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Benchmark Dose Software (BMDS)

About the MSW Time to Tumor Model

The multistage Weibull (MSW) time-to-tumor model and related documentation were developed principally (but not exclusively) for conducting time-to-tumor analyses to support risk assessments under the IRIS program. These programs and related documentation are made publically available to insure that the methods and calculations used for such analyses are transparent and reproducible. [I want more information about MSW]

Running MSW

The MSW time-to-tumor model is run from a Windows command prompt window, data is submitted in a text file, and output is sent to a text file. The executable (msw.exe) and data files must be saved in a directory (folder) of the user's choice. Users unfamiliar with command syntax should store these in the same directory (multiple directories for different projects).

Study the user manual before attempting to run the program. A spreadsheet template is provided to facilitate the process of correctly specifying run time options in the input file. For a quick start, jump to Appendices 1 and 2 of the User Manual.

The program has been tested under the Windows XP operating system with Service Pack 2.

NOTICE: (June 17, 2010): The msw executable has been updated to remove Expected counts from the table of response counts, because the Expected counts are believed to be in error; a corrected executable will be posted when ready. A second error regarding handling of "U" (Unknown) responses has been verified. The User Manual and technical documents state that "U" contexts are ignored when fitting the model for Nonfatal tumors. Instead, "U" observations are treated like "C" observations in the Nonfatal model. Users should omit any "U" observations from a data file before fitting a Nonfatal tumor model. A corrected executable will be posted when ready.

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