Closed prabpharm closed 4 years ago
Dear Prabhakar,
You can use R function metagen
to calculate the standard error of the log hazard ratio from the confidence interval:
study <- c("FCG on CLL 1996", "Leporrier 2001", "Rai 2000", "Robak 2000")
HR <- c(0.55, 0.92, 0.79, 1.18)
lower.HR <- c(0.28, 0.79, 0.59, 0.64)
upper.HR <- c(1.09, 1.08, 1.05, 2.17)
# Input must be log hazard ratios, not hazard ratios
m <- metagen(log(HR), lower = log(lower.HR), upper = log(upper.HR),
studlab = study, sm = "HR")
# Log hazard ratio
m$TE
# Standard error of log hazard ratio
m$seTE
print(metagen(m$TE, m$seTE, sm = "HR", studlab = m$studlab), digits = 2)
Concerning your second question, it is possible to conduct a network meta-analysis with only two studies (e.g., comparing A vs Placebo and B vs Placebo). However, there is no possibility to check whether the treatment comparisons are consistent as you only have indirect evidence for the comparison A vs B.
Best wishes, Guido
Thank you so much for answering! Really appreciate you taking time and helping.
Dear Guido, I am trying to run an NMA using netmeta, where effect size is hazard ratio (confidence interval) using the following code:
nma1 <- netmeta(TE = lnHR, seTE = lnSE, treat1 = treat1, treat2 = treat2, studlab = study, sm = "HR")
As you highlighted in one of the issues discussed earlier https://github.com/guido-s/netmeta/issues/4#issue-399944434, I have used log of hazard ratio (lnHR
) and its SE (lnSE
). I imputed these variables separately and added to my dataframe. My question is, does the netmeta function has any argument/other mechanism to calculate logs in a single line of code, or for calculating SE from CIs? I tried to find the solution in the package documentation but failed (maybe due to my limited understanding).My second question is not about the netmeta package, but about NMA is general, I am not sure if should ask you about this here. I am pooling only two studies (and two treatment comparisons) in this NMA. Does that make any sense, pooling just two comparisons?
Many thanks for responding, and apologies if I had failed to comply to etiquette of this platform, as this is my first step here, I am no programmer or statistician, just trying to learn a bit.
Regards, Prabhakar