Systematic Reviews: Hints and tips Ellen Backhouse www.ccace.ed.ac.uk

www.ccace.ed.ac.uk Our systematic review Early life risk factors for stroke and subclinical cerebrovascular disease Looking at whether poorer childhood SES, lower education and lower IQ were associated with increased risk of cerebrovascular disease (white matter hyperintensities, perivascular spaces, small vessel disease etc.) or clinically evident stroke. We searched Medline, EMBASE and PsycInfo electronically and hand searched Stroke, Neurology and International Journal of Epidemiology. This is our PRISMA diagram which shows how many papers we identified, how many abstracts scanned, how many full texts were read, how many studies we included. www.ccace.ed.ac.uk Figure 1. PRISMA Flow chart of methodology and study selection Backhouse et al., Neurology 2017; 88(7): 976-984 McHutchison et al., Epidemiol, 2017; 28(4): 608-618

Hints and tips: Before you start Write a protocol What are the objectives of the review and what questions will be addressed? What databases are you going to search? What are your inclusion/exclusion criteria? What data are you going to extract? Quality assessment Register on PROSPERO www.crd.york.ac.uk/prospero/

Hints and tips: Developing a search strategy Get help from a librarian Test your search terms Do they return papers you would expect to see? Test using different databases Record the date of the search Different MeSH headlines Developing a search strategy is Different use of wild cards

Hints and tips: screening articles Be over-inclusive Note everything that might be of interest Record clear reasons for exclusion Discuss with the wider research group Don’t forget the supplementary material Take breaks!

Hints and tips: Data extraction Designing the form What information should I extract? Paper/Electronic? Test the form Get someone who hasn’t been involved to test it Consider different ways of conducting double data extraction Important identifying information Easy to identify papers on the same population

Hints and tips: data analysis A table of included studies can be useful Don’t panic if your results are heterogeneous Can use a mixture of narrative and statistical analysis Can use raw data to calculate effect sizes If doing a meta-analysis use useful software programmes such as Review Manager R Use similar reviews for reference

Hints and tips: Write up and submission Use other programs to edit the figures (e.g. add extra labels and legends etc.) Adobe photoshop/elements Inkscape (it’s free!) MS Paint MS Powerpoint Check the journals submission requirements before you do anything Are there things that can be included as supplementary documents? Check the format for figures/tables This process can take a while – be patient! Useful for producing high quality images Can be used to make minor changes

Hints and tips: general points Don’t underestimate the time required Record EVERYTHING Don’t panic if it takes longer than expected

www.ccace.ed.ac.uk Acknowledgements Systematic Review Team Caroline McHutchison Professor Joanna Wardlaw Dr Susie Shenkin Dr Vera Cvoro Cochrane Librarian Brenda Thomas www.ccace.ed.ac.uk