[R-meta] predicted intervals in metafor

[Viechtbauer Wolfgang (SP)]

Dear Raynaud,

Once you have the SMD values and corresponding sampling variances, the code is the same. Here is an example:

library(metafor)

### load data
dat <- get(data(dat.normand1999))

### calculate SMDs and corresponding sampling variances
dat <- escalc(measure="SMD", m1i=m1i, sd1i=sd1i, n1i=n1i, m2i=m2i, sd2i=sd2i, n2i=n2i, data=dat)
dat

### meta-analysis of SMD values using a random-effects model
res <- rma(yi, vi, data=dat)
res

### get prediction/credibility interval
predict(res)

If you have calculated the SMD values and variances yourself, you can skip the escalc() step and go straight to rma(). Adjust variables names as needed.

Best,
Wolfgang

-----Original Message-----
From: R-sig-meta-analysis [mailto:r-sig-meta-analysis-bounces at r-project.org] On Behalf Of Raynaud Armstrong
Sent: Friday, 15 December, 2017 1:37
To: r-sig-meta-analysis at r-project.org
Subject: [R-meta] predicted intervals in metafor

Hi there,
I would like to calculate predicted intervals in addition to my pooled
estimate and CIs as I have plenty of between-study variation in my
meta-analysis. I am using metafor package and my summary estimated is an
effect size (SMD) and not odds ratios. The examples I have come across
mainly focus on odds ratios and I wonder what to do for SMDs.
I would appreciate if someone could suggest what function to use.

Thank you,
Raynaud