Overview

• Some people with substance use disorders, particularly people who inject drugs and people with cocaine1 , amphetamine2 , or opioid dependence3 , are at elevated risk of mortality.These elevated risks tend to be concentrated across a few key domains. Some of those are related to the manner in which drugs are taken (e.g. contraction of blood borne viral infections such as HIV through sharing of injection equipment); others may be related to the effects of drug and alcohol use (e.g. liver disease) and others still as relatively direct consequences of acute drug intoxication (e.g. accidental drug overdose).
• Classifying deaths into appropriate categories is not a straightforward task. Multiple iterations of the World Health Organization’s (WHO) International Classification of Diseases exist, each of which defines deaths slightly differently. Some codes are not readily interpretable as belonging to a distinct grouping. Hundreds of codes exist, so the volume of categories may present challenges.
• This bulletin provides an overview of some key references that provide guidance on classifying major causes of death that occur among people who use illicit drugs. It is intended to make categorization of deaths among illicit drug users an easier process, and perhaps one that is undertaken more consistently across studies.
• It provides groupings for both the International Classification of Diseases Version 9 (ICD-9) and Version 10 (ICD-10). The comparable codes in each are listed alongside each other. There may be differences in the deaths captured due to the version change, and this should be noted when analysing data across time.
• The source of each of these groupings is provided alongside each for ease of reference.
• Feedback on these groupings or suggestions for further groupings are welcomed.
• This is an update of a technical report from 2009.