There are three mapping tables for mapping between ICD-10-AM first edition and second edition. Two files relate to forward mapping (converting ICD-10-AM first edition codes into ICD-10-AM second edition codes), and one file is for backward mapping (converting ICD-10-AM second edition codes into ICD-10-AM first edition codes).
The mapping tables include:
- diagnosis codes
- procedure/operation codes
- injury codes
- external cause codes
- morphology codes
- other health factors (previously known as V-codes).
These code tables do not include any punctuation in the code values (but punctuation is included in the NCCH coding books and in the encoder software).
The morphology codes sent to the Ministry of Health do not include the ‘M’ prefix that is used in Australia and may be included in the 3M encoder software. In addition, morphology codes should not include a fifth digit. This information is gathered by the Ministry of Health from labs and not from hospital discharge records.
Backward mapping file
This file is called codes_back_conversion.xls
The file has 20,731 rows, and contains the following fields:
- conversion_type
- cc_from
- code_from
- cc_to
- code_to
- change.
Conversion_type
This is the same value for all the rows in this file. The value is 1110, where 11 is the value of Clinical Coding System ID for ICD-10-AM second edition, and 10 is the value of Clinical Coding System ID for ICD-10-AM first edition. The code 1110 indicates that this mapping conversion changes code values from 11 to 10 (ie, ICD-10-AM second edition to ICD-10-AM first edition).
Cc_from
This field shows the value of the clinical code table type code associated with each mapped code. The values in this field are:
- A = diseases/diagnoses
- B = injury codes
- E = External cause codes
- O = procedure/operation codes
- M = morphology codes
- V = other health factors.
This field can be used if you only want a subset of the mapping codes – eg, to map only procedures/operations choose any rows with an O in the cc_from field.
Code_from
This is the ICD-10-AM second edition code value.
Cc_to
This field shows the value of the clinical code table type in ICD-10-AM first edition. The same range of code values are used in this field as are in the cc_from field.
Code _to
This is the ICD-10-AM first edition mapped code value.
Change
The values in this field are Y (yes) and N (no).
N (no) means that the ICD-10-AM second edition code maps to the same value in ICD-10-AM first edition and the mapped code value is used in the same way in both classifications.
Many of the codes in ICD-10-AM second edition are the same as in ICD-10-AM first edition. However, some of the codes were deleted from ICD-10-AM first edition when the second edition was developed, but the same code value was re-used in second edition with a different meaning.
Y (yes) means either that the ICD-10-AM second edition code maps to a different ICD-10-AM first edition code, or that the second edition code maps to the same first edition code but the first edition code has a different meaning.
Forward mapping files
There are two forward mapping files – one is for External cause codes (ie, codes with a clinical code table type of E) and one is for all of the other codes (includes diagnosis, procedure/operation, morphology and health factors [V-codes]).
The two forward mapping files are called ecodes_forwd.xls and codes_forw_conversion.xls.
In ICD-10-AM second edition, E-codes (external cause codes) are no longer reported as one code – place and activity, which were the 4th and 5th digits of the first edition codes are reported as separate codes. There is therefore a one-to-many mapping between ICD-10-AM first edition external cause codes (E-codes) and ICD-10-AM second edition external cause codes. The place codes and acitivity codes have a clinical code table type of E.
One first edition E-code code can map to either:
- one second edition E-code code, or
- one second edition E-code code and a place code, or
- one second edition E-code code and a place code and an activity code.
Ecodes_forwd.xls
This file has 21,067 rows, and contains the following fields:
- clincd_v1
- clincd_v2
- place
- activity.
In this file, 20,707 mapped codes have an activity code and a place code, 341 mapped codes have a place but no activity code, and 19 mapped codes have no place and no activity code.
Clincd_v1
The clinical code value in ICD-10-AM first edition.
Clincd_v2
The mapped clinical code value in ICD-10-AM second edition.
Place
The ICD-10-AM second edition code for the place where the person was when they were injured.
Activity
The ICD-10-AM second edition code for the activity the person was doing when they were injured.
Codes_forw_conversion.xls
This file has 19,635 rows, and contains the following fields:
- conversion_type
- cc_from
- code_from
- cc_to
- code_to
- change.
Conversion_type
This is the same value for all the rows in this file. The value is 1011, where 10 is the value of Clinical Coding System ID for ICD-10-AM first edition, and 11 is the value of Clinical Coding System ID for ICD-10-AM second edition. The code 1011 indicates that this mapping conversion changes code values from 10 to 11 (ie, ICD-10-AM first edition to ICD-10-AM second edition).
Cc_from
This field shows the value of the clinical code table type code associated with each code. The values in this field are:
- A = diseases/diagnoses
- B = injury codes
- O = procedure/operation codes
- M = morphology codes
- V = other health factors.
(There are no codes with a clinical code table type of E – external cause codes in this mapping file. To forward map external cause codes use the file ecodes_forwd.xls).
The cc_from field can be used if you only want a subset of the mapping codes; eg, to map only procedures/operations choose any rows with an O in the cc_from field.
Code_from
This is the ICD-10-AM first edition code value.
Cc_to
This field shows the value of the clinical code table type in ICD-10-AM second edition. The same range of code values are used in this field as are in the cc_from field.
Code_to
This is the ICD-10-AM second edition mapped code value.
Change
The values in this field are Y (yes) and N (no).
N (no) means that the ICD-10-AM first edition code maps to the same value in ICD-10-AM second edition and the mapped code value is used in the same way in both classifications.
Many of the codes in ICD-10-AM first edition are the same as in ICD-10-AM second edition. However, some of the codes were deleted from ICD-10-AM first edition when the second edition was developed but the same code value was re-used in second edition with a different meaning.
Y (yes) means either that the ICD-10-AM first edition code maps to a different ICD-10-AM second edition code, or that the first edition code maps to the same second edition code but the second edition code has a different meaning.