Publications by Ewen Harrison
R function to retrieve pubmed citations from pmid number
This is useful number if you have hundreds of PMIDs and need specific fields from the pubmed/medline citation.################################# # Retrieve pubmed citation data # # Ewen Harrison # # March 2013 # # www.datasurg.net # ################################# # Sample data pmid<-c(8339401,848...
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Install R
Video Files This file contains data on pain score after laparoscopic vs. open hernia repair. Age, gender and primary/recurrent hernia also included. The ultimate aim here is to work out which of these factors are associated with more pain after this operation. lap_hernia Script ########################## # Getting started with R # # Ewen Harriso...
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Organise your data
Use R to specify factors, recode variables and begin by-group analyses. Video Files This file contains data on pain score after laparoscopic vs. open hernia repair. Age, gender and primary/recurrent hernia also included. The ultimate aim here is to work out which of these factors are associated with more pain after this operation. lap_hernia Scr...
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Mortality after paediatric heart surgery using public domain data
This post comes with some big health warnings. The recent events in Leeds highlight the difficulties faced in judging the results of surgery by individual hospital. A clear requirement is timely access to data in a form easily digestible by the public. Here I’ve scraped the publically available data from the central cardiac audit database (CCAD...
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A map of the world by tweets
With geo-tagging enabled, tweets include information on the location of the user when the tweet was sent. Miguel Rios (@miguelrios) has plotted locations of billions of tweets to create maps of the world. This is pretty amazing stuff – a world map rendered just from twitter posts! Maps are created using every tweet from 2009 using R and the ggm...
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Bayesian statistics and clinical trial conclusions: Why the OPTIMSE study should be considered positive
Statistical approaches to randomised controlled trial analysis The statistical approach used in the design and analysis of the vast majority of clinical studies is often referred to as classical or frequentist. Conclusions are made on the results of hypothesis tests with generation of p-values and confidence intervals, and require that the correc...
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RStudio and GitHub
Version control has become essential for me keeping track of projects, as well as collaborating. It allows backup of scripts and easy collaboration on complex projects. RStudio works really well with Git, an open source open source distributed version control system, and GitHub, a web-based Git repository hosting service. I was always forget how...
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An alternative presentation of the ProPublica Surgeon Scorecard
ProPublica, an independent investigative journalism organisation, have published surgeon-level complications rates based on Medicare data. I have already highlighted problems with the reporting of the data: surgeons are described as having a “high adjusted rate of complications” if they fall in the red-zone, despite there being too little dat...
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P-values from random effects linear regression models
lme4::lmer is a useful frequentist approach to hierarchical/multilevel linear regression modelling. For good reason, the model output only includes t-values and doesn’t include p-values (partly due to the difficulty in estimating the degrees of freedom, as discussed here). Yes, p-values are evil and we should continue to try and expunge them f...
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Install github package on safe haven server
I’ve had few enquires about how to install the summarizer package on a server without internet access, such as the NHS Safe Havens. Upload summarizer-master.zip from here to server. Unzip. Run this: library(devtools) source = devtools:::source_pkg("summarizer-master") install(source) Related To leave a comment for the author, please follo...
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