1 This publication contains summary results from the 2003 Survey of Disability, Ageing and Carers (SDAC) conducted throughout Australia during the period June to November 2003.
2 The aims of the survey were to:
3 The survey collected the following information from the three target populations:
- measure the prevalence of disability in Australia
- measure the need for support of older people and those with a disability
- provide a demographic and socio-economic profile of people with disabilities, older people and carers compared with the general population
- estimate the number of and provide information about people who provide care to older people and people with disabilities.
4 The survey also collected a small amount of information about other people.
- people with a disability - information about their long-term health conditions, need for and receipt of assistance, use of aids and equipment such as wheelchairs and hearing aids, and participation in community activities
- older people (i.e. those aged 60 years and over) - information about their need for, and receipt of assistance, and participation in community activities
- people who care for persons with a disability and older people - information about the type of care they provide, the support available to them, and the characteristics of carers and some effects that the caring role has on their lives.
SCOPE OF THE SURVEY
5 The survey covered people in both urban and rural areas in all states and territories, except for those living in remote and sparsely settled parts of Australia. The exclusion of these people will have only a minor impact on any aggregate estimates that are produced for individual states and territories, with the exception of the Northern Territory (NT) where they account for over 20% of the population. However, separate estimates have not been produced for the NT (see paragraph 31).
6 The survey included people in both private and non-private dwellings, including people in cared-accommodation establishments but excluding those in gaols and correctional institutions.
7 The scope of the survey was all persons except:
8 Coverage rules were applied which aimed to ensure that each person in scope was associated with only one dwelling and thus had only one chance of selection.
- visitors to private dwellings
- certain diplomatic personnel of overseas governments, customarily excluded from the Census and estimated resident population figures
- overseas residents in Australia
- members of non-Australian defence forces (and their dependants) stationed in Australia.
9 Usual residents of selected private dwellings were included in the survey unless they were away on the night of enumeration, and had been away or were likely to be away for four months or more. This was designed to avoid multiple selection of a person who might be spending time, for instance, in a nursing home, and be eligible for selection there.
10 Visitors to private dwellings were excluded as the expectation was that most would have their chance of selection at their usual residence.
11 Boarding school pupils were excluded from coverage but other persons in non-private dwellings in the scope of the survey were included if they had lived there, or were likely to live there, for four months or more.
12 Occupants of cared-accommodation establishments in the scope of the survey were included if they had been, or were expected to be, a usual resident of an establishment for three months or more.
13 Different data collection methods were used for the household component and the cared-accommodation component of this survey.
14 The household component covered people in:
15 Smaller disability group homes (with fewer than six people) were considered to be private dwellings.
- private dwellings such as houses, flats, home units, townhouses, tents and other structures used as private places of residence at the time of the survey
- non-private dwellings such as hotels, motels, boarding houses, educational and religious institutions, guest houses, construction camps, short-term caravan parks, youth camps and camping grounds, including staff quarters, and self-care components of retirement villages.
16 In this publication, people in the household component of the survey are referred to as 'living in households'.
17 The cared-accommodation component covered residents of hospitals, nursing homes, hostels and other homes such as children's homes, who had been, or were expected to be, living there or in another health establishment for three months or more.
18 Data for the household component of the survey were collected by trained interviewers, who conducted computer-assisted personal interviews.
19 A series of screening questions were asked of a responsible adult in a selected household to establish whether the household included:
20 Where possible, a personal interview was conducted with people identified in any of the above populations. Proxy interviews were conducted for children aged less than 15 years, those aged 15-17 years whose parents did not permit them to be personally interviewed, and those with a disability that prevented them from having a personal interview.
- people with a disability
- people aged 60 years and over
- people who were primary carers for people with a core-activity limitation, living either in the same household or elsewhere, or who provided any care to persons living elsewhere.
21 People with a disability were asked questions relating to help and assistance needed and received for self-care, mobility, communication, cognition or emotion, health care, housework, property maintenance, meal preparation, paperwork (reading and writing tasks) and transport activities. They were also asked questions relating to computer and Internet use and participation in community activities. Those aged 5-20 years (or their proxies) were asked about schooling restrictions, and those aged 15-64 years about employment restrictions.
22 People aged 60 years and over without a disability were asked questions about need for, and receipt of, help for housework, home maintenance, meal preparation, paperwork (reading and writing tasks) and transport activities. They were also asked questions relating to computer and Internet use and participation in community activities.
23 Primary carers of a person with a disability or older person were asked about the assistance they provided, the assistance they could call on, and their employment experience. They were also asked to complete a self-enumeration form which collected information about their attitudes to, and experience of, their caring role. This form was completed by the carer during the interview.
24 Basic demographic and socio-economic information was collected for all other people. Most of this information was provided by a responsible adult in the household, rather than by each person individually.
25 The cared-accommodation component was enumerated in two stages using a mail-based methodology directed to administrators of selected establishments.
26 The first stage required completion of a Contact Information Form to establish the name of a contact officer, the current number of occupants within the establishment and the type of establishment.
27 The second stage required the nominated contact officer to select occupants, following the instructions provided. A separate questionnaire was completed for each selected occupant meeting the coverage requirements.
28 The range of data collected in this component was smaller than in the household component as some topics were not suitable for collection through a mail-based methodology or were irrelevant to those residing in cared accommodation.
29 Multi-stage sampling techniques were used to select the sample for the survey. After sample loss, the household sample included approximately 14,000 private dwellings and 300 non-private dwelling units, while the cared accommodation sample included approximately 550 establishments.
30 After exclusions due to scope and coverage, the final sample comprised 36,241 people for the household component and 5,145 people for the cared-accommodation component.
31 The sample in the NT was reduced to a level such that NT records contributed appropriately to national estimates but could not support reliable estimates for the NT. This was done to enable a larger NT sample to be used in the General Social Survey conducted by the ABS in 2002. As a result, estimates for the NT are not shown separately in this publication.
WEIGHTING, BENCHMARKING AND ESTIMATION
32 Weighting is the process of adjusting results from a sample survey to infer results for the total population. To do this, a 'weight' is allocated to each sample unit. The weight is a value which indicates how many population units are represented by the sample unit.
33 The first step in calculating weights for each person was to assign an initial weight, which was equal to the inverse of the probability of being selected in the survey. For example, if the probability of a person being selected in the survey was 1 in 600, then the person would have an initial weight of 600 (that is, they represent 600 others).
34 The responses from persons in the cared-accommodation component and persons in the household component of the survey were weighted together in order to represent the entire Australian population.
35 The weights were calibrated to align with independent estimates of the population, referred to as 'benchmarks', in designated categories of sex by age group by area of usual residence. Weights calibrated against population benchmarks compensate for over or under-enumeration of particular categories of persons and ensure that the survey estimates conform to the independently estimated distribution of the population by age, sex and area of usual residence, rather than to the distribution within the sample itself.
36 The survey was benchmarked to the estimated population living in non-sparsely settled areas at 30 June 2003 based on results from the 2001 Census of Population and Housing.
37 It should be noted that separate benchmarks were not available for special dwellings. Consequently estimates for non-private dwellings may be less reliable than those for private dwellings.
38 Survey estimates of counts of persons are obtained by summing the weights of persons with the characteristic of interest. Estimates of non-person counts (e.g. days away from work) are obtained by multiplying the characteristic of interest with the weight of the reporting person and aggregating.
39 Totals presented in tables comparing rates over time are shown as age-standardised percentages. Age standardisation has been undertaken using the direct method (see Technical Note). An age-standardised rate is calculated to remove the effects of different age structures when comparing population groups or changes over time. A standard age composition is used, in this case the age composition of the 2003 SDAC. The standardised rate is that which would have prevailed if the actual population had the standard age composition. Age-specific disability rates are multiplied by the standard population for each age group. The results are added and the sum calculated as a percentage of the standard population total to give the age-standardised percentage rate. The standardised rates should only be used to identify differences between population groups and changes over time.
RELIABILITY OF ESTIMATES
40 The estimates provided in this publication are subject to sampling and non-sampling error.
41 Sampling error is the difference between the published estimates, derived from a sample of persons, and the value that would have been produced if all persons in scope of the survey had been included. For more information refer to the Technical Note.
42 Non-sampling error may occur in any collection, whether it is 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 of answers by interviewers, and errors in coding and processing data.
43 Non-response occurs when people cannot or will not cooperate, or cannot be contacted. Non-response can affect the reliability of results and can introduce a bias. The magnitude of any bias depends upon the rate of non-response and the extent of the difference between non-respondents' characteristics and those of people who responded to the survey.
44 The following methods were adopted to reduce the level and impact of non-response:
45 Every effort was made to reduce other non-sampling error to a minimum by careful design and testing of the questionnaire, training of interviewers and data entry staff, and extensive editing and quality control procedures at all stages of data processing.
- face-to-face interviews with respondents
- the use of interviewers who could speak languages other than English, where necessary
- follow-up of respondents if there was initially no response
- weighting to population benchmarks.
INTERPRETATION OF RESULTS
46 Disability is a difficult concept to measure because it depends on a respondent's perception of their ability to perform a range of activities associated with daily life. Factors discussed below should also be considered when interpreting the estimates contained in this publication.
47 Information in the survey was based, wherever possible, on the personal response given by the respondent. However, in cases where information was provided by another person, some answers may differ from those the selected person would have provided. In particular, interpretation of the concepts of 'need' and 'difficulty' may be affected by the proxy-interview method.
48 A number of people may not have reported certain conditions because of:
49 As certain conditions may not have been reported, data collected from the survey may have underestimated the number of people with one or more disabilities.
- the sensitive nature of the condition (e.g. alcohol and drug-related conditions, schizophrenia, mental retardation or mental degeneration)
- the episodic or seasonal nature of the condition (e.g. asthma, epilepsy)
- a lack of awareness of the presence of the condition on the part of the person reporting (e.g. mild diabetes) or a lack of knowledge or understanding of the correct medical terminology for their condition
- any lack of comprehensive medical information kept by their cared-accommodation establishment.
50 The need for help may have been underestimated, as some people may not have admitted needing help because of such things as a desire to remain independent, or may not have realised help was needed with a task because help had always been received with that task.
51 The criteria by which people assessed whether they had difficulty performing tasks may have varied. Comparisons may have been made with the ability of others of a similar age, or with the respondent's own ability when younger.
52 The different collection methods used - personal interview for households, and administrator completed forms for cared accommodation - may have had some effect on the reporting of need for assistance with core activities. As a result there may have been some impact on measures such as disability status. If so, this would have had more impact on the older age groupings because of their increased likelihood of being in aged-care accommodation.
MAKING COMPARISONS BETWEEN SURVEYS OVER TIME
53 Much of the content of the five disability surveys conducted by the ABS in 1981, 1988, 1993, 1998 and 2003 is comparable. There are differences, however, as later surveys have attempted to obtain better coverage of disability and of specific tasks and activities previously considered too sensitive for a population survey. For instance, the task of toileting was introduced in 1988 as part of the self-care activity. Three new screening questions were added in 1993, 'difficulty gripping', 'head injury, stroke or brain damage' and 'any other conditions', such as arthritis, Alzheimer's disease, asthma, heart disease or any other, which were restricting in any way. Changes to the 1998 and 2003 screening questions are discussed below. For the 2003 survey the inclusion of questions relating to unmet need for and receipt of assistance with cognition or emotion provides a better perspective on assistance needs and requirements for both physical and psychological needs.
Changes between surveys
Identification of disability population
54 Efforts to improve the criteria for identifying disability may have contributed to changes in the results between surveys before the 1998 SDAC. Changes made to the 1998 and 2003 SDAC disability screening questions, following consultation with user groups, include:
55 For the first time, in the household component of the 2003 SDAC, information was collected regarding access to computers and the Internet at home and elsewhere. New items relating to disability populations include:
- identifying a more restricted population with hearing loss (a full count of hearing impairment is still available)
- separately identifying people with chronic pain and breathing difficulties
- focusing the restriction qualifier used with a number of screening questions to refer to everyday activities
- changes to the need for and receipt of assistance by the inclusion of questions relating to the receipt of assistance with cognition or emotion.
56 There have been a number of changes made to the previously used SDAC output terminology to improve alignment with concepts and definitions used in the International Classification of Functioning, Disability and Health. They are:
- Whether used a computer or the Internet at home in last 12 months
- Purpose of use of computer or the Internet in last 12 months
- Where used computer or the Internet in last 12 months
- Activities performed using the Internet
- Need for and receipt of assistance with cognition or emotion.
Changes to classifications
57 In 2001, the ABS Classification of Qualifications (ABSCQ) (cat. no. 1262.0), was replaced by the Australian Standard Classification of Education (ASCED) (cat. no. 1272.0). The ASCED is a new national standard classification which can be applied to all sectors of the Australian education system including schools, vocational education and training, and higher education. It replaces a number of classifications previously used in administrative and statistical systems, including the ABSCQ. The ASCED comprises two classifications: Level of Education and Field of Education.
- 'core-activity restriction' is now referred to as 'core-activity limitation'
- 'specific restrictions' is now referred to as 'specific restrictions or limitations'
- 'restricting impairment' is now referred to as 'disability type'
- 'restricting-impairment group' is now referred to as 'disability group'.
58 Further information about SDAC will be included in Disability, Ageing and Carers: User Guide, Australia, 2003 (cat. no. 4431.0), expected to be released on the ABS web site in October 2004.
Results for states
59 A set of tables in a spreadsheet format equivalent to those in this publication will be produced for each state and the Australian Capital Territory (subject to standard error and confidentiality constraints and excluding time series tables) and Australia. These tables can be purchased from the ABS web site <www.abs.gov.au> or from the ABS upon request.
Secondary table sets
60 There will be some secondary table sets released, similar to tables contained in the two thematic publications released from the 1998 SDAC: Disability and Long Term Health Conditions (cat. no. 4433.0) and Caring in the Community (cat. no. 4436.0).
61 It is expected that a basic confidentialised unit record file available via CD-ROM and/or the Remote Access Data Laboratory will be produced from the SDAC, subject to the approval of the Australian Statistician.
62 As well as releasing publications and standard products, the ABS can make available special tabulations. Subject to confidentiality and standard error constraints, tabulations can be produced from the survey incorporating data items, populations and geographic areas selected to meet individual requirements. These can be provided in printed form, or in spreadsheets sent by email or on CD-ROM.
63 This publication's Summary of Findings, these Explanatory Notes, the media release and a list of data items included in the survey are available free of charge on the ABS web site <www.abs.gov.au>. Further information on the survey and associated products is available from the contact officer listed at the front of this publication.
64 ABS publications draw extensively on information provided freely by individuals, businesses, governments and other organisations. Their continued cooperation is very much appreciated; without it, the wide range of 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.
65 Previous ABS publications relating to disability, ageing and carers:
66 Other ABS publications which may be of interest include:
Disability, Australia: Preliminary, 2003 (cat. no. 4446.0)
Census of Population and Housing: Ageing in Australia, 2001 (cat. no. 2048.0)
Disability, Ageing and Carers, Australia: Summary of Findings, 1998 (cat. no. 4430.0)
Caring in the Community, 1998 (cat. no. 4436.0)
Disability, Ageing and Carers: User Guide, Australia, 1998 (cat. no. 4431.0)
Disability, Ageing and Carers, Australia: Disability and Long Term Health Conditions, 1998 (cat. no. 4433.0)
Focus on Families: Caring in Families: Support for Persons who are Older or have Disabilities, 1995 (cat. no. 4423.0)
Focus on Families: Family Life, 1995 (cat. no. 4425.0)
Disability, Ageing and Carers, Australia: Summary of Findings, 1993 (cat. no. 4430.0)
Disability, Ageing and Carers, Australia: Disability and Disabling Conditions, 1993 (cat. no. 4433.0)
Disability, Ageing and Carers, Australia: Visual Impairment, 1993 (cat. no. 4434.0)
Disability, Ageing and Carers, Australia: Hearing Impairment, 1993 (cat. no. 4435.0)
Disability, Ageing and Carers, Australia: Brain Injury and Stroke, 1993 (cat. no. 4437.0)
67 Current publications produced by the ABS are listed in the Catalogue of Publications and Products (cat. no. 1101. 0). The ABS also issues, on Tuesdays and Fridays, a Release Advice (cat. no. 1105.0) which lists publications to be released in the next few days. The Catalogue and Release Advice are available on the ABS web site at <www.abs.gov.au> or from any ABS office.
Australian Social Trends, 2004 (cat. no. 4102.0)
General Social Survey: Summary Results, Australia, 2002 (cat. no. 4159.0)
National Aboriginal and Torres Strait Islander Social Survey, 2002 (cat. no. 4714.0)
National Health Survey: Summary of Results, 2001 (cat. no. 4364.0)
Education and Training Experience, Australia, 2001 (cat. no. 6278.0)
Private Hospitals, Australia, 2000-2001 (cat. no. 4390.0)
Income Distribution, Australia, 1999-2000 (cat. no. 6523.0)
Older People, Australia: A Social Report, 1999 (cat. no. 4109.0)
Children, Australia: A Social Report, 1999 (cat. no. 4119.0)
How Australians Use Their Time, 1997 (cat. no. 4153.0)
Labour Force, Australia (cat. no. 6203.0)