National Aboriginal and Torres Strait Islander Health Survey methodology

The 2018–19 National Aboriginal and Torres Strait Islander Health Survey (NATSIHS) sample was designed to provide reliable estimates for the Aboriginal and Torres Strait Islander population for the whole of Australia, at state/territory level and for non-remote and remote areas.

The sample design had an expected number of 11,700 fully responding persons. The final processing file compromised 10,579 fully responding persons, the calculation of which is explained below.

A total of 9,284 private dwellings were selected in the sample. These were identified by screening households in non-community areas or through selections of discrete Indigenous communities. The sample was then reduced to 8,707 households after excluding those unable to be contacted after screening

Of the 8,707 households in the final sample, 6,388 (73.4%) were fully or adequately responding households. These are households where at least one person selected to complete the survey had either completed it fully or to a point where their data could still be used.

From the 6,388 fully or adequately responding households, there were 10,579 people included in the sample.

Persons in the sample were then weighted to population benchmarks to reflect the size, age structure and geographical distribution of the total population. For more information about the population benchmarks, see Explanatory notes section.

In the 2018–19 National Aboriginal and Torres Strait Islander Health Survey (NATSIHS), physical measurements of height, weight and waist circumference were collected from respondents aged two years and over, and was a voluntary component of the survey. Women who advised that they were pregnant were not measured. Voluntary blood pressure measurements were also collected from respondents aged 18 years and over. Persons with a high Body Mass Index (BMI) or blood pressure are at risk of developing chronic disease. BMI is a simple index of weight-for-height, which defines whether a person is underweight, normal weight, overweight or obese – see Appendix - Assessing health risk factors.

Physical measurements had a relatively high rate of non-response due to their voluntary and sensitive nature. To correct for the high rate of non-response, imputation of values for those that did not have measurements collected was used to achieve estimates of physical measurements for the whole population.

In addition to the voluntary measured items, respondents in the 2018–19 NATSIHS were also asked to self-report their height and weight measurements. Of those whose BMI was not measured, 55.8% of adults and 34.3% of children provided both self-reported height and weight measurements. This provided valuable information about the height and weight that was used in the imputation for people with missing values.

In the 2018–19 NATSIHS and both the 2014–15 National Aboriginal and Torres Strait Islander Social Survey (NATSISS) and 2017–18 National Health Surveys (NHS), missing values were imputed using the 'hot decking' imputation method. In this method, a record with a missing response (the 'recipient') receives the response of another similar record (the 'donor').

A number of characteristics (imputation variables) were used to match recipients to donors.

For adults they were:

• age group

• sex

• part of state (capital city and balance of state)

• self-perceived body mass (underweight, acceptable, or overweight)

• level of exercise (sedentary, low, moderate or high)

• whether or not has high cholesterol (as a long-term health condition)

• self-reported BMI category (calculated from self-reported height and weight).
   

For example, a female recipient aged 35–39 years who lives in a capital city, has a self-reported BMI category of overweight (calculated using self-reported height and weight), has a self-perceived body mass of healthy, has high cholesterol and lives a sedentary lifestyle will match to a donor record who has the same profile (female, 35–39 years, self-reports as overweight, etc).

For BMI, 80.4% of imputed records used all seven imputation variables to match to a donor record. The remaining 19.6% could not be matched using all seven variables and were therefore matched using fewer variables. For example, 7.4% of imputed records were matched to donors using all imputation variables except part of state.

For children aged 2–14 years, the following variables were used:

• single year of age

• sex

• self-reported BMI

• part of state.
   

For those aged 15–17 years, the same imputation variables were used as for those aged 2–14 years, in addition to level of exercise and self-perceived body mass (only if a person answered for themselves). Cholesterol data was not collected for persons under 18 years of age and so could not be used as an imputation variable.

Single year of age was used in the imputation method for the 2018–19 NATSIHS, which differs from the 2017–18 NHS. The change was made for the 2018–19 NATSIHS as children's height and weight can change rapidly within a short period of time and, to avoid over or under estimating BMI, donors that were of the same age as the recipient were used. A similar change to the imputation method will be investigated for the next iteration of the NHS.

Physical measurement data (BMI, waist circumference and blood pressure) that includes imputed values are of suitable quality for comparisons with previous surveys; however, the Australian Bureau of Statistics (ABS) recommends using proportion comparisons only as imputation was not used on the physical measurement data in previous years.

The table below shows the impact of imputation on BMI estimates.

This appendix provides information about the questions used to measure mental health conditions, and the questions to measure social and emotional wellbeing.

A new set of questions on mental and behavioural conditions was introduced in 2018–19, which asked respondents aged two years and over whether they had any of the following:

• depression

• anxiety

• harmful use or dependence on alcohol or drugs

• behavioural or emotional problems, and/or

• other mental health conditions.
   

Development and testing of the questions was informed through advice from an expert advisory panel, comprising members from government and non-government agencies. The questions were tested in non-remote and remote areas of Australia.

The change to the collection of this data means the 2018–19 results are not comparable with the 2012–13 National Aboriginal and Torres Strait Islander Health Survey (NATSIHS), the 2014–15 National Aboriginal and Torres Strait Islander Social Survey (NATSISS), or the 2017–18 National Health Survey (NHS).

• In the 2012–13 NATSIHS and the 2014–15 NATSISS, information about mental or behavioural conditions was collected as part of a set of questions covering a wide range of long-term health conditions. Results for 2018–19 show a higher proportion of people reported having a mental or behavioural condition than in 2012–13 and 2014–15. This may be due to the greater prominence of mental health questions in 2018–19.

• The ordering and wording of the questions in 2018–19 differs from the 2017–18 NHS. In 2018–19 respondents were asked whether they had been diagnosed with any of the listed conditions by a health professional, followed by questions on whether those conditions were still current and whether they had lasted, or were expected to last, six months or more. In the NHS, respondents were asked about any mental health conditions they had, regardless of whether those conditions were diagnosed by a health professional, followed by questions on the duration of those conditions and whether they had been diagnosed by a health professional.

• A list of mental and behavioural conditions was presented to people on a prompt card and the 2018–19 list was shorter than the 2017–18 NHS list. This was done to ensure the conditions on the prompt card could be easily identified by people in both non-remote and remote areas.
   

Social and emotional wellbeing was measured using several short series of questions taken from existing health and wellbeing surveys. Respondents aged 18 years and over and present at the interview were asked these questions. These questions could not be answered by someone else on the respondent’s behalf.

• Two sets of questions asked about the frequency of specific feelings in the four weeks prior to interview to measure psychological distress and positive emotional states.

• People in non-remote areas were asked two additional sets of questions about levels of mastery (the sense of control over one’s life) and perceptions of social support.
   

The Kessler 5 (K5) score is a measure of non-specific psychological distress, derived from a modified version of the Kessler Psychological Distress Scale (K10). It uses five questions (instead of 10), and is designed for use in surveys of Aboriginal and Torres Strait Islander peoples. For more information see Information Paper: Use of the Kessler Psychological Distress Scale in ABS Health Surveys, Australia (cat. no. 4817.0.55.001).

The K5 (and K10) is not a diagnostic tool, but is used as an indicator of levels of psychological distress experienced recently.

• Respondents were asked questions about how often they had experienced negative emotional states in the previous four weeks by selecting one of five responses presented on a prompt card, ranging from ‘all of the time’ to ‘none of the time’.

• ‘Don’t know’ and refusal options were available and, if selected, an overall score was unable to be determined.

• Responses to the questions were combined to produce an overall score between five and 25.

• The scores were then grouped to describe the level of psychological distress as low/moderate (5–11) or high/very high (12–25).
   

The psychological distress results are comparable with the 2012–13 NATSIHS and the 2014–15 NATSISS. They are also comparable with the 2017–18 NHS, but there are some differences:

• the NHS uses the K10 instead of the K5

• two of the questions in the K10 are asked slightly differently in the K5 to ensure the questions are culturally relevant for Aboriginal and Torres Strait Islander people

• respondents were unable to select a response of ‘Don’t know’ in the NHS.
   

There were four positive wellbeing questions, taken from the mental health and vitality scales of the Short Form 36 Health Survey (SF–36).

• Respondents were asked questions about how often they had experienced positive emotional states in the previous four weeks by selecting one of five responses presented on a prompt card, ranging from ‘all of the time’ to ‘none of the time’.

• ‘Don’t know’ and refusal options were available.
   

The results from each of the four questions are comparable with the 2012–13 NATSIHS and the 2014–15 NATSISS.

The Pearlin Mastery Scale is a set of seven statements used to measure how much a person feels in control over life events and outcomes. Higher levels of mastery can lessen the impact of stress on a person’s physical and mental wellbeing.

• Respondents were asked to respond to each statement by selecting one of four responses presented on a prompt card, ranging from ‘strongly agree’ to ‘strongly disagree’.

• ‘Don’t know’ and refusal options were available and, if selected, an overall score was unable to be determined.

• Responses to the statements were combined to produce an overall score between seven and 28.

• The scores were then grouped to describe the level of mastery as low (7–19) or high (20–28).
   

The Pearlin Mastery overall score and results from the individual statements are not comparable with the 2012–13 NATSIHS due to response category changes.

A set of six statements from the Multidimensional Scale of Perceived Social Support (MSPSS) was used to measure a person’s perception of the social support they receive from family and friends.

• Respondents were asked to respond to each statement by selecting one of seven responses presented on a prompt card, ranging from ‘very strongly disagree’ to ‘very strongly agree’.

• ‘Don’t know’ and refusal options were available and, if selected, a score was unable to be determined.

• Responses to the statements were combined to produce a family score, a friends score and an overall score.

• The family, friends and overall scores were grouped to describe the level of perceived social support from each dimension as low (1–2.9), moderate (3–5) or high (5.1–7).
   

The MSPSS family, friends and overall scores and results from the individual statements are not comparable with the 2012–13 NATSIHS due to response category changes.

Several other questions were asked to determine:

• the impact of psychological distress on employment and other regular activities
• how often physical health problems had been the cause of psychological distress
• use of health and community services, such as doctors and counsellors, for mental health
• barriers to using health services for mental health.

This appendix provides information about the guidelines and measures used to assess some specific lifestyle and related factors that impact on health.

Alcohol consumption risk levels were assessed using the single occasion and lifetime risk guidelines from the National Health and Medical Research Council (NHMRC) 2009 Australian Guidelines to Reduce Health Risks from Drinking Alcohol.

• These two guidelines are for people aged 18 years and over and recommend a maximum number of standard drinks per day. A standard drink contains 12.5 millilitres (mLs) of alcohol.

• A separate guideline advises that, for people aged 15–17 years, the safest option is to delay the initiation of drinking alcohol for as long as possible. In this survey, people aged 15–17 years are assessed against the single occasion and lifetime risk guidelines to provide an estimate of the level of risk for this age group.
   

Alcohol consumption is likely to be under-reported. Some people who drank alcohol may not have reported it, and some may have reported it but understated the quantity consumed. The extent to which under-reporting has occurred is not able to be quantified.

The single occasion risk guideline advises healthy males and females to drink no more than four standard drinks on a single occasion to reduce the risk of alcohol-related injury arising from that occasion.

In this survey, a person was considered to have exceeded the single occasion risk guideline if they had consumed more than four standard drinks on at least one day in the last 12 months.

• This was assessed using a person’s response to questions about the number of times in the last 12 months they had consumed five or more standard drinks in one day.

• The number of standard drinks was as reported by the person. This is different to the lifetime risk guideline, where the number of standard drinks was derived from information about the number, type, brand, and serving size of drinks consumed.
   

The lifetime risk guideline advises healthy males and females to drink no more than two standard drinks per day to reduce the risk of harm from alcohol-related disease or injury over their lifetime.

In this survey, a person was considered to have exceeded the lifetime risk guideline if they had consumed more than two standard drinks per day on average in the last week. It was assumed the level of alcohol consumption in the last week was typical.

The average number of standard drinks per day was derived from information provided by the person about:

• the number, type, brand, and serving sizes of alcoholic drinks consumed on (up to a maximum of) the three most recent days alcohol was consumed in the week prior to interview, and

• the total number of days alcohol was consumed that week.
   

It was derived by:

• calculating the total amount of alcohol consumed (in mLs) for each drink type by multiplying the alcohol content (%) by the volume (mL), based on the type (e.g. light beer, red wine), brand and number of drinks reported on the maximum of three most recent days alcohol was consumed in the previous week

• summing the drink type results to derive the total alcohol consumption for the maximum of three most recent days alcohol was consumed

• dividing that result by the number of days on which alcohol consumption was reported (that is, by one, two or three) to derive average daily alcohol consumption for those days

• multiplying that daily average by the total number of days alcohol was consumed that week, and

• dividing the result by seven to arrive at the average number of standard drinks consumed per day.
   

Where the precise type and/or brand of the drink was not known, the following default alcohol content values were used:

• light beer — 2.7%

• mid-strength beer — 3.5%

• full-strength beer — 4.9%

• wine coolers — 3.5%

• low alcohol wines — 0.9%

• fortified wines — 17.8%

• white wine — 12.4%

• red wine — 13.3%

• sparkling wine/champagne — 13.3%

• spirits — 40.0%

• liqueurs — 20.0%

• pre-mixed spirits (e.g. UDL) — 5.0%

• alcoholic cider — 4.7%

• cocktails — 31.5%

• other alcoholic drinks — 27.4%.
   

Particular types or brands may contain more or less alcohol than this. However, the default values were considered sufficiently representative for the purposes of assessing lifetime risk and single occasion risk.

People who did not consume any alcohol in the week prior to interview were categorised as:

• last consumed more than one week to less than 12 months ago

• last consumed 12 months or more ago, or

• never consumed.
   

For a detailed explanation of the method used to measure alcohol consumption in ABS health surveys, see Alcohol Consumption in Australia: A Snapshot (cat. no. 4832.0.55.001).

People aged 18 years and over were asked to provide a blood pressure reading, voluntarily taken by the interviewer at the time of interview. Readings were categorised as:

• normal — less than 120/80 mmHg (millimetres of mercury)

• normal-high — from 120/80 to less than 140/90

• high — from 140/90 to less than 160/100

• very high — from 160/100 to less than 180/110

• severe — from 180/110.
   

People were placed in the highest of the categories that either the systolic or diastolic reading fell into.

A reading of 140/90 mmHg or higher does not necessarily indicate a person has hypertension. In this survey, hypertension is defined as a condition that has lasted, or which the respondent expects to last, for six months or more.

The reading also does not take into account whether a person might have had a high blood pressure reading if they were not managing it through the use of medication.

Body Mass Index (BMI) is a simple index of weight-for-height, commonly used for defining whether a person is underweight, normal weight, overweight or obese.

A BMI score is calculated using the formula weight (in kilograms) divided by the square of height (in metres). For example, a person who weighs 70 kilograms and whose height is 1.75 metres will have a BMI of 22.9 (70/(1.75m2) = 70/3.06 = 22.9).

There were two measures of BMI in this survey:

• self-reported (for people aged two years and over) — based on a person reporting their height and weight

• measured (for people aged two years and over) — based on a measure of the person’s height and weight, voluntarily taken by the interviewer at the time of interview.
   

Interviewers used digital scales to measure weight (maximum 200 kilograms) and a stadiometer to measure height (maximum 210 centimetres). Women who advised they were pregnant were not measured. For more information see Appendix - physical measurements.

People aged 18 years and over were classified as underweight, normal weight, overweight or obese based on their BMI score as recommended by the World Health Organization’s BMI Classification:

• underweight Class 3 — 15.99 or less

• underweight Class 2 — 16.00–16.99

• underweight Class 1 — 17.00–18.49

• normal range — 18.50–24.99

• overweight — 25.00–29.99

• obese Class 1 — 30.00–34.99

• obese Class 2 — 35.00–39.99

• obese Class 3 — 40.00 or more.
   

BMI categories for children aged 2–17 years were:

• underweight — Class 3, Class 2, and Class 1

• normal range

• overweight

• obese Class 1.
   

The BMI scores for each category take into account the age and sex of the child. For a detailed list of the cut-offs see Appendix 4 in the National Health Survey: Users’ Guide, 2017–18 (cat. no. 4363.0).

Breastfeeding of children aged three years and under was assessed using the National Health and Medical Research Council's 2012 Infant Feeding Guidelines. The guidelines recommend infants:

• be exclusively breastfed to around six months of age (the six month guideline)

• continue to be breastfed with appropriate complementary foods until at least 12 months of age (the 12 month guideline).
   

The six month guideline was considered to have been met if a child had been exclusively breastfed for at least six months. Children under the age of six months were excluded.

The 12 month guideline was considered to have been met if a child was exclusively breastfed for at least six months and then continued to be breastfed to 12 months of age. Children under the age of 12 months were excluded.

If unable to determine whether a child was exclusively breastfed for six months, or exclusively breastfed for six months then continued to be breastfed to 12 months of age, they were classified as not known.

For further information about collection methods and data quality see Explanatory notes section.

Fruit and vegetable consumption was assessed using the National Health and Medical Research Council (NHMRC) 2013 Australian Dietary Guidelines.

• The guidelines recommend a minimum number of serves of fruit and vegetables each day, depending on a person's age and sex.
• Several age recommendations include half servings. In this survey, only whole serves were collected, so half serves in the guidelines were rounded up to the nearest whole serve for the purpose of assessing whether a person met the relevant guideline.
   

Both males and females were considered to have met the guideline for fruit consumption if they usually consumed at least the following number of serves per day:

• one serve for those aged 2–3 years
• two serves for those aged four years and over.
   

One serve is approximately 150 grams of fresh fruit or 30 grams of dried fruit.

Children were considered to have met the guideline for vegetable consumption if they consumed at least the following number of serves per day:

• three serves for those aged 2–3 years
• five serves for those aged 4–8 years
• five serves for those aged 9–11 years
• six serves for boys aged 12–17 years
• five serves for girls aged 12–17 years.
   

People aged 18 years and over were considered to have met the guideline if they usually consumed at least the following number of serves per day:

• six serves for males aged 18–70 years
• five serves for males aged 71 years and over
• five serves for females aged 18 years and over.
   

One serve is approximately half a cup of cooked vegetables or one cup of salad vegetables — equivalent to approximately 75 grams.

Physical activity undertaken by people living in non-remote areas was assessed based on an interpretation of Department of Health guidelines.

• For the 2014 guidelines, the Australia’s Physical Activity and Sedentary Behaviour Guidelines were used, which differ by age group. In this survey, the workplace activity component of the guidelines was excluded.
• For the pre-2014 guidelines, the National Physical Activity Guidelines for Australian Adults were used for all people aged 18 years and over.
   

To meet either set of guidelines, people needed to do varying combinations of some or all of the following physical activities:

• walking for transport

• walking for fitness, recreation or sport

• moderate intensity exercise

• vigorous intensity exercise

• strength or toning activities.
   

In this survey, people aged 15–17 years were considered to have met the guidelines if, in the last week, they did:

• one or more of the following for at least 60 minutes every day: ­walking for transport, walking for fitness, recreation or sport, moderate intensity exercise, or vigorous intensity exercise, and
• some vigorous intensity exercise, and
• strength or toning activities on at least three days.
   

In this survey, people aged 18–64 years were considered to have met the guidelines if, in the last week, they:

• did one or more of the following at least five days: walking for transport, walking for fitness, recreation or sport, moderate intensity exercise, or vigorous intensity exercise, and
• accumulated at least 150 minutes of any combination of the above (vigorous intensity exercise time is multiplied by two), and
• did strength or toning activities on at least two days.
   

In this survey, people aged 65 years and over were considered to have met the guidelines if, in the last week, they did:

• one or more of the following every day: walking for transport, walking for fitness, recreation or sport, moderate intensity exercise, or vigorous intensity exercise, and

• any combination of the above for at least 30 minutes on five or more days.
   

There were two guidelines for people aged 18 years and over. In this survey, people were considered to have met:

• the first guideline if, in the last week, they had accumulated 150 minutes of physical activity from any combination of the following: walking for transport, walking for fitness, recreation or sport, moderate intensity exercise, or vigorous intensity exercise
• the second guideline if, in the last week, they met the first guideline and undertook any of those activities on at least five occasions.
   

For more information about the pre-2014 guidelines, see Australian Aboriginal and Torres Strait Islander Health Survey: Users’ Guide, 2012–13 (cat. no. 4727.0.55.002).

People aged 15 years and over were asked about the extent to which they were regularly smoking tobacco products and using e-cigarettes/vaping at the time of interview.

Tobacco products include:

• manufactured (packet) cigarettes

• roll-your-own cigarettes

• pipes, cigars or other tobacco products.
   

Tobacco products exclude:

• chewing tobacco

• smoking of non-tobacco products (such as marijuana).
   

A person’s smoker status for tobacco products was categorised as:

• current daily smoker — a person who reported they regularly smoked one or more cigarettes, pipes, cigars or other tobacco products per day

• current smoker less than daily — a person who reported they smoked cigarettes, pipes, cigars or other tobacco products less frequently than daily

• ex-smoker — a person who reported they did not currently smoke but had previously either regularly smoked daily, smoked at least 100 cigarettes in their lifetime, or smoked pipes, cigars or other tobacco products at least 20 times in their lifetime

• never smoked — a person who reported they had never regularly smoked daily, smoked less than 100 cigarettes in their lifetime, and smoked pipes, cigars or other tobacco products less than 20 times in their lifetime.
   

An e-cigarette user/vape smoker was a person who uses or has ever used an electronic cigarette, a battery operated device that resembles tobacco cigarettes, pipes or cigars to inhale nicotine and/or other chemicals in a vapour form rather than smoke.

• For e-cigarettes/vapes containing nicotine, people were asked if they had used them in the previous 12 months and, if so, how often.
• For e-cigarettes/vapes excluding nicotine, people were asked whether they had ever used them and, if currently using them, how often.
   

Smoking is likely to be under-reported. Some current smokers may not have identified as such due to social pressures, especially where other household members were present at the interview. The extent to which under-reporting has occurred is not able to be quantified.

Waist circumference is a measurement, in centimetres (cm), of a person’s waist. Measurements were voluntarily taken:

• by the interviewer at the time of interview using a tape measure (maximum 200 cm)
• from people aged two years and over, excluding women who had volunteered that they were pregnant.
   

The waist circumferences of people aged 18 years and over were classified by sex as recommended by the World Health Organization’s 2008 Waist Circumference and Waist-Hip Ratio: Report of a WHO Consultation as:

• not at risk — less than 94 cm for males, or less than 80 cm for females
• increased risk — 94 cm to less than 102 cm for males, or 80 cm to less than 88 cm for females
• substantially increased risk — 102 cm or more for males, or 88 cm or more for females.

People were asked to provide information on their experiences of physical and threatened physical harm in the previous 12 months.

Physical harm refers to any incident where a person was physically hurt or harmed by someone on purpose, including physical fights. Other forms of abuse (e.g. sexual, emotional, psychological) are not included.

Threatened physical harm refers to threats of physical harm that occurred either face-to-face or non-face-to-face (e.g. via instant message/social networking sites, text message, phone, email or writing).

• Due to the sensitive nature of the questions, responses were not compulsory, and a person may have chosen not to answer some or any of the questions.

• The same question wording was used in both non-remote and remote areas.

• This is the first time questions on physical and threatened physical harm have been included in the National Aboriginal and Torres Strait Islander Health Survey.

• The development and testing of the questions was overseen by an expert advisory panel, comprising members from government and non-government agencies.

• The question wording used in 2018–19 was drawn from a variety of ABS surveys and was thoroughly tested in non-remote and remote areas of Australia, including in discrete Indigenous communities.
   

People who had experienced physical harm or face-to-face threatened physical harm in the last 12 months were asked to identify:

• the offender(s) of the most recent incident
• the offender(s) related to all incidents within the last 12 months.
   

People may have experienced physical harm or face-to-face threatened physical harm by more than one offender in the previous 12 months. An offender may have been an Aboriginal or Torres Strait Islander person or a non-Indigenous person.

A person is considered to have experienced family and domestic violence within the context of the survey if they identified an intimate partner or family member as an offender.

An intimate partner is a:

• current partner (husband/wife/defacto)

• previous partner (husband/wife/defacto)

• boyfriend/girlfriend/ex-boyfriend/ex-girlfriend, or

• date.
   

A family member is a:

• parent

• child

• sibling, or

• other family member.
   

Experiences of harm are likely to be under-reported. While the relationship to offender data items can provide an indication of the number of people that have experienced physical harm or face-to-face threatened physical harm, the data does not provide a complete picture of physical harm, or the prevalence of family and domestic violence.

• Interviews are conducted face-to-face with a trained interviewer, but there is no requirement for a private interview setting. People may be less likely to disclose any experiences of physical harm or threatened physical harm by an intimate partner or family member if the offender is present in the home at the time of the interview.
• Some people who have experienced physical harm or threatened physical harm may not have wished to disclose this to the interviewer for other reasons.
   

The physical and threatened physical harm data collected in 2018–19 is not comparable to other ABS data sources collecting similar data, including:

• data for Aboriginal and Torres Strait Islander people from the National Aboriginal and Torres Strait Islander Social Survey (cat. no. 4714.0)
• data for the total population from the General Social Survey, Australia (cat. no. 4159.0)
• data for the total population from the Personal Safety Survey, Australia (cat. no. 4906.0), or
• data by Indigenous status in Recorded Crime – Victims, Australia (cat. no. 4510.0).

Below is a list of topics included in the 2018–19 National Aboriginal and Torres Strait Islander Health Survey (NATSIHS) as well as the degree of change to the questions from the last iteration of the survey in 2012–13. For more detail, see the Data Item List in the Data downloads section. The Data Item List also contains information about whether the item is comparable to the 2012–13 NATSIHS or the 2017–18 National Health Survey.

When making comparisons between populations, it is important to consider whether these groups have different age structures. The Aboriginal and Torres Strait Islander population has a younger population than the non-Indigenous population. To account for the difference in age, the ABS uses a technique called age standardisation to produce proportions that people can use for comparison purposes. It is not recommended to compare results from the NATSIHS to other sources, such as the National Health Survey, if the data has not been age standardised.

In order to allow comparisons, the published results of the 2018–19 NATSIHS include selected data cubes with age standardised proportions presented for both the non-Indigenous and the Aboriginal and Torres Strait Islander populations. Data cubes can be accessed via the Data downloads section.

Age standardisation is a technique used to enhance the comparability of rates between populations with different age structures. As many population characteristics are age-related, (for example, long-term health conditions and employment patterns), adjustments are made to account for the effects of the different age structures on the prevalence of these characteristics.

As age is strongly related to many health measures, estimates of prevalence which do not take account of age may be misleading. The age standardised estimates of prevalence are those rates that ‘would have occurred’ should both the Aboriginal and Torres Strait Islander and non-Indigenous populations have the same age composition. For this reason, where appropriate, estimates for Aboriginal and Torres Strait Islander people and non-Indigenous people have both been age standardised to reflect the age structure of the same population.

The difference between age standardised rates can be expressed through rate ratios. A rate ratio is a ratio calculated by dividing the age standardised proportion of Aboriginal and Torres Strait Islander people with a particular characteristic by the age standardised proportion of non-Indigenous people with the same characteristic.

• A rate ratio of 1.0 indicates the age standardised prevalence of the characteristic is the same in the Aboriginal and Torres Strait Islander and non-Indigenous populations.
• A rate ratio greater than 1.0 indicates the age standardised prevalence of the characteristic is higher in the Aboriginal and Torres Strait Islander population.
• A rate ratio less than 1.0 indicates the age standardised prevalence of the characteristic is lower in the Aboriginal and Torres Strait Islander population.

In the 2018-19 National Aboriginal and Torres Strait Islander Health Survey (NATSIHS), information about hearing was collected in two ways:

• reported by the respondent
• measured using a voluntary hearing test.
   

Respondents were presented with a prompt card and asked whether they had any hearing problems that had lasted, or were expected to last, for at least six months.

Respondents who indicated that they had one or more of the following were considered to have long-term hearing impairment in one or both ears:

• total deafness
• deaf in one ear
• hearing loss or partially deaf.
   

Measurements of hearing were collected from respondents aged seven years and over who did not have a cochlear implant using a voluntary, self-administered test. This was the first time this data has been collected by the ABS.

The ABS worked with the National Acoustics Laboratories, the research division of Hearing Australia, to create a test that respondents could use on the interviewers' laptops out in the field to:

• detect whether a respondent had a hearing impairment in one or both ears
• assess a respondent’s level of hearing impairment where there was a hearing impairment.
   

The hearing test required respondents to listen through headphones to a series of beeps over two audio frequencies (one kilohertz and four kilohertz) and respond to hearing a beep by pressing a key on the laptop. Respondents were given a chance to practice prior to the test being administered.

Respondents who completed the test were given their results on a Measurements Card (available on the Downloads tab). The result for each ear was reported on the card as:

• pass, or
• see your GP or health service.
   

There is variability in the descriptors and ranges used to describe level of hearing impairment both within Australia and internationally. The test categorised the results into the following levels of hearing impairment for each ear, which were based on advice from the National Acoustics Laboratories:

• no measured hearing impairment – quietest sound that can be heard is 20 decibels or lower
• mild hearing impairment – quietest sound that can be heard is between more than 20 decibels and 40 decibels
• moderate hearing impairment – quietest sound that can be heard is between more than 40 decibels and 60 decibels
• severe or profound hearing impairment – quietest sound that can be heard is more than 60 decibels.
   

Respondents with a hearing impairment in both ears were classified by level of hearing impairment based on the ear with the better hearing. For example, respondents with a mild hearing impairment in one ear and a moderate hearing impairment in the other ear were classified as having a mild hearing impairment.

There are limitations with the hearing test – for example, the test is undertaken in the field with background noises, rather than in a soundproof room. However, a comparison of hearing test results with reported hearing impairment can indicate a respondent may have an unreported hearing impairment.

The hearing test had a relatively high rate of non-response due to its voluntary and potentially sensitive nature.

The data from those who undertook the hearing test was then used to impute the data for those who had not taken part in the test. Imputation gives a more complete and useful dataset. The following information was produced from the hearing test:

• summary result code for left ear (normal, mild, moderate, severe or worse) [1]
• summary result code for right ear (normal, mild, moderate, severe or worse) [1]
• whether hearing issue in one or both ears.
   

Missing values were imputed using two steps.

Firstly, all persons aged seven years and over were imputed as having a severe or profound hearing impairment in both ears if they reported they:

• had a cochlear implant

• had total deafness
• had a hearing aid in both ears.
   

Then a 'hot decking' imputation method was used. In this method, a record with a missing response (the 'recipient') receives the response of another similar record (the 'donor'). Due to the low response rates, a donor could be used up to five times to populate recipient records. Persons with imputed values from the first step were excluded from this second step of the imputation process.

After some correlation analysis, a number of characteristics (imputation variables) were used to match recipients to donors:

• sex
• whether uses a hearing aid
• disability status
• highest year of school completed
• proficiency in English
• labour force status
• state/territory of residence

• type of health services available in local area.
   

For example, a female recipient who has a hearing aid in one ear, has a profound disability, has completed Year 10 or higher, speaks English well or very well, is not in the labour force, lives in Tasmania, and has no doctor/GP in the local area will match to a donor record who has the same profile (female, has a hearing aid in one ear, has a profound disability, etc).

Using these variables, all of the eligible recipient records were able to be imputed successfully.

The table below shows the impact of imputation on summary results for left and right ears.

The imputation process meant that a new set of replicate weights had to be created for the imputed hearing test data. This is because the imputation process used donor records (and could use them up to five times), which can artificially lower the Relative Standard Errors. The new set of replicate weights adjusted for this and for the additional uncertainty in the estimates due to the use of imputed values rather than reported values.

Jackknife variance estimation for hot deck imputation was used to create the new replicate weights. This resulted in an increased variance when compared to the un-imputed data, which is to be expected.

Each record also retained the original main weight calculated as part of the normal weighting process – see Response rates, sample counts and estimates (appendix).

1. Two of the labels used for the summary result code, which also appear in the data item list, are referred to by different labels throughout the rest of this appendix and in all hearing test-related commentary. 'Normal' is referred to as 'no measured hearing impairment' and 'severe or worse' is referred to as 'severe or profound'.

This publication contains modelled estimates of health conditions and risk factors for small areas based on data from the 2018-19 National Aboriginal and Torres Strait Islander Health Survey (NATSIHS), 2016 Estimated Resident Population (ERP), the 2016 ABS Census of Population and Housing, and aggregate administrative data sources. The term “small area” generally refers to a geographical area that is smaller than a state or territory, such as Indigenous Regions and Primary Health Networks.

A modelled estimate can be interpreted as the expected number or proportion of people with a health condition or characteristic for an area of Australia based on the demographic information available for that area. The process of producing modelled small area estimates for health conditions measured in the NATSIHS consisted of the following components, described in detail in sections 2.1 to 2.9:

1. Identification of the outcome variables
2. Identification of the geographical areas
3. Selection of the predictor variables
4. Scoping the data
5. Creation of binary and proportion variables
6. Aggregating observations and merging datasets
7. Model selection
8. Final adjustments and outputs
9. Assessment of the modelled estimates
    

From the NATSIHS, modelled small area estimates (counts, proportions, measure of error) have been produced for persons with the following health conditions and risk factors:

• Self-assessed health status, by sex
• Smoking status, by sex
• Body Mass Index, by sex
• Number of long term health conditions, by sex
• Disability status, by sex
• Psychological distress, by sex
• Alcohol long term risk
• Alcohol short term risk
• Substance use
• Number of chronic conditions, by sex
• Specific long term health conditions, by age group

For age groups:

• All ages
• 0 to 39 years
• 40 to 54 years
• 55 years and over
   

For more information about the outcome variables, including definitions, see the footnotes in each Data cube, the Glossary, or Explanatory Notes on the ABS Website.

The modelled estimates for small areas have been produced at the Indigenous Region (IREG) and Primary Health Network (PHN) geographies.

In order to predict outcome variables, predictor variables are required on both the NATSIHS dataset and a small area dataset containing population, Census, and administrative data. Predictor variables were created if data were available for small areas for all of urban, rural, remote and very remote Australia and if there was an expectation that they might be good predictors of the outcome variables.

For age and sex predictor variables, data at the small area level were obtained from ABS ERP data from Estimates of Aboriginal and Torres Strait Islander Australians, June 2016 (Cat. No. 3238.0.55.001). This is described below in section 2.4.

For other demographic variables collected in the NATSIHS, data at the small area level were obtained from the 2016 Census of Population and Housing, as this was the most up-to-date comprehensive source of demographic data due to the depth of information at small geographical levels.

Additional variables that were available at the small area level but not collected in the NATSIHS were also included in the model. These variables included other demographic variables on the Census, geographic variables, and variables from administrative sources.

Predictor variables that relate to the geographical areas where people reside included:

• remoteness area
• socio-economic indexes for areas (SEIFAs) – population-weighted deciles at the Statistical Areas Level 1 (SA1) level
• state and territory
• section of state (major urban/other urban/bounded locality/rural balance)
• Greater Capital City Statistical Area (GCCSA)/balance of state
• design area type (categorises inner city, large and small urban towns, rural towns and remote areas within states and territories for designing the sample of the NATSIHS)
   

Sources of geographical area data included:

• Australian Statistical Geography Standard (ASGS): Volume 5 - Remoteness Structure, July 2016 (Cat. No. 1270.0.55.005)
• Census of Population and Housing: Socio-Economic Indexes for Areas (SEIFA), Australia, 2016 (Cat. No. 2033.0.55.001)
• Australian Statistical Geography Standard (ASGS): Volume 4 - Significant Urban Areas, Urban Centres and Localities, Section of State, July 2016 (Cat. No. 1270.0.55.004)
• Australian Statistical Geography Standard (ASGS): Volume 1 - Main Structure and Greater Capital City Statistical Areas, July 2016 (Cat. No. 1270.0.55.001)
   

Predictor variables obtained from administrative data sources are described in the following table:

Within most types of predictor variables (as discussed above), several separate categories of data items were included. The variables considered for inclusion in the model are listed in the Predictor variables tab of the Datacube.

The modelled estimates for small areas are applicable to persons who were usual residents of private dwellings to match the scope of the NATSIHS. They exclude:

• non-private dwellings, for example hospitals and aged care facilities
   

The base data source used to compile the modelled small area estimates was the ABS Estimated Resident Population (ERP) data from Estimates of Aboriginal and Torres Strait Islander Australians, June 2016 (Cat. No. 3238.0.55.001). Adjustments were made to the ERP data, by using ratios of private to non-private dwellings, calculated from the 2016 Census to match the scope of the NATSIHS, and then summed to the NATSIHS population state by age by sex estimates. These are the ‘population denominator’ estimates included in the Data cube. It is important to note that these population estimates are not official estimates and were created solely for analysis of the NATSIHS modelled small area estimates and will not match other population data at the IREG or PHN geography level.

Adjustments were also made to the Census data, specifically the predictor variables obtained from the Census (described above in section 2.3) to match the scope of the NATSIHS. Persons residing in non-private dwellings were removed from the small area dataset using persons’ dwelling type available on the Census datasets for respondents at home on Census night. However, for persons who were not at home on Census night, information is not collected to determine if the dwelling they usually reside in is a private or non-private dwelling; therefore, their records were deleted from the small area dataset. This data adjustment assumes that the people who were away from home on Census night and live in private dwellings have the same health characteristics as the people who were at home in a private dwelling.

Modelled estimates were not produced for IREGs or PHNs that are entire states. This includes the Tasmania and ACT IREGs; and the Tasmania, NT and ACT PHNs. State-level data should be obtained from the NATSIHS published data or the TableBuilder product, as the NATSIHS sample size is designed to be sufficient at State and Territory level to directly estimate these health statistics. Modelled small area estimates are not designed for use at large geographies such as states.

Additional exclusions that were applied to the data included:

• residents of Other Territories
   

On the NATSIHS dataset outcome variables were created as binary variables to make them suitable for the type of modelling undertaken (logistic regression). For the outcome variables described in section 2.1 binary variables are created for each category of the outcome variable. For example, in the case of Body Mass Index, binary variables are created separately for underweight/normal weight, overweight, and obese. On both the NATSIHS and the small area datasets, predictor variables that were categorical were also created as binary variables. An observation took the value of 1 if an individual had a characteristic of interest and 0 otherwise. For example:

1. in the case of overweight, the outcome variable for overweight took the value of 1 if an individual was overweight and 0 if the individual was not overweight
2. in the case of labour force status, the predictor variable for employed took the value of 1 if an individual was employed and 0 if the individual was unemployed, not in the labour force or aged 0-14 years
    

Binary variables were also created on the small area dataset denoting quintiles of the characteristic of interest. For example:

• for hospital admissions, a binary variable was created to denote whether the person lived in an area in the bottom quintile of admission rates
   

In addition, proportions of an area’s population with the characteristic of interest is also calculated as a predictor variable. For example:

• the proportion of an area’s population having had a hospital admission is recorded as a predictor variable for each small area
   

All data sources were aggregated to a fixed structure (cross classification cell groups) including several levels of geography, five year age group and sex. This decreases the size of the datasets (especially the Census dataset) to increase the efficiency of the modelling process.

The Census, adjusted ERP and administrative datasets were then merged into one small area dataset.

Models were created for each outcome variable, and each category of the outcome variables described in section 2.1 independently. For example, a different model is created and selected for overweight than for obese. However within each outcome variable the same model is used for each output classification, for example geography, age group, and sex.

The model selection method uses the small area dataset to measure the relationship between the outcome variable and possible predictor variables to determine one set of significant predictor variables. This method assumes that the relationships observed in the survey data at State and National levels also hold at the small area level. The significant predictor variables for each model are listed in the Predictor variables tab of the Data cube.

Random effects logistic regression models are used for each outcome variable. As part of any model selection process an appropriate significance level must be chosen for determining which predictor variables to include in the models. The 0.05 (95%) level is most commonly used; however, due to NATSIHS’ relatively large sample sizes, the Bayesian Information Criterion (BIC) was used to reduce the risk of over-fitting.

To verify that the model adequately predicted the outcome variable, the models were applied to small area data, summed to create Australia level modelled estimates and compared with reliable direct survey weighted estimates. This property is known as model additivity. Where model additivity was not similar, additional predictor variables were included in the model until suitable model additivity was achieved.

Using the selected model for each outcome variable, a mixed estimate comprised of modelled and survey data is then produced for each small area output classification (IREG or PHN by sex or age group). A mixed/composite estimate reflects the best trade-off between the accuracy of the direct survey weighted estimate and the error associated with the modelled estimate. For a small area that happens to have a low sampling error (because of a large sample size within that small area, for example), more weight will be given to the direct estimate when calculating a modelled estimate for that small area. On the other hand, for a small area with high sampling error, more weight will be given to the model based prediction as this will be more reliable in calculating the modelled estimate for that small area. This takes advantage of what is known about the small area location from the survey to improve the modelled estimates.

The modelled estimates are then adjusted so that they sum to national direct survey estimates. The adjustment also ensures that estimates for outcome variable categories within a broader outcome category, for example Body Mass Index categories sum to the population within each small area. The associated errors resulting from the modelling process (described in Section 3), which improve on direct survey estimates’ errors, were not adjusted.

The modelled estimates in the Datacube as:

• counts with selected characteristic (number of persons)

• relative error
• proportion
• 95% margin of error of proportion (95% MoE)
• total population (expected number of people in each small area).

The denominators (total population) used to calculate the proportions are the unofficial population estimates for each IREG or PHN (based on adjusted ERP) described above in section 2.4.

To mitigate against the identification of survey respondents, modelled estimates have been confidentialised to ensure they meet ABS requirements for confidentiality. Small area locations (IREGs or PHNs) with populations or modelled counts that didn’t meet the confidentiality rules have modelled estimates comprised solely of the modelled component, rather than the mixed/composite estimator described above. This means that no sampled contribution is included in such modelled estimates, regardless of whether sample exists in these small areas.

One facet of the adjustment process is that the ‘population denominator’ estimates for each small area will not exactly match between outcome variables. The differences are insignificant and are solely due to the adjustment process.

Various measures were taken to examine the modelled estimates. Modelled estimates were compared with direct survey estimates from the NATSIHS for areas that were sampled. For the survey estimates, 95% Confidence Intervals (CIs) were calculated. These were plotted against the modelled estimates to see if the majority of modelled rates fell within the CIs of the NATSIHS estimates.

Relative root mean squared errors (RRMSEs) (described in section 3.4) of the modelled estimates were examined to ensure that the majority were of suitable quality.

The number, range, and applicability of predictor variables included in the models used to create the small area estimates were considered.

Comparisons among the small area estimates and choropleth maps were produced to assess whether the modelled estimates aligned with expectations. Data were confronted with available ABS National level data to assess whether the modelled estimates aligned with expectations.

Please see section 5 for a quality summary for the modelled small area estimates.

The process undertaken in producing modelled estimates overcomes much of the volatility at the IREG or PHN levels caused by sampling error. However, it should be remembered that the modelled estimates produced are still subject to errors.

The errors associated with the modelled small area estimates fall into three categories, as follows:

• 1. sampling error
  2. non-sampling error
  3. modelling error

These errors are combined into an overall measure of accuracy, the relative root mean squared error (RRMSE), described in section 3.4.

Sampling error is introduced into estimates because the NATSIHS data were collected from only a sample of dwellings. Therefore, they are subject to sampling variability; that is, modelled estimates may differ from those that would have been produced if all dwellings had been included in NATSIHS. The smaller the sample obtained within a small area, the greater the sampling error associated with that small area's modelled estimates will be.

The imprecision due to sampling error should not be confused with inaccuracies due to imperfections occurring in the survey process. Such imperfections include mistakes made in reporting by respondents and recording by interviewers, and errors made in coding and processing data. Inaccuracies of this kind are referred to as non-sampling error, and they occur in any enumeration, whether it be a full count (Census) or a sample. Unlike the other sources of error, non-sampling error is not measurable and therefore isn’t accounted for in the measured error (direct or modelled) that accompanies these estimates. Every effort is made to reduce non-sampling error to a minimum through careful design of questionnaires, intensive training and supervision of interviewers, and rigorous procedures; as detailed in the Explanatory Notes.

Modelling error is introduced by model misspecification. This can occur when the choice of model is incorrect, a key predictor variable is left out or an inappropriate predictor variable is included. Therefore, the selected predictor variables chosen in the models may result in inaccurate modelled estimates for certain small areas, particularly those small areas where there isn’t a strong correlation between the available predictor variables and the health conditions. The models that have been chosen have been tested against a range of possible alternative models; however, they are only the most preferred models subject to available data at the time.

A measure of the quality of the modelled estimates is the RRMSE. The RRMSE is used as a measure of prediction error informing how well the models predict the outcome variables. In its calculation it also inherits some aspects of modelling and sampling error. The RRMSE generally decreases as the population size increases, and is used to assess the reliability of modelled estimates.

As a general rule of thumb, estimates with RRMSEs less than 25% are considered reliable for most purposes, estimates with RRMSEs between 25% and 50% should be used with caution and estimates with RRMSEs greater than 50% are considered too unreliable for general use.

In the case of estimates of proportions, estimates with 95% MoEs greater than 10 percentage points are considered too unreliable for general use.

Estimates that were altered by more than 10% due to the adjustment process described in section 2.8 should be used with caution, as the RRMSE and 95% MoE are likely to be smaller than the true error for these estimates.

The small area modelled estimates can be interpreted as the expected number or proportion of people with a health condition or characteristic for a typical area in Australia with the same characteristics. For some small area locations (IREGs or PHNs), there will be differences between the modelled estimates and the actual number of people with the characteristic of interest. One explanation for this is that significant local information about particular small areas exists but has not been collected for all areas and cannot be incorporated into the models. This sort of information is usually not measurable, and relies on local or expert knowledge.

Small area modelled estimates should be viewed as a tool that when used in conjunction with local area knowledge as well as the consideration of the modelled estimates reliability, can provide useful information that can assist in making decisions for small geographic areas. Care needs to be taken to ensure decisions are not based on inaccurate estimates. The provided modelled small area estimates can be aggregated to larger regions (such as regional planning regions) to help improve decision making. Small area estimates can be aggregated together using an approximation formula outlined in section 6. Aggregation of small areas should be done taking into account local knowledge about these areas.

The quality of the modelled estimates were assessed according to the following criteria:

1. the number, range, and applicability of predictor variables included in the models
2. consistency with national direct survey estimates. For example, whether modelled estimates for circulatory system diseases increased proportionally with age
3. median RRMSE, as a measure of prediction accuracy

These culminated in an overall reliability assessment, which has three categories:

• reliable, meaning the modelled estimates are suitable for general use
• less reliable, meaning the modelled estimates should be used with caution
• unreliable, meaning the modelled estimates are unsuitable for general use. Modelled estimates assessed as unreliable are not published.
   

The definitions used in this survey may not be identical to those used for the same or similar items in other surveys. For more information about these differences, refer to the Explanatory notes section and appendices.

A person who identified themselves, or was identified by another household member, as being of Aboriginal origin, or both Aboriginal and Torres Strait Islander origin.

A household where at least one resident has been identified as being of Aboriginal and/or Torres Strait Islander origin.

People who identified themselves, or were identified by another household member, as being of Aboriginal origin, Torres Strait Islander origin, or both Aboriginal and Torres Strait Islander origin.

A person aged 18 years or over.

A technique used to remove age as a factor when comparing characteristics that are age-related (for example, long-term health conditions) between two or more populations with different age structures. See Explanatory notes section.

A risk level assessed using the 2009 National Health and Medical Research Council (NHMRC) guidelines for the consumption of alcohol. See Appendix - assessing health risk factors.

A long-term health condition involving inflammation of the joints often resulting in pain, stiffness, disability and deformity.

A long-term health condition marked by episodes of wheezing, chest tightness and shortness of breath associated with widespread narrowing of the airways within the lungs and obstruction of airflow.

A classification, covering all sectors of the education system (schools, vocational education and training, and higher education), comprising two component classifications — Level of Education and Field of Education. See Australian Standard Classification of Education (ASCED), 2001 (cat. no. 1272.0).

A framework of statistical areas used by the Australian Bureau of Statistics and other organisations to enable the publication of statistics that are comparable and spatially integrated. See Australian Statistical Geography Standard (ASGS).

Comprises Bachelor Degree, Graduate Diploma, Graduate Certificate and Postgraduate Degree.

A group of long-term health conditions of the back or spine including sciatica (nerve pain), disc disorders, back pain/problems not elsewhere classified, and curvature of the spine.

A measurement of the pressure of the blood in the arteries, expressed in the form of, for example, 120/80 mmHg (millimetres of mercury). The higher number is the systolic blood pressure, which measures the pressure in the arteries as the heart pumps blood during each beat. The lower number is the diastolic blood pressure which measures the pressure in the arteries as the heart relaxes before the next beat. See also High blood pressure (measured), Hypertension (high blood pressure), Appendix - physical measurements and Appendix - assessing health risk factors.

An index of weight-for-height, calculated using the formula weight (in kilograms) divided by the square of height (in metres), used to classify people as underweight, normal weight, overweight or obese. See Appendix - assessing health risk factors.

Refers to children aged 0–3 years (that is, children up to 3 years and 11 months of age) receiving breast milk (including expressed milk) from the mother, a wet nurse or a breast milk donor. Exclusive breastfeeding refers to children receiving only breastmilk and no other fluids, food or water, with the exception of vitamins, minerals and medicines where necessary. See Appendix - assessing health risk factors.

A widely used measure of housing utilisation that is sensitive to both household size and composition. See Canadian National Occupancy Standard for information about the criteria used to assess bedroom requirements and households requiring at least one additional bedroom.

A long-term health condition in which the body’s cells grow and spread in an uncontrolled manner. A cancerous cell can arise from almost any cell so cancer can be found almost anywhere in the body.

A Government initiative assisting job seekers in remote areas to gain the skills, training and capabilities needed to find sustainable employment and contribute to their communities through a range of flexible activities. CDP participants were classified as:

• employed if they also had a non-CDP job, or
• unemployed or not in the labour force, depending on their job search activities.
   

A group of long-term health conditions in which the blood flow in the brain is temporarily or permanently affected by blood vessel narrowing or rupture, clot formation or blockage, including stroke.

A person aged 0–17 years.

A long-term health condition characterised by inflammation of the lining of the airways (bronchial tubes) causing mucus production, coughing and difficulty breathing.

A long-term health condition selected for reporting in this survey because it is common, poses significant health problems, has been the focus of population health surveillance efforts, and action can be taken to prevent its occurrence. Includes:

• arthritis

• asthma

• back problems (dorsopathies)

• cancer (malignant neoplasms)

• chronic obstructive pulmonary disease (COPD)

• diabetes (diabetes mellitus)

• heart, stroke and vascular disease (heart disease)

• kidney disease

• mental and behavioural conditions

• osteoporosis.
   

A group of long-term health conditions which cause narrowing of the airways (bronchial tubes) in the lungs, making it difficult to breathe. Includes:

• emphysema

• chronic bronchitis

• severe asthma (where it is difficult to treat and manage the symptoms).
   

A term used in this survey to describe the occurrence of two or more long-term health conditions.

A person has a core activity limitation if they need help, have difficulty, or use aids or equipment with mobility, self-care and/or communication. A core activity limitation is classified as profound, severe, moderate or mild based on their highest level of limitation in any of those activities. See also Disability status.

A person who reported at the time of interview that they regularly smoked one or more cigarettes, pipes, cigars or other tobacco products per day. See Appendix - assessing health risk factors.

A person who reported at the time of interview that they smoked cigarettes, pipes, cigars or other tobacco products less frequently than daily. See Appendix - assessing health risk factors.

Partial or total loss of hearing.

Children aged less than 15 years and full-time secondary or tertiary students aged 15–24 years for whom there is no identified partner or child of their own usually resident in the same household.

A long-term health condition in which blood glucose levels become too high due to the body producing little or no insulin, or not responding to insulin properly. Excludes gestational diabetes.

Includes soft drinks (including those in ready to drink alcoholic beverages), cordials, sports drinks or energy drinks that have been sweetened with artificial sweeteners rather than sugar. Excludes hot tea/coffee sweetened with sugar replacements like ‘Equal’.

Refers to fruit and vegetable consumption and/or sugar sweetened and diet drink consumption.

A person has a disability if they have an impairment which restricts their everyday activities and has lasted, or is expected to last, for at least six months. A person with a disability is classified by whether they have:

• a specific limitation with any core activities (mobility, communication and self-care)
• a specific restriction when participating in schooling or employment activities, or
• no specific limitation with core activities or restriction with schooling or employment activities.
   

See Disability in Explanatory notes.

A geographical location that:

• is bounded by physical or legal boundaries

• has 50 or more Aboriginal and Torres Strait Islander people usually resident

• is inhabited, or intended to be inhabited, predominantly by Aboriginal and Torres Strait Islander people (more than 50% of usual residents)

• has housing or infrastructure (power, water, sewerage) that is managed on a community basis

• usually has services such as schools, health clinics, shops and council depots.
   

A group of long-term health conditions affecting the ear or hearing which include:

• complete deafness, partial deafness and hearing loss not elsewhere classified (in one or both ears)
• diseases of the middle ear and mastoid processes
• diseases of the inner ear

• other diseases of the ear.
   

Refers to a person who uses and/or has ever used an electronic cigarette, a battery operated device that resembles tobacco cigarettes, pipes or cigars to inhale nicotine and/or other chemicals in a vapour form rather than smoke. These devices are designed to simulate the act of smoking tobacco cigarettes but do not involve the burning of tobacco. A range of names are used to describe them, including e-cigs, electronic nicotine delivery systems (ENDS), e-shisha, e-cigars, e-pipes, e-hookas, hookah-pens, and vape-pipes. See Appendix - assessing health risk factors.

A long-term health condition marked by shortness of breath due to damaged air sacs in the lungs.

Persons aged 15 years and over who had a job or business, or who undertook work without pay in a family business for a minimum of one hour per week. Includes persons who were absent from a job or business.

Employed persons who usually work 35 hours or more per week (in all jobs).

Employed persons who usually worked less than 35 hours per week (in all jobs).

See Physical activity.

Refers to walking for fitness, recreation or sport. See also Physical activity.

A person who reported at the time of interview that they did not currently smoke but had either:

• regularly smoked daily
• smoked at least 100 cigarettes in their lifetime, or
• smoked pipes, cigars or other tobacco products at least 20 times in their lifetime.
   

See Appendix - assessing health risk factors.

A group of long-term health conditions affecting the eye or sight which include:

• cataract
• glaucoma
• disorders of the choroid (the vascular layer of the eye) and retina
• disorders of the ocular muscles, binocular movement, accommodation and refraction
• visual disturbances and blindness
• other diseases of the eye and adnexa (structures involved in protecting and/or supporting the function of the eye, such as the eye socket, eyelids and tear system).
   

Refers to two or more persons, one of whom is at least 15 years of age, who are related by blood, marriage (registered or de facto), adoption, step or fostering, and who are usually resident in the same household. A family is identified by the presence of a couple relationship, lone parent-child relationship or other blood relationship, which means some households contain more than one family.

Refers to type of family:

• couple family with no children
• couple family with children
• one parent family
• other family.
   

A classification of households, based families within the household:

• one family households
• multiple family households
• non-family households (lone person and group households).
   

Refers to a usual daily intake of fruit or vegetables. Adequate consumption of fruit or vegetables means the usual daily intake meets or exceeds the number of serves recommended for a person’s age and sex in the National Health and Medical Research Council (NHMRC) 2013 Australian Dietary Guidelines. See Appendix - assessing health risk factors.

An action taken by a person in the two weeks prior to interview or, for admission to hospital, in the 12 months prior to interview, related to their health, including:

• admitted to hospital
• visit to outpatient clinic or casualty/emergency or day clinic
• consultation with general practitioner (GP) and/or specialist
• consultation with dental professional
• consultation with other health professionals (OHP) (see also Other health professional).
   

Selected behaviours, events and circumstances that impact on health, comprising:

• alcohol consumption
• blood pressure (measured)
• body mass (e.g. overweight or obese)
• breastfeeding
• consumption of sugar sweetened and diet drinks
• fruit and vegetable intake
• immunisation
• physical activity
• physical harm or threatened physical harm
• removal from natural family
• smoking
• substance use
• unfair treatment
• waist circumference.
   

Partial or complete loss of hearing in one or both ears based on results of voluntary, self-administered hearing test undertaken by respondents without a cochlear implant at the time of interview. For people with a hearing impairment in both ears, the level of hearing impairment is classified as mild, moderate, or severe or profound based on the ear with the lowest level of impairment. See Hearing data (appendix).

A long-term health condition marked by partial or complete loss of hearing in one or both ears. See also Ear or hearing problems.

A group of long-term health conditions which includes:

• ischaemic heart disease (including heart attack and angina)
• cerebrovascular disease (including stroke)
• heart failure
• oedema (fluid retention)
• diseases of arteries, arterioles and capillaries.
   

A measured blood pressure reading of 140/90 mmHg (millimetres of mercury) or higher, voluntarily taken at the time of interview and so does not necessarily indicate a long-term condition. In this survey, measured high blood pressure is distinguished from hypertension which is self-reported as a long-term health condition. See also Hypertension (high blood pressure), Appendix - physical measurements and Appendix - assessing health risk factors.

High sugar levels in blood or urine. See also Diabetes (diabetes mellitus).

An area of land with which Aboriginal and Torres Strait Islander people have ancestral and/or cultural links.

One or more persons, at least one of whom is aged 18 years or over, usually resident in the same private dwelling.

The sum of the personal cash incomes of all household members aged 15 years and over, presented in dollars and deciles and in reported and equivalised form. See Explanatory notes section.

A person aged 18 years or over who is nominated as the best person to provide information about the household as a whole, such as household income and tenure arrangements. The person does not need to be selected for the survey or be of Aboriginal and/or Torres Strait Islander origin to act as household spokesperson.

A long-term health condition in which the blood pressure in the arteries is elevated, requiring the heart to work harder than normal to circulate blood through the blood vessels. In this survey, hypertension is distinguished from high blood pressure (measured), which is a blood pressure reading taken at the time of interview and does not necessarily indicate a long-term health condition. See also Blood pressure.

Refers to a classification developed by the ABS for use in ABS health surveys based on the 10th revision of the International Classification of Diseases and Health Related Problems. See also Type of condition.

Refers to influenza and pneumococcus vaccinations only. According to the Australian Government Department of Health’s Australian Immunisation Handbook:

• annual influenza vaccination is recommended for all persons aged 15 years and over
• the number of recommended pneumococcal vaccines depends on age, Indigenous status and the presence of a condition(s) associated with an increased risk of invasive pneumococcal disease.
   

A person has an impairment if they have a loss or abnormality in body structure or physiological function, including mental functions. Abnormality refers to a significant variation from established statistical norms. Examples of impairment are loss of sight, loss of a limb, disfigurement or deformity, impairment of mood or emotion, impairment of speech, hallucinations, loss of consciousness, and any other lack of function of body organs. See Disability in Explanatory notes.

The highest level of the Indigenous Structure of the 2016 Australian Statistical Geography Standard (ASGS). See Australian Statistical Geography Standard (ASGS): Volume 2 - Indigenous Structure, July 2016 (cat. no. 1270.0.55.002).

Refers to whether the person is of Aboriginal and/or Torres Strait Islander origin, as identified by the household spokesperson so not necessarily self-identified. Status is classified as:

• Aboriginal
• Torres Strait Islander
• both Aboriginal and Torres Strait Islander
• neither Aboriginal nor Torres Strait Islander.
   

A long-term health condition, also called coronary artery disease, involving the build-up of plaque (fatty material) in the heart’s arteries, causing them to narrow, reducing blood flow and oxygen to the heart (ischaemia). It includes angina (chest pain and discomfort) and heart attack.

See Psychological distress and Appendix - mental health and wellbeing.

A long-term health condition, also called renal disease, in which a person’s kidney function is reduced or damaged, affecting its ability to filter blood.

For any group, the labour force (employed persons plus unemployed persons) expressed as a percentage of the civilian population aged 15 years and over in the same group.

Identifies whether a person is employed, unemployed or not in the labour force.

Refers to the lifetime risk guideline from the National Health and Medical Research Council (NHMRC) guidelines 2009 Australian Guidelines to Reduce Health Risks from Drinking Alcohol. A person is considered to have exceeded the guideline if they consumed more than two standard drinks per day on average in the last week. See Appendix - assessing health risk factors.

A person has a limitation if they have difficulty, need assistance from another person, or use an aid or equipment, to do a particular core activity (mobility, communication and self-care). The level of the limitation with core activities is classified as profound, severe, moderate or mild, based on the level of support required. See Disability in Explanatory notes.

A condition of the eye where the light that comes into the eye does not directly focus on the retina but behind it, causing the image of a close object to be out of focus, but that of a distant object to be in focus.

An illness, injury or disability which has lasted at least six months, or which the person expects to last for six months or more.

• Asthma is classified as current if the person reported at the time of interview they were having symptoms or treatment. To be current, symptoms of asthma or treatment for asthma must have occurred in the last 12 months.
• Asthma, arthritis, cancer, osteoporosis, diabetes (excluding gestational diabetes), sight and hearing problems are assumed to be long-term.
• Heart attack, angina, heart failure and stroke are assumed to be both current and long-term.
   

See also Chronic condition.

See High blood pressure (measured) and Appendix - Physical measurements.

For any distribution, the median value is that which divides the relevant population into two equal parts, with half falling below and half exceeding that value. For example, the median height is the height at which half the population is taller and half is shorter.

A group of long-term health conditions that affect mood, thinking and behaviour which includes:

• organic mental problems
• alcohol and drug problems
• mood (affective) disorders such as depression
• anxiety-related problems, and
• other mental and behavioural problems.
   

The smallest geographical unit in the Australian Statistical Geography Standard (ASGS). Mesh Blocks form the basis for the larger regions of the ASGS such as Remoteness Areas.

A measure of volume, commonly associated with cooking and serving sizes, equal to 250 millilitres.

Physical activity that causes a moderate increase in the person’s heart rate or breathing, such as gentle swimming, social dancing, and weight lifting. Excludes:

• walking for transport
• walking for fitness, recreation or sport
• household chores, gardening or yard work, and
• any activity done as part of person’s job.
   

See Appendix - assessing health risk factors.

A measure of how a person perceives their level of social support from family and friends, derived from a modified version of the Multidimensional Scale of Perceived Social Support, which uses six questions instead of 12. The scale is used to derive a family score, a friends score and a total score which indicate whether a person perceives the level of social support from each as low, moderate or high. See Appendix - mental health and wellbeing.

A new growth of abnormal tissue (a tumour) that is either benign (non-cancerous) or malignant (cancerous).

A person who at the time of interview reported they had:

• never regularly smoked daily,
• smoked less than 100 cigarettes in their lifetime, and
• smoked pipes, cigars or other tobacco products less than 20 times in their lifetime.
   

See Appendix - assessing health risk factors.

Refers to the Major Cities, Inner Regional and Outer Regional Remoteness Areas combined. This grouping is generally used for comparing non-remote areas with remote areas.

A qualification awarded for educational attainments other than those of pre-primary, primary or secondary education. Includes qualifications at the following levels:

• Postgraduate Degree
• Master Degree
• Graduate Diploma and Graduate Certificate
• Bachelor Degree
• Advanced Diploma and Diploma, and
• Certificates I, II, III and IV.
   

Persons who are not employed or unemployed as defined, including persons who:

• are retired
• no longer work
• do not intend to work in the future
• are permanently unable to work, or
• have never worked and never intend to work.
   

See Diet.

A long-term health condition which thins and weakens bone mineral density, generally caused by loss of calcium, and which leads to increased risk of fracture.

Health professionals other than dentist, general practitioner (GP) or specialist. Includes:

• Aboriginal health worker
• accredited counsellor
• acupuncturist
• alcohol and drug worker
• audiologist/audiometrist
• chemist (for advice only)
• chiropodist/podiatrist
• chiropractor
• dietitian/nutritionist
• herbalist
• hypnotherapist
• naturopath
• nurse
• occupational therapist
• optician/optometrist
• osteopath
• physiotherapist/hydrotherapist
• psychologist
• social worker/welfare officer
• speech therapist/pathologist
• traditional healer.
   

A middle ear infection.

A score, derived from a set of seven questions, which measures the extent to which a person feels control over life outcomes. See Appendix - mental health and wellbeing.

Refers to any or all of the following activities:

• walking for transport (walking that was continuous for at least 10 minutes for the purpose of getting to and from places)
• walking for fitness, recreation or sport (walking that was continuous for at least 10 minutes for fitness, recreation or sport)
• moderate intensity exercise
• vigorous intensity exercise
• strength or toning activities
• workplace activity (physical activity undertaken in the workplace on a typical day, categorised as mostly sitting, mostly standing, mostly walking, or mostly heavy labour or physically demanding work).
   

See Appendix - assessing health risk factors.

Refers to any or all of the following activities:

• playing football/soccer
• playing netball/basketball
• playing softball/cricket
• swimming
• running
• hunting/gathering bush foods/fishing
• dancing (including ceremonial dancing)
• housework/gardening/heavy yardwork
• walking to places
• other.
   

Refers to the ABS’ interpretation of the physical activity (excluding workplace activity) component of the following Department of Health guidelines:

• Australia's Physical Activity and Sedentary Behaviour Guidelines (2014 guidelines)
• National Physical Activity Guidelines for Australian Adults (pre-2014 guidelines).
   

See Appendix - assessing health risk factors.

Refers to any incident where a person was physically hurt or harmed by someone on purpose, including physical fights. Other forms of abuse (e.g. sexual, emotional, psychological) are excluded. See Appendix - physical and threatened physical harm data.

Refers to the number of cases of a particular characteristic (e.g. a specific long-term condition such as cancer) that are present in a population at one point in time. It differs from incidence, which refers to the number of new cases of a particular characteristic that occur within a certain period (e.g. number of new cases of cancer in a calendar year).

Refers to a house, flat, unit or any other structure used as a private place of residence at the time of survey.

Refers to a person with a profound or severe limitation when performing selected tasks related to communication, mobility or self-care. See Disability status and Explanatory notes section.

A person who answers the survey questions on behalf of the person selected for the interview when the person selected is:

• incapable of answering for themselves (e.g. due to illness/injury or cultural considerations)
• a child aged 14 years or under
• a child aged 15–17 years when parental consent is not given to interview them personally.
   

A measure of non-specific psychological distress experienced recently, derived from a modified version of the Kessler Psychological Distress Scale (K10) called the Kessler 5 (K5). See Appendix - mental health and wellbeing.

A ratio calculated by dividing the age standardised proportion of Aboriginal and Torres Strait Islander people with a particular characteristic by the age standardised proportion of non-Indigenous people with the same characteristic. See Explanatory notes section.

Refers to the Remote and Very Remote Remoteness Areas combined. This grouping is generally used for comparing non-remote areas with remote areas.

Refers to a person and/or any of their relatives who have ever been taken away from their natural family as a child by the government, or been taken away to a mission.

A measure of relative access to services which is used to divide Australia into five classes of remoteness:

• Major Cities
• Inner Regional
• Outer Regional
• Remote, and
• Very Remote.
   

See Australian Standard Geography Standard (ASGS): Volume 5 — Remoteness Structure, July 2016 (cat. no. 1270.0.55.005).

A person has an education or employment restriction if they have difficulty participating, need assistance from another person or use an aid or equipment in schooling or employment. See Disability in Explanatory notes.

See Chronic condition.

A person's general assessment of their health as excellent, very good, good, fair or poor.

A condition of the eye where the light that comes into the eye does not directly focus on the retina but in front of it, causing the image of a distant object to be out of focus, but that of a close object to be in focus.

Refers to the single occasion risk guideline from the National Health and Medical Research Council (NHMRC) 2009 Australian Guidelines to Reduce Health Risks from Drinking Alcohol. A person is considered to have exceeded the guideline if they consumed more than four standard drinks on at least one day in the last 12 months. See Appendix - assessing health risk factors.

Refers to the extent to which a person was regularly smoking tobacco products at the time of interview. See Appendix - assessing health risk factors.

Refers to four Indexes compiled by the ABS following the 2016 Census of Population and Housing, summarising different aspects of the socio-economic condition of areas. The Index of Relative Socio-economic Disadvantage is the one most frequently used in health analysis. See Census of Population and Housing: Socio-Economic Indexes for Areas (SEIFA), Australia (cat. no. 2033.0.55.001).

A drink of alcohol containing 12.5 millilitres (mLs) of alcohol.

Activities designed to increase muscle strength or tone, such as lifting weights, resistance training, pull ups, push ups, or sit ups. See Appendix - assessing health risk factors.

A long-term health condition that occurs when the blood supply to the brain is restricted by a blockage or bleeding, causing damage to the affected tissue which may cause paralysis, speech impairment, loss of memory and reasoning ability, coma or death.

The use of substances for non-medical purposes by a person in the 12 months prior to interview including:

• pain killers or analgesics
• tranquillisers or sleeping pills
• amphetamines, ice or speed
• marijuana, hashish or cannabis resin
• heroin
• methadone
• cocaine
• hallucinogens (LSD/synthetic/naturally occurring)
• ecstasy or other designer drugs
• petrol
• other inhalants
• kava
• other substances.
   

Includes soft drinks (including those in ready to drink alcoholic beverages), cordials, sports drinks or energy drinks that have been sweetened with sugar. Excludes fruit juice, flavoured milk, ‘sugar free’ drinks, and hot tea/coffee. See also Diet drinks.

Refers to threats of physical harm that occurred either face-to-face or non-face-to-face (e.g. via instant message/social networking sites, text message, phone, email, writing). See Appendix - physical and threatened physical harm data.

A person who identified themselves, or was identified by another household member, as being of Torres Strait Islander origin, or both Torres Strait Islander and Aboriginal origin.

Refers to the type of long-term health condition, which uses a classification developed by the ABS for use in ABS health surveys based on the 10th revision of the International Classification of Diseases and Health Related Problems (ICD–10).

Persons aged 15 years and over who were not employed and actively looking for work in the four weeks prior to the survey, and were available to start work in the week prior to the survey.

For any group, the number of unemployed people expressed as a percentage of the labour force in the same group.

Refers to when a person reported they had been treated unfairly because they are of Aboriginal or Torres Strait Islander origin.

See Health action.

Physical activity that causes a large increase in the person’s heart rate or breathing, such as jogging, cycling, aerobics, or competitive sport. Excludes:

• walking for transport
• walking for fitness, recreation or sport
• household chores, gardening or yard work, and
• any activity done as part of a person’s job.

See Appendix - assessing health risk factors.

A measurement, in centimetres, of a person’s waist. It is based on the midway point between the bottom of a person’s ribs and the top of their hip bone, and used to classify people as at increased risk of developing chronic conditions or not at risk. See Appendix - assessing health risk factors.

For information on the institutional environment of the Australian Bureau of Statistics (ABS), including the legislative obligations of the ABS, financing and governance arrangements, and mechanisms for scrutiny of ABS operations, please see ABS Institutional Environment.

Information from the 2018–19 National Aboriginal and Torres Strait Islander Health Survey (NATSIHS) contributes to existing data on Aboriginal and Torres Strait Islander people and the formulation of government policies and legislation.

The 2018–19 NATSIHS collected information on a range of topics including:

• long term health conditions
• health actions and health service use
• nutrition
• physical activity
• physical measurements including a hearing test
• risk factors such as alcohol consumption, discrimination, smoking and substance use
• experiences of harm
• medications
• social and emotional wellbeing
• cultural identification
• language
• general demographic information
• personal and household characteristics
• education and employment
• income.

The NATSIHS was conducted from 1 July 2018 to 13 April 2019.

A summary of findings, including a broad set of tables in spreadsheet format was available on the ABS website on 11 December 2019.

For individuals who wish to undertake more detailed analysis of the NATSIHS data, detailed microdata was released via the DataLab on 11 December 2019. A TableBuilder product will be released, subject to the approval of the Australian Statistician.

The 2018–19 NATSIHS sample was designed to produce reliable estimates by remoteness areas, and at the national level and state/territory levels.

The sample for the non-community component was selected at random using a multi-stage area sample of addresses from the ABS's Address Register. The sample for the community component was selected from the ABS's Dwelling Register for Aboriginal and Torres Strait Islander Communities. After sample loss and non-response, the final sample achieved included approximately 6,400 private dwellings and 10,600 persons.

Estimates in this publication are subject to both sampling and non-sampling errors. Sampling error is the error associated with taking a sample of dwellings rather than going to all dwellings in Australia. In this publication the sampling error is measured by the relative standard error (RSE), which is the standard error expressed as a percentage of the estimate, and the margin of error (MoE), which describes the distance from the population value that the sample estimate is likely to be within for a given level of confidence. Non-sampling errors can occur in any data collection, whether based on a sample or a full count such as a census. Sources of non-sampling error include:

• non-response
• errors in reporting by respondents or recording answers by interviewers
• errors in coding or processing of data.
   

Every effort was made to reduce the non-sampling error by careful design and testing of questions, training interviewers, follow-up of respondents and extensive editing and quality control procedures at all stages of data processing.

Estimates, RSEs and MoEs in this publication have been assessed to ensure the confidentiality of individuals and dwellings contributing to the survey. Estimates in this publication have been randomly adjusted using the statistical process of perturbation to ensure confidentiality of respondents. In most cases, perturbation will have only a small impact on the estimate, while ensuring the information value of the published data as a whole is not impaired.

This is the fourth health survey of Aboriginal and Torres Strait Islander people conducted by the ABS. The previous surveys were conducted in 2012-13 (as part of the Australian Health Survey), 2004–05 and 2001.

Information about the comparability of each data item to the previous release in 2012–13, as well as to the 2017–18 National Health Survey, can be found in the Data Item List via the Data downloads section.

This publication contains tables and a summary of findings to assist with the interpretation of the results of the survey. Detailed Methodology, a Technical Note on Reliability of Estimates and a Glossary are also included, providing information on the terminology, classifications and other technical aspects associated with these statistics.

Estimates and associated RSEs and MoEs for proportions are available in Excel spreadsheets, which can be accessed from the Data downloads section.

Detailed microdata was released on the ABS website on 11 December 2019. It is expected that a TableBuilder will be produced from the NATSIHS, subject to the approval of the Australian Statistician. For further details, refer to the Microdata Entry Page on the ABS website.

Special tabulations of NATSIHS data are available on request for a fee. Tabulations can be produced from the survey subject to confidentiality and sampling variability constraints.