ICD codes used to identify ‘substance misuse’
| Substance misuse hospital admissions were identified using the following ICD-9 codes for the period 1981 to March 1996: | Drug dependence codes (304.1–304.9 and 305.2–305.9) |
| Overdose codes for heroin and methadone* (E850.0 and E850.1, respectively) | |
| Thereafter, up to the end of 2001, people given the following ICD-10 codes were identified as being substance misuse related: | Mental and behavioural disorders due to psychoactive substance use (F11–F16 and F18–F19) |
| Overdose (heroin, methadone, cocaine or cannabis) (T40.1, T40.3, T40.5 and T40.7, respectively) |
↵* International Classification of Diseases (ICD) version 9 does not have a code for cocaine-related overdose.