[R-meta] Show study labels

[Viechtbauer, Wolfgang (SP)]

Dear Ray,

Please give your post an appropriate subject (I've added one in my reply).

Also please post in plain text. The formatting can get all screwed up when posting in HTML (I've fixed that below in my reply).

Finally, a fully reproducible example would make it easier to provide help.

Based on what you show, the error should not occur. This runs without error:

vahe <- read.table(header=TRUE, text = "
studyID corr fisherz stderr
'Nicks et al., 2013' 0.05 0.05 0.1
'Fedro et al., 2013' 0.4 0.42 0.1
'Bonnes et al., 2013' 0.2 0.2 0.05
'Sylvi et al., 2014' 0.14 0.14 0.06
'Trente et al., 2015' 0.23 0.23 0.09
'Martin et al., 2003' 0.17 0.2 0.05
'Margolin-Angel et al., 2002' 0.26 0.3 0.1
'Livingstone et al., 2008' 0.025 0.03 0.05
'Brack et al., 2011' 0.026 0.03 0.09
'Robinson-Papp et al., 2008' 0.202 0.2 0.06
'Bicker et al., 2015' 0.0037 0.003 0.09
'Lister et al., 2007' 0.049 0.05 0.07
'Melody et al., 2011' 0.24 0.2 0.11
'Wheels et al., 2008' 0.2 0.2 0.13
'Thames et al., 2011' -0.22 -0.2 0.09
'Ringer et al., 2000' -0.16 -0.16 0.12
'Mellow et al., 2013' -0.52 -0.6 0.1")

metavahe <- rma(yi=fisherz, sei=stderr, data=vahe)

forest(metavahe, showweights=TRUE, xlab='Pooled Estimate of Fisher Z Scores', order="obs", slab=paste(vahe$studyID))

My guess is that 'vahe' includes one or more additional rows that you are not showing. But you could also do:

metavahe <- rma(yi=fisherz, sei=stderr, data=vahe, slab=paste(vahe$studyID))

forest(metavahe, showweights=TRUE, xlab='Pooled Estimate of Fisher Z Scores', order="obs")

Then you will also get the study labels in the forest plot and extra rows won't cause any problems.

Best,
Wolfgang

-----Original Message-----
From: Raynaud Armstrong [mailto:raynaud.armstrong using gmail.com] 
Sent: Tuesday, 14 August, 2018 21:47
To: r-sig-meta-analysis using r-project.org; Viechtbauer, Wolfgang (SP)
Subject: Re: Show study labels

Hi everyone! 
Here's my hypothetical data which I am working on for a meta-analysis assignment. I transformed correlation coefficients to Fisher's Z  manually. Then used metafor in R to get my pooled estimate of Z. I would like my forest plot to display the study references fully instead of the default 'Study 1,Study 12' format. Could you please validate my script format and help with the forest plot as I keep getting the error message shown below the following data? Thanks in advance! 

studyID corr fisherz stderr
Nicks et al., 2013 0.05 0.05 0.1
Fedro et al., 2013 0.4 0.42 0.1
Bonnes et al., 2013 0.2 0.2 0.05
Sylvi et al., 2014 0.14 0.14 0.06
Trente et al., 2015 0.23 0.23 0.09
Martin et al., 2003 0.17 0.2 0.05
Margolin-Angel et al., 2002 0.26 0.3 0.1
Livingstone et al., 2008 0.025 0.03 0.05
Brack et al., 2011 0.026 0.03 0.09
Robinson-Papp et al., 2008 0.202 0.2 0.06
Bicker et al., 2015 0.0037 0.003 0.09
Lister et al., 2007 0.049 0.05 0.07
Melody et al., 2011 0.24 0.2 0.11
Wheels et al., 2008 0.2 0.2 0.13
Thames et al., 2011 -0.22 -0.2 0.09
Ringer et al., 2000 -0.16 -0.16 0.12
Mellow et al., 2013 -0.52 -0.6 0.1

Output of my random effects model:
 metavahe <-rma(yi=fisherz, sei=stderr, data=vahe)
> metavahe

Random-Effects Model (k = 17; tau^2 estimator: REML)

tau^2 (estimated amount of total heterogeneity): 0.0429 (SE = 0.0178)
tau (square root of estimated tau^2 value):      0.2071
I^2 (total heterogeneity / total variability):   88.27%
H^2 (total variability / sampling variability):  8.52

Test for Heterogeneity: 
Q(df = 16) = 98.2105, p-val < .0001

Model Results:

estimate      se    zval    pval    ci.lb   ci.ub   
  0.0787  0.0545  1.4431  0.1490  -0.0282  0.1855   

---
Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 

FOREST PLOT SCRIPT:
forest(metavahe, showweights=TRUE, xlab='Pooled Estimate of Fisher Z Scores', order="obs")
This gives me a plot with Study 1, Study 2 format.
If I try the following, then it gives me an error: (vahe is the actual .csv file where I have my data)

> forest(metavahe, showweights=TRUE, xlab='Pooled Estimate of Fisher Z Scores', order="obs", slab=paste(vahe$studyID))
Error in forest.rma(metavahe, showweights = TRUE, xlab = "Pooled Estimate of Fisher Z Scores",  : 
  Number of outcomes does not correspond to the length of the 'slab' argument.

I would like the full study references to be written out - What shall I do?
Please let me know soon.
Thanks,
Ray