Background The International Classification of Diseases (ICD) is the most widely used classification of injuries and their external causes, particularly in vital registers of deaths and systems to report on cases admitted to hospitals. The ICD has been revised 10 times, most recently in the late 1980s. The World Health Organisation (WHO) is conducting the 11^th revision.

Description of the problem Potential reasons to revise the classification include: the emergence of new knowledge; changing priorities and conceptualization of injuries and external causes; and matters unresolved in earlier revisions. National clinical modifications of earlier revisions (ICD-9 and ICD-10) have developed numerous, useful but sometimes non-comparable extensions to the international version. Dissatisfaction with aspects of the ICD external causes chapter prompted development of the International Classification of External Causes of Injuries (ICECI) and the revision provides an opportunity to integrate the ICECI with a new edition of the ICD.

Results In the first phase of the revision, advice was provided to the WHO on proposed changes, largely by Topic Advisory Groups, one of which has focused on the injury and external causes chapters. Also, the ICD was converted from a manually-curated list to a formal database of numerous potentially codeable entities, from which well-specified versions of ICD-11 (called ‘linearizations’) can be derived for particular purposes. In the second phase of revision, linearizations are being developed, with highest priority being given to the Joint Linearization for Mortality and Morbidity Statistics (JLMMS). A special linearization based on ICECI is envisaged.

Conclusions The form and content of the JLMMS are still in flux, but are expected to be in largely final draft by mid-2016. Injury researchers need to be aware of the forthcoming changes to the ICD, which will impact on injury statistics worldwide.