# Doubt regarding Funnel plot in Meta Analysis using Metafor in R

II tried to do a Funnel plot of a dataset for a disease-prevention paper, view dataset here. Got the plot, but am worried it is wrong.The dataset contains the Hazard ratio(HR), Lower control limit(LCL), Upper control limit(UCL) and the Standard Errors(SE)[of Ln(HR)] values, and I used the SE values to calculate Variances(var in the dataset). Here is the code I used:

library(metafor)
age
res <- rma(yi=lnhr, vi=var, data=age)
res
funnel(res,xlab = "ln(HR)",ylab = "SE.ln(HR)")


The question I had was this: In most studies I have seen, the Ln(HR) values are negative, whereas in the dataset I was working on, almost all are positive. So for the correct funnel, should I take yi=-lnhr, or is yi=lnhr the correct method, in the res object?

P.S:(According to the Metafor repository linked here, yi is effect-size, and vi is the variance)

Update:Here are the results using the above code and dataset, taking yi=-lnhr

Random-Effects Model (k = 11; tau^2 estimator: REML)

tau^2 (estimated amount of total heterogeneity): 0.0001 (SE = 0.0002)

tau (square root of estimated tau^2 value): 0.0122

I^2 (total heterogeneity / total variability): 35.20%

H^2 (total variability / sampling variability): 1.54

Test for Heterogeneity:

Q(df = 10) = 16.8884, p-val = 0.0769**

Model Results:

estimate= -0.0379
se =0.0067

zval=-5.6850

pval<.0001

ci.lb=-0.0509

ci.ub=-0.0248 ***

And here is the funnel plot generated.

• Hmm it might be beneficial to explain what exactly your results were. It may be difficult to explain why you got what you did without knowing how you got there. Though I understand wanting to redact info that may be important to not share. Perhaps just the statistical values of each part of your meta may be helpful. Mar 4, 2022 at 10:12
• Negative lnHR are just positive lnHR in the other direction. Mar 4, 2022 at 15:07
• @mdewey how does that affect the Funnel? Mar 4, 2022 at 16:38
• @ShawnHemelstrand added the results I got Mar 4, 2022 at 16:39
• Why don't you write an answer based on what you found? That could help future visitors to the site with similar questions. It's OK to answer your own question that way. If you do, please provide some information about the purpose of funnel plots in meta-analysis.
– EdM
Mar 4, 2022 at 21:27