Skip to Main Content

How to get started with systematic literature searching

What is a systematic review?

A systematic review is a type of research that aims to answer a clearly defined question by gathering, evaluating, and synthesising all relevant studies on that topic. It follows a structured and transparent process designed to reduce bias and provide reliable evidence for research, policy, or practice. Systematic reviews typically involve:

  • A focused research question
  • A comprehensive and reproducible search
  • Clear criteria for including or excluding studies
  • Critical appraisal of study quality
  • A structured summary or synthesis of findings

Systematic reviews are complex projects that require careful planning, time, and teamwork. You should not attempt one alone - they usually involve input from researchers, subject experts, librarians, and sometimes statisticians or methodologists. They also require familiarity with specialised tools for searching, screening, quality assessment, and data extraction.

UWS Library Services staff and resources are available to support you whatever type of literature review you are conducting. If you’re unsure whether a systematic review is right for your project, speak to one of your Research Support Librarians - who can help you think through your question and what support you’ll need.

Before you begin: ask yourself

Not every literature review needs to be a systematic review. These questions will help you decide if it’s the right approach for your project - or whether a more flexible method (like a structured literature review) is better suited.

You don’t need to conduct a full systematic review for your work to be meaningful, rigorous, or valuable.

If a structured, well-documented literature review is the right fit for your topic, that’s completely valid especially at undergraduate or master's level.

Don’t feel pressured to label your work as a systematic review if it doesn’t meet the formal criteria. Being honest about your method shows academic maturity, not a lack of skill.

Checklist: are you ready to conduct a systematic review?

Question

Yes / No

Is your research question clearly focused and suitable for systematic investigation?

☐ / ☐

Do you have the time and capacity to conduct a comprehensive search across multiple sources?

☐ / ☐

Will your review involve setting clear inclusion and exclusion criteria?

☐ / ☐

Can you commit to documenting every step of your search process in detail?

☐ / ☐

Are you able to critically appraise the quality of the studies you find?

☐ / ☐

Do you need input or collaboration from others with subject or methods expertise?

☐ / ☐

Have you reviewed existing protocols or registered reviews to avoid duplication?

☐ / ☐

Will you use a recognised reporting guideline (e.g. PRISMA)?

☐ / ☐

 

💡 If you answered “no” to more than one or two of these, you may benefit from rethinking the review method - or seeking advice from your  Research Support Librarian and supervisor.

What kind of systematic review should I conduct?

Most of us are familiar with the terms systematic review and literature review. Both review types synthesise evidence and provide summary information. So, what are the differences? And which approach is best? 

More than 30 types of systematic review have been described, though the number isn’t fixed. If you're new to systematic reviews, the terminology can be confusing. Students are often asked to conduct a "systematic review" when what's really expected is a literature review carried out in a systematic way. Full systematic reviews are methodologically rigorous and often unsuitable for individual researchers working alone or to short deadlines.

This table outlines common review types, but it isn’t exhaustive. Definitions and boundaries can vary, and terms are sometimes used interchangeably.

Label Description Search Appraisal Synthesis Analysis
Critical review Aims to demonstrate writer has extensively researched literature and critically evaluated its quality. Goes beyond mere description to include degree of analysis and conceptual innovation. Typically results in hypothesis or mode Seeks to identify most significant items in the field No formal quality assessment. Attempts to evaluate according to contribution Typically narrative, perhaps conceptual or chronological Significant component: seeks to identify conceptual contribution to embody existing or derive new theory
Literature review Generic term: published materials that provide examination of recent or current literature. Can cover wide range of subjects at various levels of completeness and comprehensiveness. May include research findings May or may not include comprehensive searching May or may not include quality assessment Typically narrative Analysis may be chronological, conceptual, thematic, etc.
Mapping review/ systematic map Map out and categorise existing literature from which to commission further reviews and/or primary research by identifying gaps in research literature Completeness of searching determined by time/scope constraints No formal quality assessment May be graphical and tabular Characterizes quantity and quality of literature, perhaps by study design and other key features. May identify need for primary or secondary research
Meta-analysis Technique that statistically combines the results of quantitative studies to provide a more precise effect of the results Aims for exhaustive, comprehensive searching. May use funnel plot to assess completeness Quality assessment may determine inclusion/ exclusion and/or sensitivity analyses Graphical and tabular with narrative commentary Numerical analysis of measures of effect assuming absence of heterogeneity
Mixed studies review/mixed methods review Refers to any combination of methods where one significant component is a literature review (usually systematic). Within a review context it refers to a combination of review approaches for example combining quantitative with qualitative research or outcome with process studies Requires either very sensitive search to retrieve all studies or separately conceived quantitative and qualitative strategies Requires either a generic appraisal instrument or separate appraisal processes with corresponding checklists Typically both components will be presented as narrative and in tables. May also employ graphical means of integrating quantitative and qualitative studies Analysis may characterise both literatures and look for correlations between characteristics or use gap analysis to identify aspects absent in one literature but missing in the other
Overview Generic term: summary of the [medical] literature that attempts to survey the literature and describe its characteristics May or may not include comprehensive searching (depends whether systematic overview or not) May or may not include quality assessment (depends whether systematic overview or not) Synthesis depends on whether systematic or not. Typically narrative but may include tabular features Analysis may be chronological, conceptual, thematic, etc.
Qualitative systematic review/qualitative evidence synthesis Method for integrating or comparing the findings from qualitative studies. It looks for ‘themes’ or ‘constructs’ that lie in or across individual qualitative studies May employ selective or purposive sampling Quality assessment typically used to mediate messages not for inclusion/exclusion Qualitative, narrative synthesis Thematic analysis, may include conceptual models
Rapid review Assessment of what is already known about a policy or practice issue, by using systematic review methods to search and critically appraise existing research Completeness of searching determined by time constraints Time-limited formal quality assessment Typically narrative and tabular Quantities of literature and overall quality/direction of effect of literature
Scoping review Preliminary assessment of potential size and scope of available research literature. Aims to identify nature and extent of research evidence (usually including ongoing research) Completeness of searching determined by time/scope constraints. May include research in progress No formal quality assessment Typically tabular with some narrative commentary Characterizes quantity and quality of literature, perhaps by study design and other key features. Attempts to specify a viable review
State-of-the-art review Tend to address more current matters in contrast to other combined retrospective and current approaches. May offer new perspectives Aims for comprehensive searching of current literature No formal quality assessment Typically narrative, may have tabular accompaniment Current state of knowledge and priorities for future investigation and research
Systematic review Seeks to systematically search for, appraise and synthesis research evidence, often adhering to guidelines on the conduct of a review Aims for exhaustive, comprehensive searching Quality assessment may determine inclusion/exclusion Typically narrative with tabular accompaniment What is known; recommendations for practice. What remains unknown; uncertainty around findings, recommendations for future research
Systematic search and review Combines strengths of critical review with a comprehensive search process. Typically addresses broad questions to produce ‘best evidence synthesis’ Aims for exhaustive, comprehensive searching May or may not include quality assessment Minimal narrative, tabular summary of studies What is known; recommendations for practice. Limitations
Systematized review Attempt to include elements of systematic review process while stopping short of systematic review. Typically conducted as postgraduate student assignment May or may not include comprehensive searching May or may not include quality assessment Typically narrative with tabular accompaniment What is known; uncertainty around findings; limitations of methodology
Umbrella review Specifically refers to review compiling evidence from multiple reviews into one accessible and usable document. Focuses on broad condition or problem for which there are competing interventions and highlights reviews that address these interventions and their results Identification of component reviews, but no search for primary studies Quality assessment of studies within component reviews and/or of reviews themselves Graphical and tabular with narrative commentary What is known; recommendations for practice. What remains unknown; recommendations for future research

 

The table is based on the following work:

Grant, M.J., and Booth, A. (2009), 'A typology of reviews: an analysis of 14 review types and associated methodologies', https://doi.org/10.1111/j.1471-1842.2009.00848.x (Accessed: 23 January 2025).

Munn, Z., Stern, C., Aromataris, E., Lockwood, C., and Jordan, Z. (2018), 'What kind of systematic review should I conduct? A proposed typology and guidance for systematic reviewers in the medical and health sciences', BMC Medical Research Methodology, 18, article number 5. Available at: https://10.1186/s12874-017-0468-4 (Accessed: 22 January 2025).

Sutton, A., Clowes, M., Preston, L., and Booth, A. (2019), 'Meeting the review family: exploring review types and associated information retrieval requirements', Health Information & Libraries Journal, 36(3), pp. 202-222. Available at: https://doi.org/10.1111/hir.12276 (Accessed: 22 January 2025).

Understanding systematic reviews: types, methods, and setup

Systematic reviews address predetermined research inquiries employing clear, replicable methodologies to locate, evaluate, and amalgamate findings from primary research investigations. The essential features of a systematic review include: (a) clearly defined objectives with a methodological approach that is transparent and replicable; (b) a methodical search strategy aimed at identifying all relevant studies meeting the predefined criteria; (c) an evaluation of the reliability of the results from the selected studies, such as assessing bias risk and confidence in cumulative estimates; and (d) a systematic and organised presentation and analysis of the identified studies' characteristics and outcomes.

Systematic review methodologies

Systematic reviews can use different methodologies depending on the type of evidence being analysed. Common approaches include:

  • Quantitative (e.g. meta-analysis) – combines numerical data from multiple studies
  • Qualitative (e.g. thematic synthesis) – identifies patterns or themes across qualitative research
  • Mixed methods – integrates both qualitative and quantitative evidence
  • Scoping and mapping – explore the extent, range, and nature of research on a topic

Each method has its own tools, strengths, and suitability depending on your research question.

To explore various review methodologies and determine the most suitable approach for your topic, we recommend consulting the following resources:

Gough, D., Thomas, J. and Oliver, S. (2017) An introduction to systematic reviews. 2nd ed. London: Sage.

Higgins, J. P. T., Thomas, J., Chandler, J., Cumpston, M., Li, T., Page, M. J. and Welch, V. A. (2024) Cochrane Handbook for Systematic Reviews of Interventions version 6.5 (updated August 2024). Hoboken, NJ: John Wiley & Sons. Available at: https://www.training.cochrane.org/handbook (Accessed 25 June 2025)

Siddaway A.P., Wood, A.A., and Hedges, L.V. (2018) 'How to Do a Systematic Review: A Best Practice Guide for Conducting and Reporting Narrative Reviews, Meta-Analyses, and Meta-Syntheses', Annual Review of Psychology, 70, pp. 747-770. Available at: https://doi.org/10.1146/annurev-psych-010418-102803 (Accessed: 10 February 2024).

Pollock, A. and Berge, E. (2018) 'How to do a systematic review', International Journal of Stroke, 13(2), pp. 138-156. Available at: https://doi.org/10.1177/1747493017743796#bibr5-1747493017743796 (Accessed: 14 February 2024).

Covidence (2024) How to write the methods section of a systematic review. Available at: https://www.covidence.org/blog/how-to-write-the-methods-section-of-a-systematic-review/ (Accessed: 25 June 2025.