Interactive RadioEpidemiological Program
NIOSH-IREP v.5.8.1


NIOSH-IREP 5.8.1 Upgrade (03/28/18)

1. Intermediate Results
Intermediate Results and Importance Analyses have been moved to an expandable section at the bottom of the Summary Report. Past versions of NIOSH-IREP presented these results on separate pages under the "Model Details" section.

NIOSH-IREP 5.8 Upgrade (12/16/15)

1. Updated to 64-bit Host Server
The underlying computational platform used for NIOSH-IREP is known as Analytica Decision Engine (ADE). Earlier versions of NIOSH-IREP have relied on a 32-bit version of ADE (version 3.0). In order to increase the capabilities of NIOSH-IREP, including the ability to evaluate claims with large numbers of exposures, NIOSH-IREP 5.8 is now hosted on a 64-bit server running the most recent 64-bit version of ADE (version 4.6.1).

The computational speed of NIOSH-IREP 5.8 (64-bit) is now approximately 5 times faster than calculations performed with NIOSH-IREP 5.7.1 (32-bit).

PC results obtained from NIOSH-IREP 5.8 will be similar (but not identical) to the same claim evaluated on previous versions. This small variation is due to the use of a more efficient random number generator implemented in the latest ADE software.

2. Changed Minimum Exposure Age
The original domain of application of NIOSH-IREP included the ability to estimate Probability of Causation (PC) for exposures to radiation at ages 15 or greater. The minimum exposure age was lowered to 14 years in NIOSH-IREP 5.7.1 and is being reduced to 10 years in NIOSH-IREP 5.8.

NIOSH-IREP 5.7.1 Upgrade (07/21/14)

1. Changed Minimum Exposure Age
The original domain of application of NIOSH-IREP included the ability to estimate Probability of Causation (PC) for exposures to radiation at ages 15 or greater. The minimum exposure age has now been lowered to 14 years.

2. Increased Number of Multiple Primary Cancers
The maximum number of primary cancers allowed by NIOSH-IREP was increased from 120 to 240.

3. Improved Accessibility for Multiple Primary Cancers Input Screen
The Multiple Primary Cancers Input screen was modified to operate with recent versions of commonly-used web browsers (2014 and earlier versions of Internet Explorer, Chrome, Safari, and Firefox).

NIOSH-IREP 5.7 Upgrade (01/24/13)

1. Added Chronic Lymphocytic Leukemia Risk Model
NIOSH has reviewed the current literature and epidemiological data on the relationship between radiation and Chronic Lymphocytic Leukemia (CLL) and proposed that CLL be considered as a radiogenic cancer under the Energy Employees Occupational Illness Compensation Program Act of 2000 (EEOICPA). A risk model has been developed for estimating Probability of Causation. The newly-developed risk model has passed the review process and is now incorporated in NIOSH-IREP. For more information on this topic, click here.

2. Added 3-Parameter Lognormal Distribution Option
Dose reconstructions have identified scenarios where a claimant's dose is best represented by a 3-parameter lognormal distribution. The first 2 parameters remain unchanged (geometric mean and geometric standard deviation). Users now have the ability to enter a 3rd parameter (location) to describe a lognormal distribution in the dose input table. The location parameter is sometimes called a "shift" parameter.

3. Added Weibull Distribution Option
Dose reconstructions have identified scenarios where a claimant's dose is best represented by a Weibull distribution. Users now have the ability to select a Weibull distribution in the dose input table, described by 3 parameters. Enter "Shape" for Parameter 1, "Scale" for Parameter 2, and "Location" for Parameter 3 (optional).

NIOSH-IREP 5.6 Upgrade (09/21/09)

1. Corrected Acute Lymphocytic Leukemia Algorithm
During recent quality control verification calculations, it was identified that NIOSH-IREP contained an incorrect algorithm for a specific set of input parameters used when processing acute lymphocytic leukemia claims. For all types of leukemia (including acute lymphocytic leukemia), in the case of acute exposure to low-LET radiation, the dose response obtained from the epidemiological data is linear-quadratic. Therefore, the ERR should be a function of [dose*(1+dose)]. In versions of NIOSH-IREP prior to v.5.6, the ERR for acute lymphocytic leukemia was programmed to depend only on dose instead of using the linear-quadratic algorithm. This modification has the potential to slightly increase the PC results for acute lymphocytic leukemia claims, if the claim included acute exposures to low-LET radiation.

2. Corrected Age Dependency for Selected Cancers
The recent quality control verification calculations identified a small difference between the NIOSH-IREP code and its documentation. The difference occurred in an algorithm that models the uncertainty in the adjustment factor describing the dependency of risk on age at exposure and attained age for cancer types included in Group 2. The NIOSH-IREP code has been modified to match the documentation. The PC values estimated for Group 2 cancers using NIOSH-IREP v.5.6 are identical to the results obtained from previous versions of NIOSH-IREP for any cancers diagnosed at ages 50 or older, and for any radiation exposures that occurred at ages 30 or older. However, the modification has the potential of slightly reducing the uncertainty in the estimated PC for exposures at ages less than 30 and for cancers diagnosed at ages less than 50. Testing with NIOSH-IREP v.5.6 indicated that the decrease in the 99th percentile of PC introduced by this modification is small (i.e., comparable or smaller than the variation introduced by a change in the random seed value).

3. Corrected Age Dependency for NIH Lung Model
The programming of the algorithm that describes the uncertainty in the adjustment factor for the dependency of risk on age at exposure and attained age for the NIH lung model was different from the algorithm given in the documentation of the code. In versions of NIOSH-IREP prior to v.5.6, there were two signs (+/-) that were reversed in an algorithm for males. This modification is expected to have little or no effect on PC results for males with lung cancer and will cause no change in PC estimates for males with exposures occurring at ages greater than 30 and a diagnosed lung cancer at age 50 or greater. This modification will cause no change in PC estimates for females with lung cancer.

4. Multiple Primary Cancers Link on Initial Screen
A button was added to the initial login screen on NIOSH-IREP to allow a user to directly access the calculation that estimates the PC from multiple primary cancers. In versions of NIOSH-IREP prior to v.5.6, the link to the multiple primary cancer calculation was located at the bottom of the main input screen.

NIOSH-IREP 5.5.3 Upgrade (01/05/09)

1. "Claimant SSN" Reference Modified
The title of the input labeled "Claimant SSN" has been modified to "DOL Case No". This change was made in the Excel template file, on the main IREP input page, and on the summary page.

2. Dose Rounding Algorithm on Summary Page
It was requested by Health Physicists at NIOSH that the dose input parameters that are summarized on the "Summary Report" page be rounded to 3 significant figures. Prior versions of NIOSH-IREP reported all digits of the dose parameters, which sometimes caused the summary report to take many pages of paper to print. If the dose value is less than 0.001 or larger than 1000 cSv, exponential format is now used in the dose summary table.

NIOSH-IREP 5.5.2 Upgrade (06/13/07)

1. Expanded Multiple Primary Calculation Capabilities
Prior to 06/13/07, the Multiple Primary Cancer calculation in NIOSH-IREP (located at the bottom of the main input screen) was capable of handling up to 12 primary cancers. Because there have been claims that consist of more than 12 primary cancers, the calculator has been upgraded to estimate Total PC for up to 120 primary cancers. These modifications do not affect the PC results whatsoever. The PC results given for a claim processed using NIOSH-IREP 5.5.2 will be exactly the same as if this claim were processed using NIOSH-IREP 5.5.1.

NIOSH-IREP 5.5.1 Upgrade (05/16/06)

1. Filename Displayed on Summary Page
Based on a recommendation made by a user from the Department of Labor, the name of the Excel template file that was uploaded for a given run is now displayed on the summary page. This will make it easier to distinquish between printed summary pages for claims with multiple cancers.

2. Memory and Speed Improvements
Due to the need to process claims with between 500 and 1,000 exposures, it became necessary to research ways to streamline the underlying NIOSH-IREP source code to make it more efficient. Modifications have been made in this upgrade that result in NIOSH-IREP requiring 30-40% less memory on the server that houses it. As an added bonus, the speed has been increased by 10-20%. These modifications do not affect the PC results whatsoever. The PC results given for a claim processed using NIOSH-IREP 5.5.1 will be exactly the same as if this claim were processed using NIOSH-IREP 5.5.

NIOSH-IREP 5.5 Upgrade (02/28/06)

1. Combined Lung Model
As of 02/28/06, NIOSH-IREP automatically runs lung cancer claims under both the NIOSH-IREP risk model and the NIH-IREP risk model and reports the set of results associated with the higher PC value at the 99th percentile. The higher PC value determines the claim outcome. (NOTE: For comparison purposes only, the lower PC value will be footnoted in the IREP Summary.) The only claims affected by this upgrade are those in which the NIOSH-IREP "Lung (162)" risk model is used. This change was presented to and endorsed by the Advisory Board on Radiation and Worker Health at their October 2005 meeting in Knoxville, TN.

2. Random Errors in Dosimetry for Radon Exposures
The radon model in previous versions of NIOSH-IREP contained a bias correction factor for random errors in dosimetry for smokers. In collaboration with the National Cancer Institute, it has been determined that the bias correction factor should also be applied for individuals who have never smoked. This modification, which affects only lung cancer claims for never smokers who were exposed to radon, has the potential to increase the 99th percentile of PC. The actual effect upon PC varies according to the level of exposure to radon. (Note: PC values cannot decrease as a result of this change. The effect, if any, upon a given claim would be to increase PC.) The same modification was made to NIH-IREP in 2005.

NIOSH-IREP 5.4 Upgrade (1/19/05)

1. Modification for thyroid cancer
Previous versions of NIOSH-IREP contained a reduction of the risk coefficients for thyroid cancer for ages less than 20 to account for a perceived difference in the dose response from exposure to x-rays and the dose response from exposure to high-energy gamma rays. More recent interpretation of the epidemiologic data on thyroid cancer from exposure to x-rays indicates that such a reduction is not necessary and should be removed from NIOSH-IREP. This modification only affects individuals with thyroid cancer who were exposed at ages less than 20 and leads to an increased probability of causation.

2. Modification for bone cancer
Previous versions of NIOSH-IREP assumed a latency period for bone cancer of approximately 10 years, similar to the latency period of other solid tumors. More recent interpretation of epidemiologic studies indicates that bone cancer can occur as early as 5 years after exposure to radiation, similar to thyroid cancer. This finding requires a reduction in the latency period assigned for bone cancer in NIOSH-IREP from that of solid tumors (about 10 years) to that of thyroid cancer (about 5 years). This modification only affects individuals who developed bone cancer within about 10 years after exposure to radiation and leads to an increased probability of causation.

3. Comma in Random Seed numbers
Users of NIOSH-IREP identified that typing a number with or without a comma as a random seed in the "Advanced Features" input screen produced different PC results. It was identified that the program viewed numbers with commas differently than it viewed numbers with no commas. A modification has been made to NIOSH-IREP It now gives the same PC results whether the user puts in commas or not (even if the commas are in the wrong place).

4. "New Calculation" Button
Users of NIOSH-IREP identified an issue with using the "New Calculation" button located on the Summary Results page. It was discovered that if the results from the first calculation were saved and the "New Calculation" button was used for the second and subsequent cancers, the saved results for each run were identical to that of the first run, even though the correct results were displayed on the screen. This issue is believed to be related to the browser settings on the user's machine. Most WWW browsers will cache or keep a local copy of your pages to speed-up future viewing of those pages. When a single session was opened with the NIOSH-IREP server and multiple runs were performed, the browser remembered the contents of the results page from the first time in displayed it. The browser does this to save downloading time. This issue is being researched. In the meantime, the "new calculation" button has been removed.

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If you have questions, please contact NIOSH