search for: horvitz

Hi, I am wondering if there is a package for doing conditional logistic regression for nested case-control study as described in "Estimation of absolute risk from nested case-control data" by Langholz and Borgan (1997) where Horvitz-Thompson sampling weight (log of (number in the risk set divided by the number sampled)) is used with regression. In SAS Proc Phreg, this is implemented as an offset (offset=logweight). I checked clogistic() in Epi package and clogit() in survival package, but couldn't figure out how to inco...

Hi, I want to generate 10000 samples from normal distribution with replacement case and every sample size is 50. What should I do ? -- View this message in context: http://r.789695.n4.nabble.com/IMPORTANT-PLEASE-HELP-ME-tp4650676.html Sent from the R help mailing list archive at Nabble.com.

Hello! I am using for logistic regression in survey data the svyglm procedure. I wondered how does the strata effect estimates SE (in addition to the weights given proportional to population size). I know that for simple regression measurements of each strata is assumed to have different variance. But in a logistic model this is not the case. Can anyone help me here? Thank you Ron [[alternative

Hello, I have some measurements that I am trying to fit a model to. I also have uncertainties for these measurements. Some of the measurements are not well detected, so I'd like to use a limit instead of the actual measurement. (I am always dealing with upper limits, i.e. left censored data.) I have successfully run survreg using the combination of well detected measurements and limits,

I have to the treatment effect base on the observational data.And the treatment variable is multinomial rather than binary.Because the treatment assignment is not random,so the selection-bias exists.Under this condition,what's the best way to estimate the treatment effect? I know that if the treatment is binary,I can use propensity score matching using MatchIt package.But what about

Dear All, I would like to find something ( references, code,..) to implement a comparison of three treatments in an observational study using the 'Propensity Score'. Any help is much appreciated. Thanks! Giovanni -- dr. Giovanni Parrinello Department of Biotecnologies Medical Statistics Unit University of Brescia Viale Europa, 11 25123 Brescia email: parrinel at med.unibs.it Phone:

Dear list, I am using svyglm in the survey library to fit a binomial logistic regression accounting for sample design. The documentation says the models are not fit by maximum likelihood, so my question is what is the fitting method? Pseudo likelihood? Generalized least squares? Thanks for any insight. Best, Corey Corey Sparks Assistant Professor Department of Demography and

Hello, I know that two possible approaches to dealing with clustered data would be GEE or a robust cluster covariance matrix from a standard regression. What are the differences between these two methods, or are they doing the same thing? Thanks. -- View this message in context: http://www.nabble.com/Difference-between-GEE-and-Robust-Cluster-Standard-Errors-tp22092897p22092897.html Sent from the

Dear R community I am using the gee package to run logistics regression on paired cases from a panel sample. We are getting request from a reviewer to use sample weights to account for different level of attrition. After searching the documentation I am unable to find a way to incorporate sample weights into the gee formula. I found a way to incorporate precision weight but I understand that I

...sed to a single observation in the data frame to save space. This is the assumption of survfit. (Most readers of this list will be too young to remember when computer memory was so small that we had to use tricks like this.) The second assumption is that the weights are sampling weights and a Horvitz-Thompsen like estimator should be used for variance. This is the assumption of the svykm program in the survey package. It appears you want the second behavior. Terry Therneau On 03/26/2013 06:00 AM, r-help-request at r-project.org wrote: > As part of a research paper, I would like to draw...

Hello, How I use the function as.svrepdesign without memory.size problems? desenho_npc_JK <- as.svrepdesign(desenho_npc,type="JKn") Error: cannot allocate vector of size 161.3 Mb In addition: Warning messages: 1: Reached total allocation of 1022Mb: see help(memory.size) 2: Reached total allocation of 1022Mb: see help(memory.size) 3: Reached total allocation of 1022Mb: