Common mistakes in R programming
The R Inferno
Tuesday, September 28, 2010
Wednesday, September 22, 2010
Critical Chain Project Management
In CCPM two durations are estimated for each: an aggressive duration based on how long the task would take given full focus on the task and no problems, and a “safe” duration given full focus and typical variation with each task. The differences between aggressive and “safe” durations for each critical task contribute to a pooled “project buffer” which is adjusted for the project as a whole. The end of the project buffer is the team’s “commit date” and the buffer protects the project from uncertainty
Managers and leadership need to provide clear project and task priorities and a work environment that enables single-task focus, so that each task can be completed quickly and with high quality.
Managers and leadership need to provide clear project and task priorities and a work environment that enables single-task focus, so that each task can be completed quickly and with high quality.
Tuesday, September 21, 2010
meta analysis
Jadad scale to measure methological quality of a clinical trial
tool: CMA
publication standards: quorum (eg) and moose (eg)
proc mixed can be used in meta analysis.
tool: CMA
publication standards: quorum (eg) and moose (eg)
proc mixed can be used in meta analysis.
Wednesday, September 15, 2010
histogram alternatives
Beanplot
hist() + rug(): add one dimensional scatter plot below the histograms
for discrete data: barplot(table(a)), where a is a discrete vector. Or barplot (tabulate (a))
ecdf (Empirical CDF) summarizes the data into something like a smooth CDF line while graphing all the data points.
dhist in ggplot2
more discussion from Gelman here and also here
hist() + rug(): add one dimensional scatter plot below the histograms
for discrete data: barplot(table(a)), where a is a discrete vector. Or barplot (tabulate (a))
ecdf (Empirical CDF) summarizes the data into something like a smooth CDF line while graphing all the data points.
dhist in ggplot2
more discussion from Gelman here and also here
Wednesday, August 25, 2010
main effect of a continous variable
In both proc mixed and glimmix (see the code example below), the "Solution for Fixed Effects" generated by option /SOLUTION for the continous variable 'binary' does not estimate the main/marginal effect when the value of binary changes from 0 to 1. It is because of the interaction term between binary and visit. To find the main/marginal effect, we can code the variable 'binary' as a class/categorical variable and find this LSMEANS.
Wednesday, July 28, 2010
Wednesday, June 23, 2010
Friday, June 18, 2010
Thursday, May 20, 2010
Thursday, May 13, 2010
matching program
Case control matching, probably implementing the idea of propensity scores
R
matchIT
Matching
optmatch optmatch presentation1; optmatch presentation2;
SAS
gmatch,vmatch,dist
a sugi paper 165-29: Performing a 1:N Case-Control Match on Propensity Score
PaperOn the Estimation and Use of Propensity Scores in Case-Control and Case-Cohort Studies
[using] cases plus controls in a case-control study... should give consistent estimates of the true propensity score under the null hypothesis, but not otherwise.
R
matchIT
Matching
optmatch optmatch presentation1; optmatch presentation2;
SAS
gmatch,vmatch,dist
a sugi paper 165-29: Performing a 1:N Case-Control Match on Propensity Score
PaperOn the Estimation and Use of Propensity Scores in Case-Control and Case-Cohort Studies
[using] cases plus controls in a case-control study... should give consistent estimates of the true propensity score under the null hypothesis, but not otherwise.
Tuesday, May 11, 2010
good clinical trial simulation practices
http://cdds.ucsf.edu/research/sddgpreport.php#_Toc457223476
Monday, May 10, 2010
A Draft Sequence of the Neandertal Genome.
http://www.researchblogging.org/post/gotourl/id/213933
http://www.researchblogging.org/post/gotourl/id/213689
http://www.researchblogging.org/post/gotourl/id/213509
http://www.researchblogging.org/post/gotourl/id/213689
http://www.researchblogging.org/post/gotourl/id/213509
Viagra could help women too
http://www.helenjaques.co.uk/blog/2010/viagra-breast-cancer-drug-delivery/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+Insicknessandinhealth+%28In+sickness+and+in+health%29
Researchers in California have shown that sildenafil (Viagra) and a similar drug called vardenafil can improve the delivery of the chemotherapeutic drug Herceptin (trastuzumab) in women with breast cancer that has spread to the brain.
Researchers in California have shown that sildenafil (Viagra) and a similar drug called vardenafil can improve the delivery of the chemotherapeutic drug Herceptin (trastuzumab) in women with breast cancer that has spread to the brain.
PubMed vs. Google Scholar
http://www.researchblogging.org/post/gotourl/id/214477
http://neurodojo.blogspot.com/2010/05/pubmed-vs-google-scholar.html?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+Neurodojo+%28NeuroDojo%29
http://neurodojo.blogspot.com/2010/05/pubmed-vs-google-scholar.html?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+Neurodojo+%28NeuroDojo%29
Antidepressants Not Effective for Some Types of Depression
http://www.researchblogging.org/post/gotourl/id/214478
http://brainblogger.com/2010/05/10/antidepressants-not-effective-for-some-types-of-depression/
http://brainblogger.com/2010/05/10/antidepressants-not-effective-for-some-types-of-depression/
Friday, April 30, 2010
Biomarkers and surrogate endpoints
A good article discussing surrogate endpoints and the gap between scientific theory and clinical benefit.
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