search for: epidemiologists

Hi everybody, recently I had to teach a course on Cox model, of which I am not a specialist, to an audience of medical epidemiologists. Not a good idea you might say.. anyway, someone in the audience was very hostile. At some point, he sayed that Cox model was useless, since all you have to do is count who dies and who survives, divide by the sample sizes and compute a relative risk, and if there was significant censoring, use cum...

I contacted John Fox about this first, because parts of the file are attributed to him. He says that he didn't write rstandard.glm(), and suggests asking r-devel. As it stands, rstandard.glm() has summary(model)$dispersion outside the sqrt(), while in rstandard.lm(), the sd is already sqrt()ed. This seems to follow stdres() in VR/MASS/R/stdres.R. Of course for the c("poisson",

Dear R users, I am encoutering the following problem: I have a dataset with a 'unique_id' and different 'visit_date' (formatted as.Date, "%d/%m/%Y") per unique_id. I would like to create a new variable with the most recent date of visit per unique_id as shown below. unique_id visit_date last_visit_date 1 01/06/2010 01/06/2011 1 01/01/2011 01/06/2011 1

Thank you to all who made very helpful suggestions to get started with R. Duncan Murdoch raised an excellent question, asking about my background and reason for using R. I'm an epidemiologist, applying the marginal structural models approach (inverse probability of treatment weights) in a Cox proportional hazards analysis. The statistical program which I had been using does not have

Dear there, I am working on the NHANES survey data, and want to apply quantile regression on these complex survey data. Does anyone know how to do this? Thank you in advance, Yiling Cheng Yiling J. Cheng MD, PhD Epidemiologist CoCHP, Division of Diabetes Translation Centers for Disease Control and Prevention 4770 Buford Highway, N.E. Mailstop K-10 Atlanta, GA 30341 [[alternative HTML

Hi, I am using many comment lines like this # a comment line in a script. Is there any way to print comment lines when I use sink() function? Or, are there any plans to include as an option to sink() function in the near future? I would not want to use cat() function as it will look messy in the original script file. Thanks! SI __________________________________________________

Greetings. Yesterday I decided to try out Rcmdr, but it refused to load. I traced the problem to the library tcltk, which when I tried to load it told me this: > > library(tcltk) > Loading Tcl/Tk interface ... Error in fun(...) : > Can't find a usable init.tcl in the following directories: > @TCL_IN_FRAMEWORK@ @TCL_IN_FRAMEWORK@ > > > > This probably

Hi, I would like to use sweep to "sweep out" proportions and confidence intervals for an array, however when I supply a function which returns a string (containing something like "9% (3-18%)") I get back a list instead of an array, here is a simplified example: # example showing that sweep does not return an array with same dimensions as STATS as advertised

Greetings to all, and my apologies for a question that is mostly about statistics and secondarily about R. I have just started a new job that (this week, apparently) requires statistical knowledge beyond my training (as an epidemiologist). The problem: - We have 57 food production facilities in three categories - Samples of 4-6 different foods were tested for listeria at each facility - I need

Hi all I hope you might help me with some aspects of producing a graph in lattice. There are three things I have struggling with and that is: 1. to separate the horizontal box rows from each other; 2. to change the colour of the horizontal and vertical strips to white; and 3. to place the axes labels on the left y axes and on the bottom x axes. I would really appreciate some help. I have put the

I think it is easiest to describe what I want in terms of the concrete problem I have. I have data from a number of countries in each of which a sample of people was interviewed. In presenting the results in a forthcoming collaborative publication much emphasis will be placed on the multi-centre nature of the study. Although I suspect colleagues may do this with shaded maps I would prefer to

...version.string R version 2.5.0 (2007-04-23) Package: epitools Version: 0.4-8 Date: 2007-05-10 Title: Epidemiology Tools Author: Tomas Aragon <aragon at berkeley.edu> Maintainer: Tomas Aragon <aragon at berkeley.edu> Depends: R (>= 2.1.0) Description: A package of analytic tools for epidemiologists. License: GPL version 2 or newer URL: http://www.epitools.net Packaged: Thu May 10 01:55:28 2007; Tomas Built: R 2.5.0; ; 2007-05-10 14:22:09; windows (at home) > epitab(matrix(c(227,473,74,126),2)) Warning: a final empty element has been omitted the part of the args list of 'list' bei...

Dear colleagues, I'm an epidemiologist with no background in programming and just started using R a few weeks ago. I am working on the epidemiology of African sleeping sickness, and am trying to use R to perform a Monte Carlo Markov Chain analysis to estimate three unknown parameters within a model of African sleeping sickness case detection that is mainly informed by actual field programme

...different sources in different formats and has often had minimal cleaning or processing before we receive it. The data providers often provide flat files which are processed in Python and translated to database format. Our analytics team comprises machine learning specialists, biostatisticians and epidemiologists. The key responsibilities of the post are to liaise with those providing the data to help them provide it in an appropriate format and to assist in the warehousing of the data including processing and documenting the data to make it ready for the analytics team. Essential attributes are good interp...

...ethods and Kulldorff & Nagarwalla's statistic) and a focused test (Stone's Test). Bootstrap is used to estimate significance and a number of models are proposed to simulate data: permutations and Poisson, Multinomial or Neg. Binomial distributions. I hope the package will be useful to epidemiologists and statisticians involved in spatial epidemiological studies. As usual, feedback and comments are welcome. Our hope is to improve the package, so suggestions about new methods to be added are of interest. With best regards, -- Virgilio G?mez Rubio Grup d'Estad?stica espacial i...

Dear R Community, I would like to announce the package "surveillance", which provides methods for the surveillance of count data time series originating from the routine collection of public health data. The package addresses epidemiologists and statisticians working with routine surveillance, but it also offers an infrastructure for developers of new detection algorithms. Implemented outbreak detection algorithms are: * Stroup et al. (1989) * Farrington et al. (1996) * A Bayesian predictive posterior approach * Time varying Poisson m...

...ethods and Kulldorff & Nagarwalla's statistic) and a focused test (Stone's Test). Bootstrap is used to estimate significance and a number of models are proposed to simulate data: permutations and Poisson, Multinomial or Neg. Binomial distributions. I hope the package will be useful to epidemiologists and statisticians involved in spatial epidemiological studies. As usual, feedback and comments are welcome. Our hope is to improve the package, so suggestions about new methods to be added are of interest. With best regards, -- Virgilio G?mez Rubio Grup d'Estad?stica espacial i...

Course in STATISTICAL PRACTICE IN EPIDEMIOLOGY USING R ==================================================== Tartu, Estonia, 26 - 31 May 2005 The course is aimed at epidemiologists and statisticians who wish to use R for statistical modelling and analysis of epidemiological data. The course requires basic knowledge of epidemiological concepts and study types. These will only be briefly reviewed, whereas the more advanced epidemiological and statistical concepts will be treate...

Ilija Barukcic, Jever, Germany. GMT + 1h. Barukcic at t-online.de Hallo, you are receiving this message from me as someone who potentially has bought the first Edition of my book Causality. New statistical methods. ISBN 3 - 8 3 3 4 - 3 6 4 5 - X. Your email address was obtained either through my friends, your publication, a colleague or via correspondence with you. I am pleased to

Dear R Community, I would like to announce the package "surveillance", which provides methods for the surveillance of count data time series originating from the routine collection of public health data. The package addresses epidemiologists and statisticians working with routine surveillance, but it also offers an infrastructure for developers of new detection algorithms. Implemented outbreak detection algorithms are: * Stroup et al. (1989) * Farrington et al. (1996) * A Bayesian predictive posterior approach * Time varying Poisson m...