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Bone Marrow Transplantation (2013) 48, 452458 & 2013 Macmillan Publishers Limited All rights reserved 0268-3369/13
http://www.nature.com/bmt
Web End =www.nature.com/bmt
TECHNICAL REPORT
Investigation of the freely available easy-to-use software EZR for medical statistics
Y Kanda
Although there are many commercially available statistical software packages, only a few implement a competing risk analysis or a proportional hazards regression model with time-dependent covariates, which are necessary in studies on hematopoietic SCT. In addition, most packages are not clinician friendly, as they require that commands be written based on statistical languages. This report describes the statistical software EZR (Easy R), which is based on R and R commander. EZR enables the application of statistical functions that are frequently used in clinical studies, such as survival analyses, including competing risk analyses and the use of time-dependent covariates, receiver operating characteristics analyses, meta-analyses, sample size calculation and so on, by point-and-click access. EZR is freely available on our website (http://www.jichi.ac.jp/saitama-sct/SaitamaHP.files/statmed.html
Web End =http://www.jichi.ac.jp/saitama-sct/SaitamaHP.les/statmed.html) and runs on both Windows (Microsoft Corporation, USA) and Mac OS X (Apple, USA). This report provides instructions for the installation and operation of EZR.
Bone Marrow Transplantation (2013) 48, 452458; doi:http://dx.doi.org/10.1038/bmt.2012.244
Web End =10.1038/bmt.2012.244 ; published online 3 December 2012
Keywords: statistical software; EZR; competing risk; time-dependent covariate
INTRODUCTIONThere are many commercially available statistical software packages, including SAS (SAS Institute Inc., Cary, NC, USA), SPSS (SPSS Inc., Chicago, IL, USA) and Stata (Stata Corporation, College Station, TX, USA). These packages are widely used in the area of medical statistics.1 However, some of these packages do not implement a competing risk analysis or proportional hazards regression model with time-dependent (TD) covariates, which are necessary in studies on hematopoietic SCT.24 In addition, most packages are not clinician friendly, as they require that commands be written based on statistical languages. R is an open-source freely available software environment for statistical computing and graphics.5 R supports many functions for statistical analyses, but also requires that the user write commands based on the S statistical language. R commander provides an easy-to-use basic-statistics graphical user interface for R.6 However, the statistical functions of R commander are limited, especially those in the eld of medical statistics. Therefore, I added statistical functions, such as survival analyses, including competing risk analyses and the use of TD...