Quantifying the social and economic costs of cannabis and opioid use in Australia

NDRI collaborated with leading experts from the South Australian Centre for Economic Studies, the National Drug and Alcohol Research Centre (NDARC), the National Centre for Education and Training on Addiction (NCETA), the Centre for Youth Substance Abuse Research (CYSAR), NSW Bureau of Crime Statistics and Research and Curtin University to investigate the social costs of cannabis use and the misuse of opioids.

The social costs of alcohol and other drug use is of growing interest, especially in relation to the harms to other people, which have until recently been excluded from some cost of illness (COI) studies. COI studies identify and evaluate in monetary terms the total harms and other costs of a disease or condition to society and are primarily used to inform policy, encourage debate and support advocacy. This project will evaluate the harms arising from two of the most prevalent illicit drugs used in Australia – cannabis and, given concerns about the increased rate of deaths and hospitalisations due to opioids including the misuse of prescription opioids, from heroin and other opioids.

Cannabis is the most widely used illicit drug in Australia, with 34.8% of people reporting lifetime use and 10.4% use in the last year: a figure that has remained relatively stable for the last decade. Notably, cannabis is the only illicit drug where recent use (last 12 months) remains prevalent into late middle age, with 15% of those 50-59 year olds reporting its use. A report by Moore (2007) found that the use of cannabis cost $3.1 billion in 2004. An important element of updating this estimate will be attempting to identify information on extended periods of exposure and also the potential that harms have increased with higher potency forms of cannabis.

Since 2000, there have been major shifts in the use of heroin and opioid drugs in Australia. At the peak of the heroin crisis there were 1116 accidental deaths in 1999 with the majority attributed to heroin. By 2011, 70% of the 617 deaths were due to other opioids, with similar transitions reported in other countries. While Moore (2007) reported the social cost of opiates at $4.6 billion in 2004 – not dramatically different to the total cost arising from cannabis use - the cost on a ‘per user’ basis was dramatically higher at $30,633 versus $1,631. The prevalence of heroin use has remained relatively stable over the period since 2000 (at 0.1 - 0.2%): the questions on misuse of pharmaceuticals in the NDSHS have changed in recent editions so extended data are not available on this variable. Currently, 3.6% report recent use of pain-killers/analgesics and opioids (excluding over the counter products). One of the challenges for the costing exercise will be to obtain recent data of the use of these different classes of opioids and in evaluating the harms arising from their use. The analysis will seek to exclude any harms or adverse events arising from opioids when used as prescribed.

Both the opioid and cannabis reports are now publically available.