Objectives. There is a recognised opportunity for more systematic and timely triangulation of existing data to rapidly assess and identify emerging illicit drug trends in Australia. The overarching aim of this scoping study was to determine the feasibility of establishing an Australian early warning system (EWS). The objectives were to:
1. Identify existing data sources routinely collected and collated; and
2. Identify and describe the data sources feasible for inclusion in an EWS.
Given indications of feasibility, the following objectives also applied to those data sources that met feasibility criteria:
3. Describe coverage across drugs and outcomes of interest;
4. Identify and describe other data sources (not yet collated) for inclusion to address gaps in coverage;
5. Identify and describe analytic and triangulation approaches and mode of availability; and
6. Develop a proposal for a pilot study of an EWS.

Methods. In this scoping study, we systematically reviewed multiple sources to identify existing routine data collections. We utilised information from online and from direct communication with data custodians to assess each data source against pre-specified feasibility criteria. We evaluated the data sources against feasibility criteria to determine whether they provided data on key outcomes and drugs of interest, and we consulted with an Advisory Committee and with key figures involved in international EWS regarding features of an EWS.

Results and conclusions. Key results and conclusions from this scoping study comprise the following.

1. There is an array of existing data sources on illicit drugs in Australia. There are currently 286 routinely collected and collated data sources measuring illicit drug use, harms, and/or market features in Australia.
2. Approximately one-quarter of these are feasible for inclusion in an EWS. A total of 76 sources met feasibility criteria for possible inclusion, with 53 sources pending feasibility on formal application for data access. There were a number of data sources meeting feasibility criteria in each jurisdiction, but only five data sources meeting criteria at the national level.
3. An Australian EWS is feasible at the jurisdictional level. A national profile of illicit drug use trends could be built bottom-up by establishing a jurisdictional-level EWS. State/territory custodians and stakeholders were supportive of establishing an EWS and noted existing informal information-sharing networks regarding illicit drug trends. Appropriate resourcing of data access, as well as ethical and organisational approval for data access, would be required for effective implementation.
4. Data sources that met feasibility criteria offer coverage of key outcomes and drugs of interest but there are gaps. The data sources cover most key outcomes and drugs of interest, with the exception of trends related to market features (e.g., illicit price, availability) and novel psychoactive substances.
5. Other data sources (namely online sources) could easily address these gaps. Online data sources comprise an easily accessible, relatively inexpensive, prolific (and relatively untapped) source of information which can complement traditional routine data collections. They are particularly important to monitoring illicit markets and novel psychoactive substances given availability of online drug marketplaces.
6. Data analysis/triangulation is feasible and online access to outputs has benefits. Quantitative analysis and triangulation would facilitate systematic and transparent detection of trends, and an online mode of availability could facilitate stakeholder engagement and allow for restricted access to outputs.
7. A pilot EWS in two jurisdictions is a suitable next step. Features of two jurisdictions (New South Wales and Queensland) are highlighted as indicative of particular preparedness for a pilot, with planned subsequent expansion to other jurisdictions. Implementation and evaluation over two years is proposed (with outputs within 6 months), and stakeholder involvement and appropriate resourcing flagged as key considerations.