# Presentation: 108855

## Revision trial of ICD-10 Ch XX on external causes of injury 

- Martti Virtanen, Kristina Bränd Persson
- WHO Collaborating Centre for the Family of International Classifications in the Nordic Countries, Uppsala, Sweden

## ICD revision process and relation of ICD to other classifications in health information systems

- The external causes classification constitutes a part of ICD but should also work quite independently
- How to collect detailed information with ability to aggregate to ICD-level
- Need for double coding must be avoided
- Terminology for ICD is included in ICECI and NCECI and the area is **not covered by SNOMED**

## External causes in mortality statistics

- WHO database on mortality
- about 1/3 of all deaths are reported to WHO
- Approx. 7% of deaths are coded by Chapter XX
- Within transport accidents 45% of codes are "unspecified"
- 13 out of 70 countries do not use the 4th character of ICD-10
- Approx. 400 ICD-10 codes are never used.

## Multiaxial system may cause problems for mortality statistics in continuity

- ICD-10
- For Mechanism and Intent a partial multiaxiality exists in ICD-10
- Several axes are implicit in Ch. XX, which allows for recoding of data
- ICD-11
- A practical solution is needed; a multiaxial classification can be used to create a flat list/compination of flat lists for mortality.
- The needs and corresponding structure should be made clear before codes are considered

## ICECI relation to ICD-10

- Documentation for v1.2 includes overview of ICECI in relation to ICD
- Mapping of modules for Mechanism and Intent according to ICECI is also shown
- In Ch. XIX the classes/terms is a mix of injuries and external causes
- In analysis of ICECI vs. ICD one should use the matrix and analyse the terms/concepts.
- Some ICECI terms differ and some are the same as in ICD but they should all be compatible with ICD (Chapter XIX, XX and V (drugs)).

## ICECI relation to ICD-10

- Ch. XX is a separate axis of ICD
- Problem in differentiation of Ch. V and intoxications - intoxication can be caused by psychiatric illness
- The design of core modules in ICECI was based on existing structure of Ch XX
- a separation of mechanism and intent link to the mortality matrix was made in cooperation with ICE
- a minimal coding bridge to ICD-9/10 from ICECI exists but a more robust bridge is needed
- The problem in making a flat projection is that the structure in ICD-10 is not logical
- logical structure can be created from the multiaxial approach

## Problems of ICD-10

- Instructions on Ch. XX use must be improved (inclusions, exclusions, coding instructions).
- Distinction between "undetermined intent" and "intent unspecified"
- Some intermediate level information should be permitted
- An algorithm for the selection of underlying cause code is needed

## Necessary modifications in ICD-11

- True axis/axes need to be developed
- Model 1 – ICD-10 model
- The code structure will include an axiality
- All valid codes are listed
- External cause information is compressed to one code
- Number of codes is high
- Restgroups with complex definitions need to cover all possibilities
- Model 2 – ICECI/NCECI modified
- Each axis of ICECI/NCECI is assigned own area of ICD-codes
- Complete description demands several external cause codes
- Restgroups are needed for each axis
- Number of combinations is almost unlimited
- Model 3 - Combined model
- Place, activity, intent as separate axis/axes i.e. own area(s) of ICD-codes
- Other axis combined to one list
- Number of coded need for external cause case limited to 1-3

## Loppu