[R-meta] Fwd: predicted intervals in metafor
Viechtbauer, Wolfgang (SP)
wolfg@ng@viechtb@uer @ending from m@@@trichtuniver@ity@nl
Mon Jun 25 10:14:34 CEST 2018
Not sure if you ever received an answer to this.
In essence, the results indicate no evidence for residual heterogeneity in the true effects. I suspect that there is little (or any) evidence for heterogeneity in these data in the first place (i.e., without including moderators in the model, the Q-test is probably not significant to begin with and I^2 might be zero or close to it).
But I see: "vi=se_cohen". Argument 'vi' is for the *sampling variances*. However, 'se_cohen' suggests that you are passing the *stanard errors* to the function. This would be incorrect. Either use "vi=se_cohen^2" or "sei=se_cohen".
From: Raynaud Armstrong [mailto:raynaud.armstrong using gmail.com]
Sent: Friday, 08 June, 2018 19:24
To: Michael Dewey
Cc: Viechtbauer, Wolfgang (SP); r-sig-meta-analysis using r-project.org
Subject: Re: [R-meta] Fwd: predicted intervals in metafor
Sorry, I had forgotten to reply to the subscription email. I believe I am now registered.
My apologies once again.
On Fri, Jun 8, 2018 at 1:12 PM, Michael Dewey <lists using dewey.myzen.co.uk> wrote:
Ray, please keep the list in the loop and please register so we do not have to approve each post.
On 08/06/2018 18:03, Raynaud Armstrong wrote:
---------- Forwarded message ----------
From: Raynaud Armstrong <raynaud.armstrong using gmail.com>
Date: Fri, Jun 8, 2018 at 1:02 PM
Subject: Re: [R-meta] predicted intervals in metafor
To: Michael Dewey <lists using dewey.myzen.co.uk>
Thanks Michael. *I got the following output for my meta-regression. My
heterogeneity statistics are all 0 - what does this mean?*
metareg <- rma (yi=cohen, vi=se_cohen, mods = ~ mean_age + year +
In rma(yi = cohen, vi = se_cohen, mods = ~mean_age + year + country, :
Studies with NAs omitted from model fitting.
Mixed-Effects Model (k = 7; tau^2 estimator: REML)
tau^2 (estimated amount of residual heterogeneity): 0 (SE = 0.1825)
tau (square root of estimated tau^2 value): 0
I^2 (residual heterogeneity / unaccounted variability): 0.00%
H^2 (unaccounted variability / sampling variability): 1.00
R^2 (amount of heterogeneity accounted for): NA%
Test for Residual Heterogeneity:
QE(df = 3) = 0.3265, p-val = 0.9550
Test of Moderators (coefficient(s) 2:4):
QM(df = 3) = 1.6838, p-val = 0.6406
estimate se zval pval ci.lb ci.ub
intrcpt 39.8696 65.5910 0.6079 0.5433 -88.6863 168.4255
mean_age 0.0456 0.0373 1.2223 0.2216 -0.0275 0.1187
year -0.0203 0.0332 -0.6109 0.5413 -0.0852 0.0447
countryUSA -0.1974 0.3959 -0.4987 0.6180 -0.9733 0.5785
Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
Please let me know. Thanks.
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