Systematic reviews

A systematic review is a summary of all relevant research on a clearly defined question. The search process follows strict, predefined criteria.

Systematic reviews are used in many research areas and can have different purposes. One purpose may be to map the literature within a field. Another may be to calculate statistical measures of treatment effects. The library can support you with:

• Introduction to method
• Formulating and structuring research questions
• Creating search queries
• Conducting information retrieval
• Screening tools
• Reference management software
• Documentation

Characteristics of a Systematic Review

A systematic review is time- and resource-intensive. The research questions are highly specific and clearly defined. Information retrieval is based on carefully chosen criteria that reflect the purpose of the review. The aim is to gather material that is both comprehensive and relevant. You need to:

• Follow a strict method.
• Use a wide range of sources and tools.
• Evaluate and summarise the material you retrieve.

There are different types of reviews, such as rapid reviews, scoping reviews, and systematic reviews. They vary in scope and level of detail.

Process for Systematic Reviews

Systematic reviews are usually conducted step by step. Here is an overview of the process.

Formulate and structure the research question

• Define your research question clearly. To structure it, you can use models such as PICO, PEO, SPICE or SPIDER.
• Also decide on inclusion and exclusion criteria, such as publication type, publication year, or study design/method.
  

Build your search query

• Identify search terms from your research question.
• Find additional terms using, for example, gold standard articles, expert opinions, concept analyses, subject heading lists, reference lists or citations.
  

Conduct the literature search

• Run a systematic search in the databases you selected in advance.
• If needed, complement this with other methods, such as manual searches in selected journals.

Remove duplicates

• Eliminate duplicate records using a screening tool or a reference management program.

Appraise the material

• Assess the studies you have found based on inclusion and exclusion criteria, relevance and quality.
• Start with abstracts. For studies that meet the criteria, continue with the full texts.
• Then compile and analyse the relevant data from the remaining publications.
• In some fields, you may also need to grade the evidence to judge the reliability of the results. One example is the international system GRADE.

Document the process

• Document the whole review process clearly. It should be transparent, verifiable and reproducible so others can follow and repeat it.

Useful links

• Instructional videos from SBU
  Short films with information about systematic reviews from SBU – the Swedish Agency for Health Technology Assessment and Assessment of Social Services. Available in Swedish.
  
• Systematic reviews – for researchers
  Learn more on the Karolinska Institutet University Library website.
  
• Introduction to common review types
  Detailed information from Temple University Libraries on different types of systematic reviews.
  
• Support for systematic reviews
  Guidance and resources from the SLU Library.
  
• PRESS 2015 checklist for search strategies
  A checklist available on the Karolinska Institutet University Library website.
  
• The Systematic Review Toolbox
  Tools for conducting systematic reviews, available on the SR Toolbox website.