NIOSH-IREP Software

The Department of Labor (DOL) uses a special computer program called NIOSH-IREP (Interactive RadioEpidemiological Program). This tool helps DOL determine the probability of causation (PC) for a cancer case under the Act. The PC measures how likely a worker’s radiation exposure caused their cancer.

The actual outcome of a case will depend on many important factors. For example, the outcome will depend on how much radiation a worker received and what kind of cancer they have.

NIOSH adapted NIOSH-IREP from the National Institutes of Health’s Interactive RadioEpidemiological Program (NIH-IREP). The National Cancer Institute developed NIH-IREP to update the 1985 NIH Radioepidemiological Tables.

NIOSH-IREP addresses the workforce covered by the Act. NIOSH tailored the program to the risks and radiation exposures of nuclear weapons employees. We maintain and update this software and the scientific elements (cancer risk models) that it uses.

Access and Use

Online Access

You can access the software program on the NIOSH-IREP website. Enter the data by hand or by using a NIOSH-provided input file. Users also can calculate PC from multiple primary cancers.

User’s Guide

• User’s Guide Version 6.0
  (August 2024)

  Here is a complete description with all the changes that we made in NIOSH-IREP v.6.0:

  1. Increased Number of Possible Exposures
     We expanded the number of possible exposures from 1,000 to 1,500. We also updated the Excel template file to reflect this change.

  2. Updated Template Format
     We digitally signed the Excel template file and saved it in a new format (.xlsm). This format allows us to embed macros in the template file. The macros provide the ability to hide unused rows of exposure. You can download files in the new format from the Upload Saved File page on the NIOSH-IREP website.

  3. Calculated PC from Radon Exposures Only
     To calculate PC for lung cancer claims from radon exposure only, enter a non-zero exposure to radon and zero exposures to other sources.

  4. Changed Default Sample Size
     We changed the default sample size from 2,000 iterations to 20,000 iterations.

  5. Upgraded Computational Platform
     We use the Analytica Decision Engine (ADE) as the underlying computational platform for NIOSH-IREP. We updated NIOSH-IREP to the most current version of ADE (v.6.3.6). One of the new features allows us to use multithreaded evaluation. This takes advantage of multiple cores on NIOSH-IREP servers to speed up net computation time. PC results obtained from NIOSH-IREP v.6.0 will be identical to those from NIOSH-IREP v.5.9.

Example Input Files

Below are example input files you can upload into NIOSH-IREP. Refer to the NIOSH-IREP User’s Guide for upload instructions. We also provide summaries of the example files. To work properly, you must first save the files to a disk or to your computer. From there, you can upload them directly into the program.

• Example 1a [(Microsoft Excel File; 233 KB)]

• Example 1b [(Microsoft Excel File; 233 KB)]

• Example 2a [(Microsoft Excel File; 233 KB)]

• Example 2b [(Microsoft Excel File; 234 KB)]

• Example 3 [(Microsoft Excel File; 234 KB)]

• Example 4 [(Microsoft Excel File; 234 KB)]

Technical Documentation

• NCI-CDC Working Group to Revise the 1985 NIH Radioepidemiological Tables [1.4 MB (126 pages)]

• NIOSH-IREP Technical Documentation [2.01 MB (77 pages)]

  • Pages i-20 [664 KB (24 pages)]

  • Pages 21-50 [771 KB (30 pages)]

  • Pages 51-73 [650 KB (23 pages)]

• Radiation Effectiveness Factors (REFs) for Use in Calculating Probability of Causation of Radiogenic Cancers [4.41 MB (77 pages)]

  • Pages 1-15 [896 KB (15 pages)]

  • Pages 16-30 [814 KB (15 pages)]

  • Pages 31-45 [996 KB (15 pages)]

  • Pages 46-60 [944 KB (15 pages)]

  • Pages 61-77 [883 KB (17 pages)]

Subject Matter Expert Review

• Comments from David G. Hoel, Ph.D., University Professor, Medical University of South Carolina. [157 KB (6 pages)]

• Comments from Richard Hornung, University of Cincinnati. [157 KB (4 pages)]

• Comments from David Richardson, Department of Epidemiology, School of Public Health, University of North Carolina. [52 KB (6 pages)]

• Comments from Roy E. Shore, Ph.D., Dr. P.H., Professor, Department of Environmental Medicine, Director, Division of Epidemiology and Biostatistics, New York University, School of Medicine. [164 KB (4 pages)]

• Comments from Daniel O. Stram, Ph.D., Associate Professor, Keck School of Medicine, Department of Preventive Medicine, Division of Biostatistics, University of Southern California. [439 KB (5 pages)]

• Response to Subject Matter Expert Review Comments on NIOSH-IREP [917 KB (27 pages)]

Previous Versions

Find information on previous updates on the NIOSH-IREP Updates page.

Submitting Comments

The public may comment on NIOSH-IREP at any time.

Email comments to:

dcas@cdc.gov.

Mail comments to:

NIOSH-IREP Comments
National Institute for Occupational Safety and Health (NIOSH)
Division of Compensation Analysis and Support (DCAS)
Robert A. Taft Laboratories, MS-C45
1090 Tusculum Avenue
Cincinnati, OH 45226

Frequently Asked Questions (FAQs)

Find more information on NIOSH-IREP on the FAQs: NIOSH-Interactive RadioEpidemiological Program (NIOSH-IREP) page of our website.