Systematic Review

Systematic Review

What is Systematic review?

A systematic review is an overview of primary studies that uses explicit and reproducible methods. A systematic review may include a meta-analysis – a mathematical synthesis of the results of two or more primary studies that addressed the same hypothesis in the same way (Greenhalgh 1997). In addition to or instead of a meta-analysis a systematic review may include a narrative review – the process of synthesising primary studies and exploring heterogeneity descriptively rather than statistically (Petticrew 2003). Increasingly systematic reviews are considering qualitative as well as quantitative evidence, (see for example Dixon-Woods et al, 2005; Dixon-Woods et al 2006).

Why might you might want to include systematic methods

  • explicit methods limit inclusion bias  – extensive searching limits publication bias and results in more trustworthy conclusions
  • succinctly summarises large amounts of information for audiences such as clinicians, policy makers which may reduce time to implementation
  • highlights research gaps – maps what is known and what is unknown
  • formal comparison of studies

What expertise can a systematic review advisor offer?

  • refine your research question
  • advice on approaches to searching
  • advice on managing the process of systematic reviewing

What to think about before a meeting with a systematic review advisor

  • a scoping review of studies relating to your research question

RDS NE Systematic Review Team Lead: Dawn Craig

Useful Resources

Dixon-Woods M, D Cavers, S Agarwal et al.  Conducting a critical interpretive synthesis of the literature on access to healthcare by vulnerable groups.  BMC Med Res Methodol.  2006; 6:35-

Dixon-Woods M, S Agarwal, D Jones et al.  Synthesising qualitative and quantitative evidence: a review of possible methods.  J Health Serv Res Policy.  2005; 10:1:45-53

Greenhalgh T.  How to read a paper: papers that summarise other papers (systematic reviews and meta-analyses). BMJ. 1997; 315: 672-

Petticrew M.  Why certain systematic reviews reach uncertain conclusions.  British Medical Journal.  2003; 326:7392:756-758