within the Cochrane Database of Systematic Reviews, and their preparation follows a structured process.”

-Cochrane Handbook, Part 1, Chapter 2.1.

Loading ...

Image attributions

The process

Step 1 - A clear and focused question.

  • This may require preliminary searching (scoping) to see what evidence is already available and whether a Systematic Reviews has been done before.

Step 2 - Develop a protocol.

  • This is your plan (or recipe) for your review.
    • Search strategy and databases
    • Eligibility criteria
    • Screening process
    • Critical appraisal process
    • Data analysis / synthesis process
  • Register your protocol with Prospero or publish it in a relevant journal.

 

Then, per your protocol:

Step 3 - Conduct systematic searches.

Step 4 - Screen results for relevant studies that meet your eligibility criteria.

Step 5 - Critically appraise the quality of the included studies.

Step 6 - Extract relevant data from the included studies.

Step 7 - Data synthesis.

Step 8 - Summarise and interpret the evidence to answer your question.

Further resources

**Submit broken link on this page**