I am trying to run a meta-analysis calculating the mean effect size of a manual therapy treatment on pressure pain threshold pre-post treatment (i.e. within-group change), so there is no comparison to sham/control. I will be using mean change from baseline (continuous) and I have SDs/CIs of the change. There are 10 studies, and most studies have multiple testing sites (e.g. at the lower back and at the calf) so each site needs to be included separately. I’ll need to run it under a random-effects model. Can I do this? And if so, how do I go about it?
Most information out there about meta-analysis is very focused on inter-group comparisons so I've been unable to find a clear answer.
If I can, I’m uncertain of which programs would allow me to do it. Presumably I could use R since there are so many packages available – any suggestions on packages that might suit? Based on a trial of the program Comprehensive Meta-Analysis it seems to do what I’m looking for, but is rather expensive ($500 for 1 year license, unless I purchase with my own money as a student). I have also looked into RevMan, but from what I can gather it only supports inter-group comparisons, since Cochrane reviews are typically looking at mean differences comparing a treatment against control/placebo/gold standard. Please correct me if I am wrong here. Are there any other good programs that are cheap/free that would do what I want?
Any help is appreciated, thanks.
Best Answer
There is no need to spend money. There are several options available in R of which both metafor and meta are actively maintained and developed. There are also Stata solutions if you have access to it.
The meta analysis model just needs an effect size and its standard error from each study. It neither knows nor cares whether this comes from a comparative study or a non-comparative study. I would start by analysing each site separately although the canonical analysis would use all in asingle model.
Just a final comment, R is only free if you do not charge for the time you spend learning it.