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CatReg Software for Categorical Regression Analysis (Feb 2011)
EPA is announcing an update to CatReg. The new CatReg version 2.2 will make it more compatible with the latest versions of the R program it is based on. Version 2.2 of CatReg and a "readme" file describing the changes it includes can be downloaded from the "get the report" link below. In the upcoming months, EPA will also be releasing a new Windows-based beta version (version 3.0 beta) of CatReg. Check this website again in future months to obtain important CatReg information such as software updates and details regarding upcoming training opportunities.
Citation:
CatReg Software for Categorical Regression Analysis (Feb 2011). U.S. Environmental Protection Agency, Office of Research and Development, National Center For Environmental Assessment, Research Triangle Park Office, Research Triangle Park, NC.
Impact/Purpose:
The software was developed to support toxicity assessment for acute inhalation exposures, but the U.S. Environmental Protection Agency (EPA) encourages the broad application of this software.
Description:
CatReg is a computer program, written in the R (http://cran.r-project.org) programming language, to support the conduct of exposure-response analyses by toxicologists and health scientists. CatReg can be used to perform categorical regression analyses on toxicity data after effects have been assigned to ordinal severity categories (e.g., no effect, adverse effect, severe effect) and associated with up to two independent variables corresponding to the exposure conditions (e.g., concentration and duration) under which the effects occurred. CatReg calculates the probabilities of the different severity categories over the continuum of the variables describing exposure conditions. The categorization of observed responses allows expression of dichotomous, continuous, and descriptive data in terms of effect severity and supports the analysis of data from single studies or a combination of similar studies.