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
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