mtrank | R Documentation |
This function fits the Davidson-Bradley-Terry ranking model and produces a treatment hierarchy based on the method described by Evrenoglou et al. (2024) for network meta-analysis.
mtrank(x, level = x$level, ...)
## S3 method for class 'mtrank'
print(
x,
sorting = "ability",
backtransf = FALSE,
digits = gs("digits"),
digits.prop = gs("digits.prop"),
...
)
x |
An object of class |
level |
The level used to calculate confidence intervals for ability estimates. |
... |
Additional arguments (passed on to
|
sorting |
An argument specifying the criterion to sort the ability estimates in the printout (see Details). |
backtransf |
A logical argument specifying whether to show log-ability
estimates ( |
digits |
Minimal number of significant digits for ability estimates,
see |
digits.prop |
Minimal number of significant digits for proportions,
see |
This function fits a Davidson-Bradley-Terry model to the treatment preferences
tcc
function. It estimates the ability of
each treatment to outperform the other treatments in the network, along with
the respective standard errors, using a maximum likelihood approach.
The term 'ability to outperform' refers to a latent characteristic that
indicates the propensity of each treatment in the network to yield clinically
relevant and beneficial treatment effects, in the context of the defined
treatment choice criterion, when compared to the rest of the treatments.
Consequently, treatments with larger ability estimates are ranked more
prominently in the treatment hierarchy.
To retain identifiability, the maximization of the log-likelihood takes place subject to the constrain that the ability estimates sum to 1. Then, the maximum likelihood estimates (MLEs) are calculated iteratively. Note that the final estimates of the ability parameters are not necessarily needed to sum to 1 as after the first iteration of the algorithm the ability estimates are not normalized. However, by normalizing the final ability estimates to sum up to 1 these can be interpreted as "the probability that each treatment is having the highest ability".
Finally, a parameter "v" controlling the prevalence of ties in the network
is also estimated. Although the estimated values of this parameter do not
have a direct interpretation they are useful for estimating the fitted
pairwise probabilities (see fitted.mtrank
).
A data frame containing the resulting log-ability estimates, their standard errors and their confidence intervals.
The estimate of the tie prevalence parameter v, on the log-scale.
The normalized ability estimates for each treatment.
Evrenoglou T, Nikolakopoulou A, Schwarzer G, Rücker G, Chaimani A (2024): Producing treatment hierarchies in network meta-analysis using probabilistic models and treatment-choice criteria, https://arxiv.org/abs/2406.10612
data("antidepressants")
#
pw <- pairwise(studlab = studyid, treat = drug_name,
n = ntotal, event = responders,
data = antidepressants, sm = "OR")
# Use subset to reduce runtime
pw <- subset(pw, studyid < 60)
#
net <- netmeta(pw, reference.group = "tra")
ranks <- tcc(net, swd = 1.20, small.values = "undesirable")
#
fit <- mtrank(ranks)
# Print log-ability estimates
fit
#
# Print ability estimates
print(fit, backtransf = TRUE)
# Visualize results
forest(fit)
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