Rachael McCool

Research Consultant, York Health Economics Consortium (YHEC)

Author of: What is a systematic review?

Rachael McCool has a BSc (Hons) in Psychology from the University of York and works as a Research Consultant at York Health Economics Consortium (YHEC). She works mainly alongside the information services and systematic review team at YHEC, where she conducts a range of literature reviews from rapid scoping reviews to systematic reviews. Rachael has worked on various clinical, cost-effectiveness and burden of illness reviews requiring both qualitative and quantitative analyses, reviews to inform regulatory submissions and economic models, as well as more complex reviews involving indirect and mixed treatment comparisons.

Summary: What is a systematic review?

  • Systematic reviews have increasingly become the ‘gold standard’ in reviewing. They aim to adopt a scientific approach to identifying and consolidating all the available evidence pertaining to a specific research question and to minimise bias.
  • Systematic reviews should be carried out according to a predefined protocol that sets out the scope of the systematic review and details of the methodology to be used throughout the review. Key components of a systematic review include:
    • Systematic and extensive searches to identify all the relevant published and unpublished literature
    • Study selection according to predefined eligibility criteria
    • Assessment of the risk of bias for included studies
    • Presentation of the findings in an independent and impartial manner
    • Discussion of the limitations of the evidence and of the review.
  • Systematic reviews can evaluate a range of evidence; qualitative, quantitative or both. Appropriate methods of synthesis should be used for different types of evidence.
  • The systematic review process has been developed to minimise bias and ensure transparency. Methods should be adequately documented so that they can be replicated.
  • When conducted well, systematic reviews should give us the best possible estimate of any true effect. An assessment of the methodological quality of reviews should highlight the limitations of a review.