Once you have decided which articles to include in your review, you need to extract relevant data from those studies. This should be done in a structured and systematic way and is usually presented in tables in the final review report.
Tips:
- Extract only the data that is relevant to your research question
- Create a table or data collection form so that you can summarise the data consistently for each study
- Convert all the data to the same units of measurement, where possible
- Make sure your table headings can be easily interpreted by others
- Make sure any abbreviations or acronyms used in the table are explained in footnotes
- Pilot your data extraction method before you start – especially if more than one person is extracting the data.
Useful Tools
You can extract your data into a simple table, but if you want a more detailed approach there are a number of analysis tools that can help:
- NVivo (CSU supported and great for qualitative data analysis)
- Dovetail - alternative to NVivo, without the steep learning curve. Use it for qualitative data analysis plus it transcribes audio. There is a free version available. Get started with Dovetail for beginners.
- PSPP (Open source software)
- JASP (Open source software)
- GRADEpro software has been developed by the GRADE working group to support the creation of Summary of Findings Tables for Cochrane Reviews and Evidence Profiles. More information about the GRADE approach to assessing the quality of evidence can be found in the Cochrane Handbook for Systematic Reviews of Interventions. Watch how to use GRADEpro or view the handbook for more information.
- Elamin, M. B., Flynn, D. N., Bassler, D., Briel, M., Alonso-Coello, P., Karanicolas, P. J., Guyatt, G. H., Malaga, G., Furukawa, T. A., & Kunz, R. (2009). Choice of data extraction tools for systematic reviews depends on resources and review complexity. Journal of Clinical Epidemiology, 62(5), 506-510. https://doi.org/10.1016/j.jclinepi.2008.10.016
Resources