4727.0.55.001 - Australian Aboriginal and Torres Strait Islander Health Survey: First Results, Australia, 2012-13  
ARCHIVED ISSUE Released at 11:30 AM (CANBERRA TIME) 27/11/2013  First Issue
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EXPLANATORY NOTES

INTRODUCTION

1 This publication presents the first results from the 2012-13 Australian Aboriginal and Torres Strait Islander Health Survey (AATSIHS). Collectively AATSIHS encompasses the following three components of the Aboriginal and Torres Strait Islander sample that forms part of the wider ABS Australian Health Survey (AHS) programme:

  • The National Aboriginal and Torres Strait Islander Health Survey (NATSIHS);
  • The National Aboriginal and Torres Strait Islander Nutrition and Physical Activity Survey (NATSINPAS); and
  • The National Aboriginal and Torres Strait Islander Health Measures Survey (NATSIHMS).

2 The AATSIHS expands on information collected in previous National Aboriginal and Torres Strait Islander Health Surveys. For the first time the AATSIHS provides prevalence estimates of certain chronic diseases and conditions, selected behavioural risk factors and objective biomedical measures of selected chronic diseases, nutrition status and other risk factors. This has allowed for the examination of health risk factors and outcomes for different population groups of interest, such as different age groups and people living in remote and non-remote areas.

3 Additional information from the AATSIHS will provide a platform for a range of new research into health determinants and patterns. This will have been achieved by combining the results of objective biomedical tests with self-reported survey-based results for a range of health conditions such as circulatory disease, diabetes and kidney disease. It is well recognised that such diseases are responsible for shortening the lives of many Aboriginal and Torres Strait Islander people. By enabling comparisons with data for the general population, this survey will support critical assessment of progress in 'Closing the Gap' health outcomes.

4 The following information will focus on the National Aboriginal and Torres Strait Islander Health component of the AATSIHS, referred to hereafter as the 2012-13 NATSIHS. For more information about the structure of the AATSIHS, see: The Structure of the AATSIHS.

5 The 2012-13 NATSIHS was conducted throughout Australia in remote and non-remote areas from April 2012 to February 2013. The previous NATSIHS was conducted in 2004-05 (cat. no. 4715.0). Some comparable content was also collected in the 2008 and 2002 National Aboriginal and Torres Strait Islander Social Surveys (cat. no 4714.0).

6
Throughout this release, the term 'Aboriginal and Torres Strait Islander people' refers to all persons who identified themselves as being of Aboriginal, Torres Strait Islander, or both Aboriginal and Torres Strait Islander origin. Information presented on Aboriginal persons includes data on persons identified as having both Aboriginal and Torres Strait Islander origin. Similarly, information on Torres Strait Islanders also includes persons identified as having both Aboriginal and Torres Strait Islander origin. An Aboriginal and Torres Strait Islander household refers to a household with at least one Aboriginal and Torres Strait Islander usual resident.

7
The 2012-13 NATSIHS collected information on a range of demographics from over 9,000 Aboriginal and Torres Strait Islander people of all ages. This release presents summary tables by three population groups:
  • Aboriginal and Torres Strait Islander people aged 15 years and over;
  • Aboriginal and Torres Strait Islander adults aged 18 years and over;
  • and Aboriginal and Torres Strait Islander children aged 0-17 years.

8
Where appropriate, additional comparisons between the 2012-13 and 2004-05 NATSIHS and 2008 and 2002 NATSISS have been included in the summary text.

9 This release also includes data cubes that enable comparisons to the non-Indigenous population of the 2011-12 Australia Health Survey (AHS).

10 Explanations of terms and concepts are provided in the Glossary and a list of data items currently available from the survey can be found in the Australian Aboriginal and Torres Strait Islander Health Survey: Users' Guide, 2012-13 (cat. no. 4727.0.55.002), referred to throughout this publication as the 'Users' Guide'. Further information to assist in the interpretation of the survey will be progressively added to the Users' Guide in December 2013.

SCOPE AND COVERAGE OF THE SURVEY

11
The scope of the survey was all Aboriginal and Torres Strait Islander people who were usual residents of private dwellings in Australia. Private dwellings are houses, flats, home units and any other structures used as private places of residence at the time of the survey. People usually resident in non-private dwellings, such as hotels, motels, hostels, hospitals, nursing homes, and short-stay caravan parks were not in scope. Usual residents are those who usually live in a particular dwelling and regard it as their own or main home.

12 Further scope exclusions for this survey were:
  • Non-Indigenous persons;
  • Non-Australian diplomats; diplomatic staff and members of their household;
  • Members of non-Australian Defence forces stationed in Australia and their dependents; and
  • Overseas visitors.

13 The survey excluded visitors to private dwellings, except for those that had been resident six months or longer. Visitors who were a usual resident of another dwelling and were in-scope of the survey may be selected in the survey only at their usual residence dwelling, or if not selected, would have been represented by similar persons who were selected in the survey.

14 The 2012-13 NATSIHS was conducted in remote and non-remote areas in all states and territories of Australia, including discrete Aboriginal and Torres Strait Islander communities.

15 Coverage exclusions apply to those people who were part of the in-scope population, but who were not included in the sampling frame. The sample was based on where Aboriginal and Torres Strait Islander households were identified in the 2011 Census of Population and Housing. Coverage exclusions applied to manage enumeration costs, included:
  • Statistical Areas Level 1 (SA1s), or Collection Districts (CDs) in the Northern Territory (NT) with no Aboriginal and Torres Strait Islander households;
  • Some discrete Aboriginal and Torres Strait Islander communities with a small number of Aboriginal and Torres Strait Islander households; and
  • Some SA1s, or CDs in the NT, in remote areas with a small number of Aboriginal and Torres Strait Islander households.

16 These coverage exclusions result in an estimated undercoverage of approximately 4% of Aboriginal and Torres Strait Islander persons in Australia. Although these areas were not enumerated, the final sample was weighted to population benchmarks to account for these exclusions. Further information on undercoverage is provided in paragraph 69 and more information on the scope and coverage of the survey will be provided in the Users' Guide.

17
The estimated resident Aboriginal and Torres Strait Islander population living in private and non-private dwellings at 30 June 2011 was 669,881. Excluding persons in non-private dwellings, there were 638,234 Aboriginal and Torres Strait Islander people estimated in the 2012-13 NATSIHS.

18
Population benchmarks, which align with the survey scope, are based on the most recently released Estimated Resident Aboriginal and Torres Strait Islander Population (ERP), which in this case are for 30 June 2011. The ERP data are based on the 2011 Census of Population and Housing, adjusted by the 2011 Post-Enumeration Survey (PES). More information about the Estimated Resident Aboriginal and Torres Strait Islander Population can be found in Estimates of Aboriginal and Torres Strait Islander Australians, June 2011 (cat. no. 3238.0.55.001).

SAMPLE DESIGN

19
The 2012-13 NATSIHS was designed to produce reliable estimates at the national level and for each state and territory. For selected states and territories, that is New South Wales (NSW) Queensland (Qld), Western Australia (WA) and the NT, the sample for children aged 0-14 years and persons aged 15 years and over was allocated to produce estimates that have a relative standard error (RSE) of no greater than 25% for characteristics that at least 5% of these populations would possess. The survey was also designed to provide reliable estimates at the national level for children aged 0-3 years, with the same RSE requirements.

20 As with previous ABS Aboriginal and Torres Strait Islander surveys, additional sample was collected in the Torres Strait Area, to ensure data of sufficient quality would be available for the Torres Strait Area and the remainder of Qld.

21 Funding was received from the Australian Government Department of Health as well as the National Heart Foundation of Australia.

22 The survey design incorporated a sample of discrete Aboriginal and Torres Strait Islander communities (including any out-stations associated with them), referred to as the 'community sample', and a sample of dwellings in areas not covered by the community sample, referred to as the 'non-community' sample. The samples for community and non-community areas were designed separately, with each involving a multistage sampling process.

23 In NSW, Qld, WA, South Australia (SA) and the NT the sample design differed by community and non-community areas.

24 In Victoria (Vic), Tasmania (Tas) and the Australian Capital Territory (ACT) the sample design was the same throughout, corresponding with the method used in non-community areas of the other states and territories.

25 The community sample was obtained from a random selection of discrete Aboriginal and Torres Strait Islander communities and out-stations using a specially developed Indigenous Community Frame (ICF). This frame was constructed using counts from the 2006 Census of Population and Housing and information collected in the Indigenous Location Database (ILDB). All communities on this frame were in remote (or very remote) areas of NSW, Qld, WA, SA and the NT. From this frame 63 communities were selected for enumeration, 5 of which were not enumerated at all because of either occupation, health and safety concerns, closure of communities or lack of accommodation facilities in some locations (see paragraph 90). A random selection of dwellings was made within the selected communities and out-stations, with different selection procedures applied to the main communities and out-stations. Within each selected dwelling, up to one Aboriginal and Torres Strait Islander adult (aged 18 years and over) and up to one Aboriginal and Torres Strait Islander child (aged 0-17 years) were randomly selected to participate in the survey.

26 In non-community areas, dwellings were selected using a stratified multistage area sample. Mesh block level information within SA1s (and CDs used in NT) were used to assist in targeting Aboriginal and Torres Strait Islander people. The NT frame was still based on CDs as changing to an SA1 frame made it more difficult to control overlap. As all areas within Australia are in-scope, a CD or SA1 frame still covers the same areas within NT. A sample of SA1s (or CDs in NT) were randomly selected, with the likelihood of selection based on the number of Aboriginal and Torres Strait Islander dwellings recorded in the area from the 2006 or 2011 Census. Ideally selections would be conducted using Aboriginal and Torres Strait Islander counts from Census 2011, however, this was not feasible for all selections due to the availability of Census 2011 data. All households in Mesh Blocks within the SA1 (or CDs in NT) were then screened to assess their usual residents' Indigenous status. Mesh Blocks or CDs containing no Aboriginal and Torres Strait Islander households were either excluded on coverage or randomly sampled for screening. This approach significantly reduced screening effort in areas of low Aboriginal and Torres Strait Islander population density, such as major capital cities. In remote and very remote areas, all households were screened in selected SA1s and CDs. For each randomly selected dwelling within the selected Mesh Block or CD, one usual resident aged 18 years or over, was asked whether anyone in the household was of Aboriginal and/or Torres Strait Islander origin. This screening question was used to identify Aboriginal and Torres Strait Islander households, from which the sampling process was undertaken for participants in the survey. Within each identified Aboriginal and Torres Strait Islander household, non-remote areas had up to two adults (aged 18 years and over) and two children (aged 0-17) randomly selected, while remote areas only had one adult (aged 18 years and over) and up to one child (aged 0-17) selected per household.

27 Further information on sample design will be provided in the Users' Guide.

REMOTENESS

28
The Australian Statistical Geography Standard (ASGS) is used by the ABS for the collection and dissemination of geographically classified statistics. For the purposes of the 2012-13 NATSIHS, Australia is divided into five remoteness categories:
  • Major cities;
  • Inner regional areas;
  • Outer regional areas;
  • Remote areas; and
  • Very remote areas.

29 These categories are based on the Accessibility/Remoteness Index of Australia (ARIA), which measures the remoteness of a point based on the physical road distance to the nearest urban centre.

30
For this release, the remoteness categories are generally presented as:
  • Major Cities of Australia;
  • Inner Regional Australia;
  • Outer Regional Australia;
  • Remote Australia; and
  • Very Remote Australia.

31 Additionally, regions may also be referred to as 'remote' (includes Remote and Very remote) or 'non-remote' (includes Major cities, Inner and Outer regional areas).

32
More information on the ASGS is available in the Australian Statistical Geographical Standard (ASGS), July 2011 (cat no. 1270.0.55.001).

DATA COLLECTION

33
After screening households in non-community areas, approximately 2.6% were identified as having an Aboriginal and Torres Strait Islander usual resident. Of these households, 74% responded to the survey. This response rate does not take into account approximately 11% of households who were unable to be contacted and therefore the Indigenous status of their usual residents could not be determined. In communities, 77% of in-scope households were fully responding.

34
Some survey respondents provided most of the required information, but were unable or unwilling to provide a response to certain data items. The records for these persons were retained in the sample and the missing values were recorded as 'don't know' or 'not stated'. No attempt was made to deduce or impute for these missing values.

35 ABS interviewers undertook personal interviews at selected private dwellings. Interviews were predominantly conducted using a Computer-Assisted Interviewing (CAI) questionnaire. CAI involves the use of a notebook computer to record, store, manipulate and transmit the data collected during interviews.

36
Prior to enumeration, ABS interviewers participated in cultural awareness training, which provided information specifically developed for surveys involving Aboriginal and Torres Strait Islander people. The training outlined the ABS protocol for conducting surveys in community areas and described cultural considerations for interviewers.

37 To take account of language and cultural differences in community areas, the collection method varied for remote and non-remote areas. Some questions for remote areas were reworded to enhance respondent understanding of the concepts (e.g. oral health). Additionally, the survey content in remote areas excluded topics for which data quality was considered problematic to collect or not applicable.

38 In communities, where possible, ABS interviewers were accompanied by local Aboriginal and Torres Strait Islander facilitators who assisted in conducting interviews. The facilitators explained the purpose of the survey, introduced the interviewers, assisted in identifying usual residents of a household and in locating residents who were not at home. They may have also assisted respondents to understand the survey questions. A Community Information Form (CIF) was also used to collect general information from the Community Council Office to assist in the conduct of interviews in community areas.

39 Since the survey content sometimes differed in remote/non-remote areas, not all data items are available for the total Aboriginal and Torres Strait Islander population. In the data item list, data collected only in remote areas is noted as such. There are also data items which have been adjusted to allow for remote and non-remote comparisons, which are denoted as such. For example, the disability status item is available for 'non-remote only' or as a 'remote/non-remote comparison'. For more information refer to the Users' Guide.

40 One person in the household, aged 18 years and over, provided basic household information, including Indigenous status, age, sex and relationships, for all household members. This person, or an elected household spokesperson, also answered some financial and housing items, such as income, tenure arrangements and household facilities.

41 Personal interviews were conducted with selected Aboriginal and Torres Strait Islander persons aged 15 years and over. Exceptions occurred where the selected person:
  • was unable to complete the survey due to injury or illness (a proxy interview may have been arranged);
  • was mourning the death of a family member (Sorry Business); or
  • did not have sufficient English skills and an interpreter was unable to be arranged.

42 Where consent for interview was not given by a parent or guardian of an Aboriginal and Torres Strait Islander person aged 15-17 years, a personal interview was not conducted.

43 Aboriginal and Torres Strait Islander persons aged 15-17 years could choose to have their interview completed by a parent or guardian. 38% of interviews were conducted by proxy for this age group.

44 More information on data collection and a copy of the survey questionnaire will be provided in the Users' Guide.

SURVEY CONTENT

45
Broadly, the 2012-13 NATSIHS collected information on a range of demographic and health characteristics of Aboriginal and Torres Strait Islander people, including:
  • the health status of the population, including long-term health conditions experienced;
  • health risk factors, such as smoking, overweight/obesity, diet, exercise, alcohol consumption, substance use and family stressors;
  • use of health services such as consultations with health practitioners and actions people have recently taken for their health; and
  • demographic and socioeconomic characteristics.

46 A full list of data items from the survey is included in the Users' Guide.

47 The survey was developed in consultation with numerous stakeholders, including the representatives from Commonwealth and State/Territory government agencies, non-government organisations and relevant academic institutions.

48 More detailed results for the topics presented in this release, as well as other topics from the survey, are expected to be released on the ABS website in 2014.

DATA PROCESSING

49
A combination of clerical and computer-based systems were used to process data from the 2012-13 NATSIHS. The content of the data file was checked to identify unusual values which may have significantly altered estimates and also to assess illogical relationships not previously identified by edits. More information on data processing is provided in the Users' Guide.

WEIGHTING, BENCHMARKING AND ESTIMATION

Weighting

50
Weighting is the process of adjusting results from a sample survey to infer results for the total in-scope population. To do this, a 'weight' is allocated to each sample unit corresponding to the level at which population statistics are produced, e.g. person or household level. The weight can be considered an indication of how many population units are represented by the sample unit. For the 2012-13 NATSIHS, separate person and household weights were developed.

Selection weights

51
The first step in calculating weights for each person or household is to assign an initial weight, which is equal to the inverse of the probability of being selected in the survey. For example, if the probability of being selected in the survey was 1 in 45, then the person would have an initial weight of 45 (that is, they would represent 45 people).

52
After calculating the initial person weights, an adjustment was incorporated into the weighting to account for Aboriginal and Torres Strait Islander persons not covered by the sample. Paragraph 69 provides information on undercoverage. The initial household weights were also similarly adjusted.

Benchmarking

53
The person and household weights were separately calibrated to independent estimates of the population of interest, referred to as 'benchmarks'. Weights calibrated against population benchmarks ensure that the survey estimates conform to the independently estimated distributions of the population rather than to the distribution within the sample itself. Calibration to population benchmarks helps to compensate for over or under-enumeration of particular categories (e.g. age, sex, state), which may occur due to either the random nature of sampling, non-response, non-identification or various other undercoverage factors. This process can reduce the sampling error of estimates and may reduce the level of undercoverage bias. More information on undercoverage is provided in paragraph 69.

54
A standard approach in ABS household surveys is to calibrate to population benchmarks by state, part of state, age and sex. In terms of the effectiveness of 'correcting' for potential undercoverage bias, it is assumed that the characteristics being measured by the survey for the covered population are similar to the uncovered population within weighting classes, as determined by the benchmarking strategy. Where this assumption does not hold, biased estimates may result.

55
For this survey, person weights were simultaneously calibrated to the following population benchmarks:
  • state by remoteness area;
  • state by age by sex;
  • Torres Strait Islander status by Torres Strait Islander region by adult;
  • remoteness area by age by sex; and
  • state by community.

56
The survey was benchmarked to the estimated Aboriginal and Torres Strait Islander resident population living in private dwellings at 30 June, 2011. As people in non-private dwellings (e.g. hotels) are excluded from the scope of the survey, they have also been excluded from the survey benchmarks. Therefore, the 2012-13 NATSIHS estimates do not (and are not intended to) match estimates for the total resident Aboriginal and Torres Strait Islander population obtained from other sources.

57
While estimates shown in this release are based on person weights only, household weights were also derived by calibrating the household weights to align with the person-level benchmarks, as there are no available Aboriginal and Torres Strait Islander household benchmarks.

Estimation

58
Estimates of counts of persons are obtained by summing person weights of persons with the characteristic of interest. The estimates presented in this release are based on benchmarked person weights.

59
More information on weighting, benchmarking and estimation is provided in the Users' Guide.

RELIABILITY OF ESTIMATES

60
All sample surveys are subject to error which can be broadly categorised as either:
  • sampling error; or
  • non-sampling error.

61
Sampling error occurs because only a small proportion of the total population is used to produce estimates that represent the whole population. Sampling error can be reliably measured as it is calculated based on the scientific methods used to design surveys.

62
Non-sampling error may occur in any data collection, whether it is based on a sample or a full count (e.g. Census). Non-sampling error may occur at any stage throughout the survey process. For example, persons selected for the survey may not respond (non-response); survey questions may not be clearly understood by the respondent; responses may be incorrectly recorded by interviewers; or there may be errors in coding or processing survey data.

Sampling error

63
Sampling error is the expected random difference that could occur between the published estimates, derived from using a sample of persons, and the value that would have been produced if all persons in scope of the survey had been enumerated. A measure of the sampling error for a given sample estimate is provided by the standard error, which may be expressed as a percentage of the estimate (relative standard error).

64
In this release, estimates with relative standard errors (RSEs) of 25-50% and greater than 50% have been annotated. Estimates with RSEs of 25-50% should be used with caution and those with RSEs greater than 50% are considered too unreliable for most purposes.

Non-sampling error

65
Every effort was made to minimise other non-sampling error by:
  • careful design and testing of questionnaires;
  • intensive training of interviewers; and
  • extensive editing and quality control procedures at all stages of data processing.

66
An advantage of the Computer-Assisted Interview (CAI) used for this survey is that it potentially reduces non-sampling errors by enabling edits to be applied as the data are being collected. These edits allow the interviewer to query respondents and resolve issues during the interview. Sequencing of questions is also automated so that respondents are asked only relevant questions and only in the appropriate sequence, eliminating interviewer sequencing errors.

67
Analysis was also undertaken to compare the characteristics of respondents to the 2012-13 NATSIHS with a number of ABS collections to ascertain data consistency. Sources for comparison included:
  • 2011 Census of Population and Housing;
  • 2008 National Aboriginal and Torres Strait Islander Social Survey; and
  • 2004-05 and 2002 National Aboriginal and Torres Strait Islander Health Survey.

68
Further information on undercoverage and non-response is provided in the following paragraphs. More detailed information on non-sampling error is provided in the Users' Guide.

Undercoverage

69
Undercoverage is one potential source of non-sampling error and is the shortfall between the population represented by the achieved sample and the in-scope population. It can introduce bias into the survey estimates. However, the extent of any bias depends upon the magnitude of the undercoverage and the extent of the difference between the characteristics of those people in the coverage population and those of the in-scope population.

70
Undercoverage rates can be estimated by calculating the difference between the sum of the initial weights of the sample and the population count. If a survey has no undercoverage, then the sum of the initial weights of the sample would equal the population count (ignoring small variations due to sampling error). For more information on weighting refer to paragraph 50.

71
In the 2012-13 NATSIHS there was a relatively large level of undercoverage when compared to other ABS surveys. There was also an increase in undercoverage compared to previous ABS Aboriginal and Torres Strait Islander surveys. The overall 2012-13 NATSIHS coverage rate was approximately 38% of the in-scope population at the national level. The estimated coverage in the 2004-05 NATSIHS and the 2008 NATSISS was 58% and 47% respectively.

72
The overall undercoverage rate was approximately 62% of the population at the national level. This rate varies across states and territories, with Vic (72%), NSW and ACT (65% respectively) recording the highest rates of undercoverage compared with the lowest undercoverage rates in Tas (41%) and Qld (59%). Of the national rate, 6% is due to planned frame exclusions and overlap with the Monthly Population Survey where analysis has shown that the impact of any bias is minimal. More information on these exclusions is provided below.

73
Given the high undercoverage rate, the analysis undertaken to ensure that results from the 2012-13 NATSIHS were consistent with other data sources was more extensive than usual. Examples of the sources used for consistency checks are outlined in paragraph 67 and more information on the validation of survey data will be provided in the Users' Guide.

74
Briefly, potential bias due to undercoverage was addressed by the application of adjustments to the initial weights. Weights were calibrated to population benchmarks to account for the undercoverage at the various calibration levels.

75
More information on the measures taken to address potential bias will be provided in the Users' Guide.

76
Undercoverage may occur due to a number of factors, including:
  • frame exclusions (areas being removed from the sampling frame);
  • non-response;
  • non-identification as being of Aboriginal and/or Torres Strait Islander origin; and
  • issues arising in the field.

77
Each of these factors are outlined in more detail in the following paragraphs. To assist interpretation, a diagrammatical representation of the potential sources of undercoverage is denoted below.




Frame exclusions

78 Frame exclusions were incorporated into the 2012-13 NATSIHS to manage the cost of enumerating areas with a small number of Aboriginal and Torres Strait Islander persons.

79 At the national level it is estimated that 4% of the in-scope population was excluded from the frame. Part of this exclusion represents an estimate of the people who had moved since the 2011 Census. The number of people who moved may be higher than estimated and could account for a portion of the higher than expected non-identification estimate discussed in paragraph 85.

Non-response

80
Non-response may occur when people cannot or will not cooperate, or cannot be contacted. Unit and item non-response by persons/households selected in the survey can affect both sampling and non-sampling error. The loss of information on persons and/or households (unit non-response) and on particular questions (item non-response) reduces the effective sample and increases both sampling error and the likelihood of incurring response bias.

81
To reduce the level and impact of non-response, the following methods were adopted in this survey:
  • face-to-face interviews with respondents;
  • local Aboriginal and Torres Strait Islander facilitators were employed to assist with interviewing in communities;
  • follow-up of respondents if there was initially no response; and
  • ensuring the weighted file is representative of the population by aligning the estimates with population benchmarks.

82 In the 2012 -13 NATSIHS non-response accounts for a portion of overall undercoverage. The two components of non-response were:
  • non-response to the screening question; and
  • non-response to the survey after identification of an Aboriginal and Torres Strait Islander household.

83
Of the households screened in non-community areas, approximately 80% of households responded. Of households who responded to the screening question, approximately 2.6% were identified as having an Aboriginal and Torres Strait Islander usual resident. Of these identified households, around 74% then responded to the survey.

84 In discrete Aboriginal and Torres Strait Islander communities 77% of selected in-scope households responded to the survey.

Non-identification as being of Aboriginal and/or Torres Strait Islander origin

85
Non-identification of Aboriginal and Torres Strait Islander households during the screening process may have occurred due to:
  • Aboriginal and Torres Strait Islander people not identifying themselves as being of Aboriginal and/or Torres Strait Islander origin (passive refusals); or
  • the household spokesperson being unaware of (or unwilling to provide) the Indigenous status of other residents.

86
The under-identification of Aboriginal and Torres Strait Islander persons in non-community areas is estimated to be up to 31% of those screened. This estimate is the remaining level of undercoverage when all other known sources of undercoverage have been removed. Part of this proportion is likely to be due to other factors which are unknown.

Issues arising in the field


87
Known undercoverage, due to other issues arising in the field, included sample being excluded due to:
  • overlap with the Monthly Population Survey (MPS) and other select special social surveys;
  • occupational, health and safety issues; and
  • time constraints, particularly in Aboriginal and Torres Strait Islander communities and their associated out-stations.

88 The estimated undercoverage due to overlap with other ABS surveys was estimated to be 2.7% at the national level.

89 Of the 63 communities selected in the sample, 5 were not enumerated at all because of either occupational, health and safety concerns, closure of communities or lack of accommodation facilities in some locations. The overall coverage rate for Aboriginal and Torres Strait Islander communities was 49%. The Aboriginal and Torres Strait Islander community sample included households in the main community and their attached out-stations. Many of the communities selected did not have their associated out-stations enumerated. This was largely due to time constraints. The estimated coverage rate of the main community and out-stations was 52% and 13% respectively. Although the coverage of out-stations in the sample was quite low, it was estimated to make up 7.3% of the community population, and less than 1% of the total Aboriginal and Torres Strait Islander population. Consequently, this could potentially have a small impact to estimates.

Seasonal effects

90
The estimates in this publication are based on information collected from April 2012 to February 2013 and due to seasonal effects they may not be fully representative of other time periods in the year. For example, in the 2012-13 NATSIHS, people were asked about the number of times they had consulted with a health professional in the last 4 weeks prior to interview. Travel to access health care facilities, particularly in remote areas may be subject to seasonal variation throughout the year. Therefore, the results could have differed if the survey had been conducted over the whole year or in a different part of the year.

Interpretation of results

91
Care has been taken to ensure that the results of this survey are as accurate as possible. All interviews were conducted by trained ABS officers. Extensive reference material was developed for use and intensive training was provided to interviewers. There remain, however, other factors which may have affected the reliability of results, and for which no specific adjustments can be made. The following factors should be considered when interpreting these estimates:
  • Information recorded in this survey is 'as reported' by respondents, and therefore may differ from information available from other sources or collected using different methodologies. For example, information about medical conditions was self-reported and while not directly based on diagnosis by a medical practitioner in the survey, respondents were asked whether they had ever been told by a doctor or nurse that they had a particular health condition. Conditions which have a greater effect on people's wellbeing or lifestyle, or those which were specifically mentioned in the survey questions, are expected in general to have been better reported than others.
  • Results of previous surveys have shown a tendency for respondents to under-report alcohol consumption levels.
  • Responses may be affected by imperfect recall or individual interpretation of survey questions.
  • Some respondents may have provided responses that they felt were expected, rather than those that accurately reflected their own situation.

92
Every effort has been made to minimise such bias through the development and use of a culturally appropriate survey methodology.

93
For a number of survey data items, some respondents were unwilling or unable to provide the required information. Where responses for a particular data item were missing for a person or household they were recorded in a 'not known', 'not stated' or 'refusal' category for that data item. In some instances, 'not stated' categories have been included in the publication tables, to enable users to determine the suitability of the data for their purposes. In some instances, 'not stated' categories are not explicitly shown in the tables, but are included in the total or are grouped with another output category. These groupings are indicated by footnotes. Tables presenting proportions include 'not known' or 'not stated' categories in the calculation of these proportions.

94
Different data items were collected for different time periods, e.g. labour force status is based on the week prior to interview, and level of psychological distress relates to the four weeks prior to interview. The reliability and accuracy of data are therefore dependent on the respondent's recall.

95
Results of previous ABS surveys and administrative data collections on use of alcohol and illegal drugs suggest a tendency for respondents to under-report actual consumption levels.

96
The employment component of the 2012-13 NATSIHS is based on a reduced set of questions from the ABS monthly Labour Force Survey.

97 Broad information to assist the interpretation of specific topics in this publication is provided in the following paragraphs. Further information will be provided in the Users' Guide.

Social and emotional wellbeing


98 The 2012-13 NATSIHS contains a series of questions on social and emotional wellbeing in the four weeks prior to interview, based on selected items from a well-known survey instrument: The Kessler Psychological Distress Scale (K10).

99 The survey also contains questions related to personal stressors, discrimination, social support and cultural identification. Additional measures of wellbeing such as the mastery and control of one's life (Pearlin Mastery Scale) were also collected and are currently being assessed for data quality, with the intention for release in 2014.

100 The K10 is a widely used screening instrument, which gives a simple measure of psychological distress based on a person's emotional state during the four weeks prior to interview. It is not a diagnostic tool, but is an indicator of psychological distress. This survey collected responses to five of the K10 questions, producing outputs for what is referred to as the K5. This information on psychological distress (K5) is an important measure for understanding the social and emotional wellbeing of Aboriginal and Torres Strait Islander peoples, and can be used for comparison with the NHS and comparison over time.

101 Respondents were asked a series of five questions and for each item, they provided a five-level response scale, based on the amount of time they reported experiencing a particular feeling. Responses to the five questions were put together, resulting in a minimum possible score of 5 and a maximum possible score of 25. Low scores indicate low levels of psychological distress and high scores indicate high levels of psychological distress.

Comparability with other ABS data sources

102
To aid comparability with other ABS data sources, where possible, questions from existing surveys were used in the 2012 -13 NATSIHS. However, due to the number of topics included in this survey, it was not always possible to adopt the full question modules used in other surveys. In addition, some modules were further modified or omitted in remote areas because they were not relevant or not able to be effectively administered for the NATSIHS within these areas. Where possible, the 2012-13 NATSIHS used standard ABS 'shortened' question modules, designed to maximise comparability with the full question modules.

103
Results from the 2012-13 NATSIHS may differ from other ABS surveys which collect information on the same topics as the information is based on a sample of the population and are subject to sampling variability (or sampling error). For example, results from this survey may differ from the figures that would have been obtained from an enumeration of the entire population (e.g. Census).

104
Differences may also exist in the scope and/or coverage of this survey compared to other surveys. For example, the 2012-13 NATSIHS includes Aboriginal and Torres Strait Islander people living in private dwellings across Australia, including remote areas, whereas the 2011-12 National Health Survey includes people living in private dwellings across Australia, excluding very remote areas. Another example is the monthly Labour Force Survey, which includes people aged 15 years and over who live in private dwellings, but also includes a sample of people resident in non-private dwellings (e.g. hotels), which the 2012-13 NATSIHS does not include.

105
The collection period for this survey was April 2012 to February 2013. The results may therefore differ to other surveys conducted during different reference periods, due to seasonal effects. See paragraph 90 for more information.

106
Differences in estimates may also occur as a result of different collection methodologies. For example, if the information was:
  • collected through a personal interview;
  • self-enumerated by the respondent;
  • provided by the person themselves; or
  • was collected from a proxy.

107
Differences may also result from the context in which questions are asked (e.g. ordering of the questions or the type of survey being conducted). Additionally, self-identification of Aboriginal and Torres Strait Islander status may vary, depending on the collection methodology (e.g. face-to-face interview compared to a self-completed form).

Comparability with previous Aboriginal and Torres Strait Islander Surveys

108
The ABS previously conducted the National Aboriginal and Torres Strait Islander Health Survey (NATSIHS) in 2004-05. Also, the National Health Survey that was conducted in 2001 included an Aboriginal and Torres Strait Islander sample (known as the NHS(I)). Extensive information on the differences between the 2004-05 and 2001 surveys is provided in the Explanatory Notes of the National Aboriginal and Torres Strait Islander Health Survey, 2004-05 ( cat. no. 4715.0).

109 Understanding the extent to which data from the 2012-13 NATSIHS and the 2004-05 NATSIHS can be compared is essential to interpret apparent changes over time. The 2012-13 NATSIHS and the 2004-05 survey largely employ the same methodology and survey content for comparability purposes over time. A key difference in 2012-13, however, was the standardisation of Computer-Assisted Interviewing for all questions administered to respondents in remote and non-remote areas. In particular, non-remote participants were encouraged to record sensitive responses to questions about substance use on a computer themselves without field collectors viewing the screen. In 2004-05, substance use were recorded by non-remote participants on a separate form, which was perceived as a strategy to encourage more reliable reporting.

110 Between 2006 and 2011 the Aboriginal and Torres Strait Islander population increased by 30%, or 153,000 people. When comparing numbers from the 2012-13 AATSIHS with previous Aboriginal and Torres Strait Islander surveys, users should be aware of the large increase in Aboriginal and Torres Strait Islander population and consider the impact this may have when interpreting change over time.

111 A prompt card containing certain other long-term health conditions was incorrectly excluded from the 2012-13 National Aboriginal and Torres Strait Islander Health Survey (NATSIHS). This resulted in a small number of conditions not being prompted for, and primarily affects estimates for a number of mental health conditions. There is no effect on the other health conditions. Data on mental health conditions is therefore not comparable with the 2011-12 National Health Survey (NHS) and not available for release.

112
Further information on the comparability of the 2012-13 and 2004-05 NATSIHS will be provided in the Users' Guide.

113
This release contains selected data from the 2008 and 2002 NATSISSs. Data have been limited to items where there is a sufficient level of comparability between the surveys.

CLASSIFICATIONS

114
Long-term health conditions described in this publication are classified to a classification developed for use in the NHS (or variants of that classification), based on the International Classification of Diseases (ICD). The classification of data from the 2001, 2004-05, 2007-08 and 2011-12 surveys are based on the 10th revision of the ICD.

115 Descriptions for data items such as Body Mass Index and the Kessler Psychological Distress Scale ( K5) are included in the Glossary to this publication.

116 Geography data was classified according to the Australian Statistical Geographical Standard (ASGS), July 2011 (cat. no. 1270.0.55.001).

PRODUCTS AND SERVICES

117
Further Australian Aboriginal and Torres Strait Islander Health Survey (AATSIHS) publications are planned for release. Results from the National Aboriginal and Torres Strait Islander Nutrition and Physical Activity Survey (NATSINPAS) and the National Aboriginal and Torres Strait Islander Health Measurements Survey (NATSIHMS) will be released progressively throughout 2014. For more information, see 2012-13 Australian Aboriginal and Torres Strait Islander Health Survey: Release Schedule.

118
A copy of the survey questionnaire and prompt cards will be provided with the Users' Guide.

119
More detailed results for the topics presented in this release, as well as additional topics from the survey, are expected to be released on the ABS website in 2014.

120
To return the survey's information to Aboriginal and Torres Strait Islander people, a series of thematic releases are planned for distribution (in printed format) to Aboriginal and Torres Strait Islander communities, organisations and schools. Further information will be available on the ABS website.

121
Special tabulations based on the data from this survey are available on request. Subject to confidentiality and sampling variability constraints, tabulations can be produced from the survey to meet individual requirements. These can be provided in electronic or printed form.

122
For more information about this survey and associated products contact the National Information and Referral Service on 1300 135 070 or the National Centre for Aboriginal and Torres Strait Islander Statistics on 1800 633 216 or email indigenous.statistics@abs.gov.au.

ACKNOWLEDGMENTS

123
The 2012-13 NATSIHS was dependent on the high level of cooperation received from Aboriginal and Torres Strait Islander peoples and their communities. Without their continued cooperation, the wide range of Aboriginal and Torres Strait Islander statistics published by the ABS would not be available. Information received by the ABS is treated in strict confidence as required by the Census and Statistics Act 1905.

RELATED PUBLICATIONS

124
Other ABS publications which may be of interest are shown under the 'Related Information' tab of this release.

125 Current ABS publications and other products available from the ABS website include:

Life Tables for Aboriginal and Torres Strait Islander Australians, 2011 (cat. no. 3303.0.55.003
The Health and Welfare of Australia's Aboriginal and Torres Strait Islander Peoples, 2010 (cat. no. 4704.0)
National Aboriginal and Torres Strait Islander Health Survey, 2004-05 ( cat. no. 4715.0)
National Aboriginal and Torres Strait Islander Health Survey: Users' Guide, 2004-05 ( cat. no. 4715.0.55.004)
National Aboriginal and Torres Strait Islander Social Survey, 2002 (cat. no. 4714.0)
National Health Survey, Aboriginal and Torres Strait Islander Results, Australia, 2001 (cat. no. 4715.0)
National Health Survey: Users' Guide, 2001 (cat. no. 4363.0.55.001)
National Health Survey (Aboriginal and Torres Strait Islander people): Expanded Confidentialised Unit Record File, Information Paper, 2001 (cat. no. 4715.0.55.002)
Hospital Statistics, Aboriginal and Torres Strait Islander Australians, 1997-98 (cat. no. 4711.0)
National Health Survey: Aboriginal and Torres Strait Islander Results, Australia, 1995 (cat. no. 4806.0)
Cigarette Smoking among Aboriginal and Torres Strait Islander Australians, 1994 (cat. no. 4701.0)
Overweight and Obesity, Aboriginal and Torres Strait Islander Australians, 1994 (cat. no. 4702.0)
Self-Assessed Health Status, Aboriginal and Torres Strait Islander Australians, 1994 (cat. no. 4707.0)
Experimental Estimates and Projections, Aboriginal and Torres Strait Islander Australians, 1991 to 2009 (cat. no. 3238.0)