[R-meta] Network Meta-analysis metafor
caroline.woehl at pg.hs-fulda.de
Wed Feb 14 08:45:29 CET 2018
I've only calucated network meta-analyses with the package netmeta yet.
Due to the possibility to calculate subgroup analyses, I'd like to have
a try at a network meta-analysis with metafor.
The analysis is based on 20 randomized controlled trials. They compare
physical activity or cognitive activity with usual care. One of them is
a multi-arm trial comparing physical and cognitive activity with usual
care. I could extract sample size, mean und standard deviation
(posttreatment) from each study arm. Thus, the file contains the study,
treat1, treat2, n1i, m1i, sd1i, n2i, m2i and sd2i.
Study treat1 treat2
n1i m1i sd1i n2i m2i sd2i
1 physical activity usual care 37 17,16 4,33
36 15,17 4,48
2 physical activity usual care 39
19,40 8,68 35 18,48 8,40
2 cognitive activity usual care 36
19,98 8,16 35 18,48 8,40
3 cognitive activity usual care 35 42,34 9,30 33
So far, I’ve calculated the standardized mean differences (yi) and
variances (vi) for each pairwise comparison.
nma <- escalc(measure="SMD", m1i=m1i, sd1i=sd1i, n1i=n1i, m2i=m2i,
sd2i=sd2i, n2i=n2i, data=nma)
How can I define usual care as the reference group in the next step?
Many thanks for your help.
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