Displaying 20 results from an estimated 500 matches similar to: "LME as part of meta-analysis"
2007 Mar 12
4
meta-regression, MiMa function, and R-squared
Dear Wolfgang Viechtbauer and list members:
I have discovered your "MiMa" function for fitting meta-analytic
mixed-effects models through an earlier discussion on this list. I think
it is extremely useful and fills an important gap. In particular, since
it is programmed so transparently, it is easy to adapt it for one's own
needs. (For example, I have found it easy to identify
2007 Jun 21
3
meta-analysis in R
I would like to combine time-series data to test for correlations and
interactions using random and fixed effects meta-analysis.
So, I am looking for the right packages and documentation.
I know about meta and rmeta packages of R.
Are there any more? What are the diffrences in brief?
Can you please suggest some references that could be used as a guide for
meta-analysis in R (or S-plus)?
2006 Nov 09
2
Meta-regression with lmer() ? If so, how ?
Dear List,
I am (again) looking at meta-regression as a way to refine meta-analytic
results. What I want to do is to assess the impact of some fixed factors
on the results of a meta-analysis. Some of them may be crossed with the
main factor of the meta-analysis (e. g. clinical presentation of a
disease, defining subgroups in each of the studies under analysis), some
of them may be a grouping
2007 Jun 27
2
Meta-Analysis of proportions
Dear colleagues,
I'm conducting a meta-analysis of studies evaluating adherence of HIV-positive drug users into AIDS treatment, therefore I'm looking for some advice and syntax suggestion for running the meta-regression using proportions, not the usual OR/RR frequently used on RCT studies.
Have already searched already several handbooks, R-manuals, mailing lists, professors, but... not
2013 Jan 23
1
mixed effects meta-regression: nlme vs. metafor
Hi,
I would like to do a meta-analysis, i.e., a mixed-effects regression,
but I don't seem to get what I want using both the nlme or metafor packages.
My question: is there indeed no way to do it?
And if so, is there another package I could use?
Here are the details:
In my meta-analysis I'm comparing different studies that report a
measure at time zero and after a certain followup
2006 Mar 12
1
meta / lme
Hi
I'm conducing a meta-analysis using the meta package.
Here's a bit of code that works fine -
tmp <- metacont(samplesize.2, pctdropout.2, sddropout.2,
samplesize.1, pctdropout.1, sddropout.1,
data=Dataset, sm="WMD")
I would now like to control for a couple of variables (continuous and
categorical) that aren't in the equation.
Is meta
2009 Jul 24
1
metafor
I had found the author's (Wolfgang Viechtbauer) earlier meta-analytic code in R, MiMa, useful. so I have been exploring metafor using an example dataset from MiMa. metafor provides a lot more. However, MiMa provided parameter estimates, standard errors, z values, etc. for individual moderators in the meta-analysis, but I don't see how to obtain these from metafor. Have you any help
2009 May 06
1
Duplicating meta-regression results from PROC MIXED with lmer
R-experts:
In 2002, Hans Van Houwelingen et al. published a tutorial on how to do
meta-regression in Statistics in Medicine. They used the classic BCG
dataset of Colditz to demonstrate correct methodology and computed the
results using PROC MIXED in SAS. In trying to duplicate the results
presented in this paper, I have discovered that I can reproduce
certain items with lmer but not
2008 Jun 17
1
CIFS VFS errors on strtoUCS in messages log
I have little idea what actions this relates to,
but I see about 200 or more of these errors each day
in the messages log file:
May 29 15:55:41 mima kernel: CIFS VFS: strtoUCS: char2uni of -127 returned
-22
No one has complained of a problem. Does anyone know what
it signifies?
--Donald
2007 Oct 22
1
Meta-analysis mixed model
I have a meta-analysis dataset which I would like to analyze as a mixed
model, where the y-variable is a measure of effect size, the random effect
is the study from which the effect size was extracted, and the fixed
effect is a categorical explanatory variable. The complication is that we
often have multiple estimates of effect size from a single study (e.g. the
experiment was repeated in
2009 Jun 25
3
ANOVA with means and SDs as input
Dear R-community,
I'm struggling with a paper that reports only fragmented results of a
2by2by3 experimental design. However, Means and SDs for all cells are given.
Does anyone know a package/function that helps computing an ANOVA with only
Means and SDs as input (resulting in some sort of effect size and
significance test)?
The reason why I'm interested is simple: I'm conducting a
2004 May 11
1
Meta-Analysis using lme
Dear list-members,
I am trying to use R to conduct a meta-analysis, i.e. I'd like to use a
multi-level model to integrate the findings of a number of primary research
studies.
I set up a simple two level-model (only summary statistics are provided by
each study) as follows:
sapp.lme <- lme(D ~ 1, data = sapp.frame, random = ~ 1 | STUDYNR,
weights=varFixed(~-1+STDERR_D),na.action =
2009 Apr 29
1
meta regression in R using lme function
Dear all,
We are trying to do a meta regression in R using the lme function. The
reason for doing this with lme function is that we have covariates and
studies within references. In S-Plus this is possible by using the
following command:
lme(outcome ~ covars, random = ~1 | reference/study, weights =
varFixed(~var.outcome), data = mydata, control = lmeControl(sigma = 1))
This means that the
2010 May 27
3
how to extract the 1st field from a vector of strings
I have the following vector of strings (shown only the first 3 elements)
> desc[1:3]
[1] "hsa-let-7a MIMAT0000062 Homo sapiens let-7a"
[2] "hsa-let-7a* MIMAT0004481 Homo sapiens let-7a*"
[3] "hsa-let-7a-2* MIMAT0010195 Homo sapiens let-7a-2*"
> is.vector(desc)
[1] TRUE
> A <- unlist(strsplit(desc[1:3], " "))
> A
[1]
2009 Aug 13
1
metafor random effects meta-analysis
Hello,
Great to see the new metafor package for meta-analysis.
I would like to perform a meta-analysis in which I initially calculate the intercept of the model with a nested random-effects structure. In lme, this would be
model<- lme(v3~1, random=~1|species/study, weights = varFixed(~Wt), method = "REML")
where multiple effects sizes are measured for some studies and more than
2007 May 14
1
cross-validation / sensitivity anaylsis for logistic regression model
Hi,
I have developed a logistic regression model in the form of (factor_1~ numeric
+ factor_2) and would like to perform a cross-validation or some similar
form of sensitivity analysis on this model.
using cv.glm() from the boot package:
# dataframe from which model was built in 'z'
# model is called 'm_geo.lrm'
# as suggested in the man page for a binomial model:
cost <-
2007 Jun 14
2
Difference between prcomp and cmdscale
I'm looking for someone to explain the difference between these
procedures. The function prcomp() does principal components anaylsis,
and the function cmdscale() does classical multi-dimensional scaling
(also called principal coordinates analysis).
My confusion stems from the fact that they give very similar results:
my.d <- matrix(rnorm(50), ncol=5)
rownames(my.d) <-
2011 Feb 01
2
Scatterplot Question
Hello,
I have some data where a number of events (the total amount varies)
occur at cumulating times, I would like to create a scatterplot
(easily achieved using plot etc) of these events (the events can
either be times using poxist or I can convert them into just seconds
which is probably easier to work with), however I would like the
events/times to re-begin plotting every 10th occurrence and
2001 Oct 26
1
Getting started with Time Series
Anyone have a good R tutorial for time series? Or know
of a good book? Any advice would be helpful. I've
been using matlab and programming things directly (not
using canned functions), but now I'm having difficulty
figuring out how to say, do freq domain anaylsis and
get a CI on my periodogram, or plotting the coherence,
etc. Or how to change certain parameters, e.g. fit
AR(p) with p
2006 Jan 26
0
Local Channel Call Looping
*** If anyone has a better way of doing this, please post to the list. I
hadn't seen anything on this list or in channel.c/chan_local.c - which
prompted this email ***
I'm not sure how many VoIP providers out there are using Asterisk as a
service platform like we do, but I thought I'd share an experience with
call looping that was racking my brain with the list.
One of the