National Institute for Occupational Safety and Health

Revision to 42 CFR pt. 81

Changing from ICD-9 to ICD-10

David Allen

Health Physicist

Advisory Board on Radiation and Worker Health, 128th Meeting

Oak Ridge, Tennessee

August 21, 2019
Revision to 42 CFR pt. 81

 42 CFR pt. 81 is commonly referred to as our probability of causation rule

 The revision to the rule is primarily to convert references of ICD-9 to ICD10 but also includes:

– Update a reference to 20 CFR 30.5

– Removing a definition for the term “non-radiogenic cancer”
ICD Background

 International Classification of Diseases is a coding system of all diseases 

issued by the World Health Organization (WHO)

 ICD-9, the 9th revision to the system, has been replaced by ICD-10, the 10th

revision
 In the United States, the Clinical Modification (CM) version is used

 The CM version was developed by the National Center of Health Statistics 

(NCHS) and the Centers for Medicare and Medicaid Services (CMS)

 ICD-10-CM became effective October 1, 2015

 Annual updates to the ICD-CM have occasionally added additional cancer 

codes 

– When this occurs, the Coordination and Maintenance Committee 

(NCHS and CMS) issue a crosswalk describing the new code and listing 

the previous code applicable to that cancer

ICD Background (continued)
Use of ICD codes

 In EEOICPA, DOL verifies and classifies cancers using ICD codes

 DCAS uses the DOL classifications to determine the appropriate organs for 

internal and external dose calculations as well as selecting the appropriate 

cancer risk model 

 The designated organs and cancer risk models are contained in ORAUTOTIB-0005
Cancer Models

 The cancer risk models designated in ORAUT-OTIB-0005 originally come 

from the technical documentation for the NIOSH version of Interactive 

RadioEpidemiological Program (NIOSH-IREP)

 When the CM version is updated to add new cancer codes, NCHS and CMS

issue a crosswalk describing the new code and listing the previous code 

applicable to that cancer

 The cancer risk model to be used for the new code is the applicable cancer 

risk model for the old code
Conversion to ICD-10

 NCHS and CMS has issued a General Equivalency Mapping (GEM) 

 For every ICD-10-CM code, the GEM provides an equivalent ICD-9-CM 

code

 A flag is also included to indicate if it is an exact match or an approximate 

match

 DOL has been coding cancers under the ICD-10-CM system and using the 

GEM to also include an ICD-9-CM code for NIOSH

 NCHS and CMS indicated the 2018 GEM will be the last GEM they issue
 ORAU-RPRT-0098 provides the decision logic used to determine the 

applicable ICD-9-CM code for every ICD-10-CM code

 This logic concentrated on those codes flagged as approximate matches in 

the GEM

 Codes flagged as an approximate match were reviewed

Conversion to ICD-10 (continued-1)
Conversion to ICD-10 (continued-2)

 Many approximate matches resulted from ICD-10 codes being more 

specific

 Example:

– ICD-9 162.5 = lower lobe lung

– ICD-10 C34.30 = lower lobe unspecified lung

– ICD-10 C34.31 = lower lobe right lung

– ICD-10 C34.32 = lower lobe left lung

 162.5 was an approximate match because it matched more than one ICD10 code
Conversion to ICD-10 (continued-3)

 ORAUT-OTIB-0005 uses the lung for the internal organ, external organ and 

cancer risk model regardless of which side or lobe

 Therefore, ICD-9 code 162.5 is considered a match for each of the ICD-10 

codes and the organs and model from 162.5 is used for C34.30, C34.31 

and C34.32

 Decisions surrounding most other approximate flags are specifically 

included in ORAUT-RPRT-0098
Conversion to ICD-10 (continued-4)

 Review of approximate codes considered only DCAS use of the codes. 

 Information that may be useful for medical purposes was not considered 

for this exercise

 If organs and models were the same, it was considered a match
Secondary Cancers

 IREP technical documentation created a list of likely primary cancers for every 

secondary cancer

 This list was included in the initial 42 CFR pt. 81

 The list is used in cases of no known primary cancer. The probability of 

causation is determined for each of the likely primary cancers and the highest 

one used for the case
 Using the GEM list as clarified from ORAUT-RPRT-0098, the existing list was 

converted to ICD-10-CM codes

 The 42 CFR pt. 81 revision includes the new list with ICD-10-CM codes

Secondary Cancers (continued)