Data quality

National Drug Strategy Household Survey, AIHW

The National Drug Strategy Household Survey (NDSHS) collects information on alcohol and tobacco consumption, and illicit drug use among the general population in Australia. It also surveys people’s attitudes and perceptions relating to tobacco, alcohol and other drug use. The survey has been conducted every 2 to 3 years since 1985. The AIHW has been collating and reporting on these surveys since 1998. Key quality issues to consider for the collection include:

  • Reported findings are based on self-reported data and are not empirically verified by blood tests or other screening measures.
  • It is known from past studies of alcohol and tobacco consumption that respondents tend to underestimate actual consumption levels.
  • Estimates of illicit drug use and related behaviours are also likely to be underestimates of actual use.
  • The exclusion of persons from non-private dwellings, institutional settings, homeless people and the difficulty in reaching marginalised persons are likely to have affected estimates.
  • The response rate for the 2016 survey was 51.1%. Given the nature of the topics in this survey, some non-response bias is expected, but this bias has not been measured.
  • Both sampling and non-sampling errors should be considered when interpreting results.
  • The 2016 survey used a multi-mode completion methodology—respondents could choose to complete the survey via a paper form, an online form or via a telephone interview. This was the first time an online form has been used in the survey series. Changes in mode may have some impact on responses, and users should exercise some degree of caution when comparing data over time

The full data quality statement for the NDSHS 2016.

Alcohol and other Drug Treatment Services National Minimum Dataset, AIHW

The Alcohol and Other Drug Treatment Services National Minimum Dataset (AODTS NMDS) is based on closed episodes of treatment provided to clients by alcohol and other drug treatment services. All in-scope service agencies are publicly funded through state, territory or Australian government programs. Key quality issues to consider for the collection include:

  • Funding programs cannot be differentiated—services are categorised according to sector, with government-funded and operated services reported as public services and those operated by non-government organisations reported as private services.
  • National data are affected by variations in service structures and collection practices between states and territories; these should be considered when making comparisons between jurisdictions.
  • The AODTS NMDS reports both main and additional treatment types. Victoria and Western Australia do not differentiate between main and other treatment types. This needs to be taken into account when comparing episodes from these states with other states and territories.

The full data quality statement for the AODTS NMDS 2016–17.

National Opioid Pharmacotherapy Statistical Annual Data Collection, AIHW

The main purpose of the NOPSAD collection is to aggregate standardised jurisdictional data on the number of clients accessing pharmacotherapy for the treatment of opioid dependence, the number of prescribers participating in the delivery of pharmacotherapy treatment, and quantitative information about the prescribing sector. Key quality issues to consider for the collection include:

  • Each state and territory use different methods to collect data about the pharmacotherapy used to treat those with opioid dependence. These methods are driven by differences between the states and territories in relation to legislation, information technology systems and resources. These differences may result in discrepancies and need to be considered when comparing data across jurisdictions.
  • New South Wales is unable to differentiate between clients prescribed buprenorphine and buprenorphine-naloxone.
  • Indigenous status of client is reported as a total by Victoria, i.e. a breakdown of Indigenous status by individual pharmacotherapy drug type is not available. Indigenous status of client is not reported by Western Australia.
  • In Western Australia, the number of clients receiving pharmacotherapy treatment is reported through the month of June (rather than on a snapshot day), likely resulting in an over-representation of clients in Western Australia.
  • In Tasmania, the number of clients receiving treatment in June is counted. If a client changes dosing point sites during the month they are only counted once and the dosing point that administered the greater number of doses is attributed the activity.
  • Unit record data were provided by all jurisdictions except Victoria and Queensland.

The full data quality statement for the 2017 NOPSAD.

National Aboriginal and Torres Strait Islander Social Survey 2014–15, ABS

The 2014–15 NATSISS was conducted throughout Australia, including remote areas, from September 2014 to June 2015.

  • The scope of the survey is all Aboriginal and Torres Strait Islander people who were usual residents of private dwellings in Australia. Private dwellings are houses, flats, home units and any other structures used as private places of residence at the time of the survey. People usually resident in non-private dwellings, such as hotels, motels, hostels, hospitals, nursing homes, and short-stay caravan parks were not in scope. Usual residents are those who usually live in a particular dwelling and regard it as their own or main home.
  • After screening and sample loss (due to households with no residents in scope for the survey or where dwellings proved to be vacant, under construction or derelict) 8,235 dwellings were approached for an interview. Of these eligible dwellings, 80% responded fully (or adequately) which yielded a total sample from the survey of 6,611 dwellings. An adequately responding household was defined as a household where at least one of the persons selected for the survey completed their interview.

The full data quality statement for the 2014–15 NATSISS.

Australian Aboriginal and Torres Strait Islander Health Survey 2012–13, ABS

The 2012-13 AATSIHS was conducted throughout Australia in remote and non-remote areas from April 2012 to February 2013. The 2012-13 AATSIHS collected information on a range of demographics from over 9,000 Aboriginal and Torres Strait Islander people of all ages.

The scope of the survey was all Aboriginal and Torres Strait Islander people who were usual residents of private dwellings in Australia. Private dwellings are houses, flats, home units and any other structures used as private places of residence at the time of the survey. People usually resident in non-private dwellings, such as hotels, motels, hostels, hospitals, nursing homes, and short-stay caravan parks were not in scope. Usual residents are those who usually live in a particular dwelling and regard it as their own or main home.

The 2012–13 AATSIHS was designed to produce reliable estimates at the national level and for each state and territory. For selected states and territories, that is New South Wales, Queensland, Western Australia and the Northern Territory, the sample for children aged 0–14 years and persons aged 15 years and over was allocated to produce estimates that have a relative standard error (RSE) of no greater than 25% for characteristics that at least 5% of these populations would possess.

The 2012–13 AATSIHS contains information from the Australian Aboriginal and Torres Strait Islander Health Survey (AATSIHS) core sample of around 12,900 people (a combined data file of both the National Aboriginal and Torres Strait Islander Health Survey (NATSIHS) and the National Aboriginal and Torres Strait Islander Nutrition and Physical Activity Survey (NATSINPAS) for people aged 2 years and over).

Further information about the AATHIHS.

National Aboriginal and Torres Strait Islander Health Survey 2004–05, ABS

The 2004–05 National Aboriginal and Torres Strait Islander Health Survey (NATSIHS) is the largest health survey of Indigenous Australians conducted by the Australian Bureau of Statistics (ABS). The sample size was 10,439 persons (or about one in 45 of the total Indigenous population), considerably larger than the supplementary Indigenous samples in the 1995 and 2001 National Health Surveys (NHS).

This survey, which was conducted in remote and non-remote areas throughout Australia, was designed to collect a range of information from Indigenous Australians about health related issues, including health status, risk factors and actions, and socioeconomic circumstances.

The sample covered usual residents of private dwellings only. Private dwellings are houses, flats, home units and any other structures used as private places of residence at the time of the survey. Usual residents are those people who usually live in a particular dwelling and regard it as their own or main home. Usual residents of 'special' dwellings such as hotels, motels, hostels and hospitals were not included in the survey. Visitors to private dwellings were also excluded from the survey as well as persons whose usual place of residence was outside Australia.

Further information about the NATSIHS 2004–05.

Causes of Death, Australia ABS

Statistics presented in Causes of Death, Australia, 2016 and 2017 (cat. no. 3303.0) are sourced from death registrations administered by the various state and territory Registrars of Births, Deaths and Marriages. It is a legal requirement of each state and territory that all deaths are registered. In addition, the ABS supplements this data with information from the National Coronal Information System (NCIS) for those deaths certified by a coroner.

Deaths are considered “drug induced” if directly attributable to drug use (e.g. drug overdose), and “drug related” where drugs played a contributory factor (e.g. traffic accidents ).

In Australia, acute drug overdose deaths are referred to a coroner and subject to forensic pathology and toxicology. Autopsy and toxicology reports provide detailed drug information including the identification of specific drugs in the system, approximate levels of drugs in the system and the relatedness of drugs to the death. The ABS accesses this information via the NCIS and applies codes from the International Classification of Diseases, 10th Revision, to the medical text for tabulation into statistical output.

Further information on Cause of deaths, Australia.

Illicit Drugs Reporting System, NDARC

The Illicit Drug Reporting System (IDRS) is a national illicit drug monitoring system intended to identify emerging trends of local and national concern in illicit drug markets. The IDRS consists of annual interviews across all Australian jurisdictions with people who inject drugs (PWID), as well as analysis and examination of indicator data sources related to illicit drugs.

  • 910 participants were recruited to the 2018 IDRS survey. The sample sizes reflect predetermined quotas.
  • Although the IDRS is well able to monitor trends in established drug markets and document the emergence of drug use among people who regularly inject drugs, it cannot provide information on drug use and harms among all groups of people who use drugs.
  • The IDRS sample is a sentinel group that provides information on patterns of drug use and market trends.

Further information about the IDRS.

Ecstasy and related Drugs Reporting System, NDARC

The Ecstasy and Related Drugs Reporting System (EDRS) is a national monitoring system for ecstasy and related drugs that is intended to identify emerging trends of local and national interest in the markets for these drugs. The EDRS is based on the IDRS methodology and consists of three components: interviews with regular ecstasy and psychostimulant users; interviews with key experts, professionals who have regular contact with regular recreational users through their work; and analysis and examination of indicator data sources related to ecstasy and other related drugs. The EDRS monitors the price, purity, availability and patterns of use of ecstasy, methamphetamine, cocaine, ketamine, GHB, MDA and LSD.

  • 799 participants were recruited to the 2018 EDRS survey. The sample sizes reflect predetermined quotas.
  • The EDRS sample is a sentinel group that provides information on patterns of drug use and market trends.

Further information about the EDRS.

National Wastewater Drug Monitoring Program, ACIC

The method underlying wastewater based monitoring of drug use in a given population is based on the principle that any given compound that is consumed (irrespective of whether it is swallowed, inhaled/smoked or injected) will subsequently be excreted (either in the chemical form it is consumed and/or in a chemically modified form that is referred to as a metabolite). The excreted compound or metabolite will eventually arrive in the sewer system.

Collectively, waste products in the sewer system arrive at a wastewater treatment plant (WWTP) where wastewater samples are collected over a defined sampling period. Measuring the amount of target compound in the wastewater stream allows for a back-calculation factor to be applied to determine the amount of drug that was used over the collection period. The method is non-invasive and is done on a population-scale level, so individuals are not targeted and privacy is respected.

Wastewater consists of highly complex mixtures which derive from toilets, bathrooms, kitchen and laundry appliances, as well as all other domestic, industrial or commercial plumbed structures. To obtain an estimate of drug use, representative samples are collected over a given period (typically 24 hours) using autosamplers that collect time or flow proportional samples. Wastewater treatment plant operators provide assistance with collecting the samples from the influent autosampler (where the wastewater enters the treatment plants). Pertinent information on the volume of wastewater entering the WWTP (flow volume) that is associated with a given sample is also collected by local operators. It should be noted that rain events may, for example, cause an increase in the volume of wastewater that enters a treatment plant but providing that the flow volume is available for each sampling period, this will not affect the overall estimate of the amount of drugs that has been used by the population that contributed to this wastewater.

The measurement of cannabis consumption was included for the first time in the August 2018 collection. It should be noted that the detection of the main compound in cannabis, tetrahydrocannabinol (THC), is affected by surface adsorption. Sewer design and collection method may influence the levels detected and samples must be preserved to avoid degradation.

Cannabis was not included in the comparison of the highest consumed drugs as there is variation in dose sizes and using an averaged dose was not deemed appropriate for the purposes of the study.

Illicit Drug Data Report, ACIC

This report brings together illicit drug data from a variety of sources including law enforcement, forensic services, health and academia. Data used to inform the Illicit Drug Data Report is provided by all Australian state and territory police agencies, the Australian Federal Police, the Department of Home Affairs, Australian Border Force, the Australian Institute of Criminology and forensic laboratories. Data collected and presented in the report includes arrest, detection seizure, purity, profiling and price data. The statistics and analysis in the report are primarily used in to inform understanding of the Australian illicit drug market and the development of drug supply and harm reduction strategies.

Drug Use Monitoring in Australia Program, AIC

The Drug Use Monitoring in Australia (DUMA) program is an ongoing illicit drug use monitoring program that captures information on approximately 2 200 police detainees per year, across five locations throughout Australia. There are two core components: a self-report survey and voluntary provision of a urine sample which is subjected to urinalysis at an independent laboratory to detect the presence of licit and illicit drugs. The self-report survey captures a range of criminal justice, demographic, drug use, drug market participation and offending information. Urinalysis serves as an important objective method for corroborating self-reported drug use. Not all detainees who respond to the self-report survey agree to provide a urine sample when requested, although the urine compliance rate is high.