What if I’m missing a standard deviation and only another measure of dispersion is reported?
Data extraction tips for meta-analysis
Here's a tip...
You can derive estimates of standard deviations from other reported summary data, but be aware of the assumptions underlying your estimates.
To find out more, download the pdf
Dr Kathy Taylor teaches data extraction in Meta-analysis. This is a short course that is also available as part of our MSc in Evidence-Based Health Care, MSc in EBHC Medical Statistics, and MSc in EBHC Systematic Reviews.
Follow updates on this blog and related news, and to find out about other examples of statistics being made more broadly accessible on Twitter @dataextips