The Illicit Drug Reporting System is an annual, national project designed to monitor data associated with the use of heroin, cocaine, methamphetamine and cannabis, in order that this information could act as an early warning indicator of the availability and use of these drugs. Each year, in each capital city, people who regularly inject drugs are interviewed face to face about the drugs they use and their health. To complement and interpret this information, data relating to drug use such as needle and syringe program, health and law enforcement data are also examined.