Microdata and TableBuilder: Australian Aboriginal and Torres Strait Islander Health Survey, Nutrition and Physical Activity

This publication presents information about the Australian Aboriginal and Torres Strait Islander Health Survey (AATSIHS) conducted by the Australian Bureau of Statistics (ABS) in 2012-13. Specifically, it contains information that presents microdata from the National Aboriginal and Torres Strait Islander Nutrition and Physical Activity Survey (NATSINPAS), 2012-13 component of the Australian Aboriginal and Torres Strait Islander Health Survey in the form of a TableBuilder dataset, and Basic and Expanded Confidentialised Unit Record Files (CURFs). The CURFs also include biomedical information from the National Aboriginal and Torres Strait Islander Health Measures Survey (NATSIHMS) component of the AATSIHS for NATSINPAS respondents who agreed to participate.

The aim of this publication is to assist users of the microdata to better understand both the nature of the survey and its potential and shortcomings in meeting their data needs. A list of output data items currently available for the TableBuilder, Basic CURF and Expanded CURF can be found in the Downloads tab of this publication.

Information about the design and conduct of the Australian Aboriginal and Torres Strait Islander Health Survey can be found in Australian Aboriginal and Torres Strait Islander Health Survey: Users’ Guide (cat. no. 4727.0.55.002).

The following microdata products are currently available from this survey:

• TableBuilder is an online tool for creating tables and graphs and can be accessed via the ABS website.
• Basic CURF allows approved users access to data in their own environment (via a CD-ROM), as well as via the Remote Access Data Laboratory (RADL) and the DataLab.
• Expanded CURF allows approved users access to data in the RADL and the DataLab environments.

To apply for access to microdata products, follow the instructions via the Microdata Entry Page.

For more information on the products available from the AATSIHS and the associated Australian Health Survey (AHS), see the Release Schedule pages in the Australian Aboriginal and Torres Strait Islander Health Survey: Users' Guide (cat. no. 4727.0.55.002) and the Australian Health Survey: Users' Guide (cat. no. 4363.0.55.001).

Further information about the survey and the microdata products can be found in this product:

• a detailed list of data items for the TableBuilder and CURFs are available in the Data Downloads section
• the Quality Declaration can be found in the Quality Declaration section.

For support in the use of microdata, please contact Microdata Access Strategies on 02 6252 7714 or via microdata.access@abs.gov.au.

Data obtained in the survey but not presented in the microdata may be available by request from the ABS as statistics in tabulated form.

Subject to confidentiality and sampling variability constraints, special tabulations can be produced incorporating data items, populations and geographic areas selected to meet individual requirements. These are available on request, on a fee for service basis. Contact the National Information and Referral Service on 1300 135 070 or client.services@abs.gov.au for further information. The ABS Privacy Policy outlines how the ABS will handle any personal information that you provide to us.

Information from the National Aboriginal and Torres Strait Islander Nutrition and Physical Activity Survey (NATSINPAS) is stored electronically in the form of data items. In some cases items were formed directly from individual survey questions, while in others, items were derived from answers to several questions (e.g. Body Mass Index derived from measured height and weight). Some items were derived with reference to information from other organisations such as the Department of Health (e.g. in relation to guidelines on time undertaking physical activity per week).

The following table shows the levels available in each NATSINPAS microdata product and examples of the information that are contained on those levels. For information on the data items and related output categories available on the TableBuilder or CURF products, refer to the data item list applicable to the specific product, which are available in Excel spreadsheet format from the Data downloads section of this product. 

Datasets from the Australian Aboriginal and Torres Strait Islander Health Survey are hierarchical in nature. A hierarchical data file is an efficient means of storing and retrieving information which describes one to many, or many to many, relationships (e.g. children 5-17 years may report multiple days on which they participated in physical activity and also multiple types of activities on each of these days). For information on the structure of individual microdata products, see Using the TableBuilder, Using the Basic CURF and Using the Expanded CURF pages within this product.

Instructions on how to use TableBuilder can be found in the User Manual: TableBuilder (cat. no. 1406.0.55.005) and via the help links within the product itself.

For support in the use of TableBuilder and analysis of the data generated from the TableBuilder, please contact Microdata Access Strategies on 02 6252 7714 or via microdata.access@abs.gov.au.

For confidentiality and/or usability reasons, some data item values have been collapsed and/or restricted for use on the TableBuilder.

As discussed on the File Structure section of this product, this survey is hierarchical in nature. For the TableBuilder the following structure is in place:

Some items were only collected in non-remote areas or remote areas. Data items are identified in the Data item list (located in the Data downloads section of this product) for which remoteness area they were collected in and users should ensure they reference this to ensure the population they are presenting is correct.

Additionally, the sample for the NATSINPAS was based on achieving reliable national non-remote and remote estimates. Therefore care should be taken when interpreting State/Territory estimates, particularly in States/Territories with smaller sample sizes. For details on sample sizes, reference should be made to the Response rates and Appendix 1: Sample Counts and Estimates pages located in the Australian Aboriginal and Torres Strait Islander Survey: Users' Guide (cat. not. 4727.0.55.002).

Some continuous data items are allocated special codes for certain responses (e.g. 9999 = 'Not applicable'). When creating ranges for such continuous items for use in the TableBuilder, these special codes will NOT be included in these ranges (any special codes for continuous (summation) data items are listed in the Data Item List and will be found in the categorical version of the continuous item. However, note that labelling of 0s in the DIL does not necessarily mean they are excluded from the ranges (for example - identifying 0 as 'Did not visit' or 'Did not do') as they may still be important in some calculations. Reference should be made to the categorical version of the item to identify which codes are specifically excluded). Therefore the total shown only represents 'valid responses' of that continuous data item rather than all responses (including special codes).

For example:

Systolic Blood Pressure is located both in the Person level folder...

...and the Person level folder under Summation Options.

The following table shows the responses for 'Systolic Blood Pressure' by 'Sex of person' using the version in the Person folder. The continuous values of the data item are contained in the 'A valid response was recorded' row. If the actual continuous values are to be displayed then it is necessary to use the Summation Option version and create a range for them.

Here is the same table with a range applied for the continuous values of 'Systolic Blood Pressure (mmHG)' (called Systolic Blood Pressure). Note that the numbers of respondents for the other responses 'Not applicable', 'Valid reading not obtained' and 'Not measured' no longer contribute to the table.

Any special codes for continuous data items are listed in the Data Item List.

Continuous items can be used to create custom categories in 'My Custom Data' by first ranging the item. For example, to create five year age groupings for 'Age first told had diabetes or high sugar levels' this can be done by ranging the item with a five year increments from Summation Options. However to deviate from groupings of equal increments, this must be done in 'My Custom Data'. As age is a continuous item, for deviations from equal increments, it must first be ranged (for example in one year increments) and then this ranged item can be grouped under the 'My Custom Data' tab to form unique age categories. For more information see the 'My Custom Data' section of the User Manual: TableBuilder (cat. no. 1406.0.55.005).

In accordance with the Census and Statistics Act 1905, all the data in TableBuilder are subjected to a confidentiality process before release. This confidentiality process is undertaken to avoid releasing information that may allow the identification of particular individuals, families, households, dwellings or businesses.

Processes used in TableBuilder to confidentialise records include the following:

• perturbation of data
• table suppression
• field exclusion groups

Perturbation effects

To minimise the risk of identifying individuals in aggregate statistics, a technique is used to randomly adjust cell values. This technique is called perturbation. Perturbation involves small random adjustments of the statistics and is considered the most satisfactory technique for avoiding the release of identifiable statistics while maximising the range of information that can be released. These adjustments have a negligible impact on the underlying pattern of the statistics.

The introduction of these random adjustments result in tables not adding up. While some datasets apply a technique called additivity to give internally consistent results, additivity has not been implemented on this TableBuilder. As a result, randomly adjusted individual cells will be consistent across tables, but the totals in any table will not be the sum of the individual cell values. The size of the difference between summed cells and the relevant total will generally be very small.

Please be aware that the effects of perturbing the data may result in components being larger than their totals. This includes determining proportions.

Table suppression

Some tables generated within TableBuilder may contain a substantial proportion of very low counts within cells (excluding cells that have counts of zero). When this occurs, all values within the table are suppressed in order to preserve confidentiality. The following error message below is displayed at the bottom of the table when table suppression has occurred.

ERROR: The table has been suppressed as it is too sparse
ERROR: table cell values have been suppressed

Field exclusion rules

Certain groups of similar variables are restricted from being used together in a table. These restrictions are referred to as field exclusion rules, and are in place in order to protect confidentiality. The collections of similar variables restricted in this way are called field exclusion groups.

For the Australian Aboriginal and Torres Strait Islander Health Survey there is one field exclusion group. This consists of the 2011 geographical and Socio-Economic Indexes for Areas (SEIFA) data items (see below for items).

Only one data item from this group may be used in a single table.

The geographic exception to this is the State or Territory item, which can be used in addition to one item from this group.

Items included in the field exclusion group are:

2011 Geographic Items

• Remoteness area categories ASGS 2011
• Greater Capital City Statistical Areas ASGS 2011
• Section of state ASGS 2011
• Primary Health Network 2011

2011 SEIFA Items

• Index of Economic Resources - 2011 - SA1 - Deciles - National
• Index of Economic Resources - 2011 - SA1 - Deciles - State
• Index of Economic Resources - 2011 - SA2 - Deciles - National
• Index of Economic Resources - 2011 - SA2 - Deciles - State
• Index of Education and Occupation - 2011 - SA1 - Deciles - National
• Index of Education and Occupation - 2011 - SA1 - Deciles - State
• Index of Education and Occupation - 2011 - SA2 - Deciles - National
• Index of Education and Occupation - 2011 - SA2 - Deciles - State
• Index of Relative Socio-economic Advantage and Disadvantage - 2011 - SA1 - Deciles - National
• Index of Relative Socio-economic Advantage and Disadvantage - 2011 - SA1 - Deciles - State
• Index of Relative Socio-economic Advantage and Disadvantage - 2011 - SA2 - Deciles - National
• Index of Relative Socio-economic Advantage and Disadvantage - 2011 - SA2 - Deciles - State
• Index of Relative Socio-economic Disadvantage - 2011 - SA1 - Deciles - National
• Index of Relative Socio-economic Disadvantage - 2011 - SA1 - Deciles - State
• Index of Relative Socio-economic Disadvantage - 2011 - SA2 - Deciles - National
• Index of Relative Socio-economic Disadvantage - 2011 - SA2 - Deciles - State

There is one weight variable visible on the TableBuilder file - Persons (Benchmarked weight) - and is located on the Person level under the Summation Options category. This weight has been benchmarked to produce Australian population estimates.

Using weights

The NATSINPAS is a sample survey. To produce estimates for the in-scope population you must use weight fields in your tables. With only one weight available for use, TableBuilder will apply 'Persons (Benchmarked weight)' by default.

Means, medians and sums of continuous data items are calculated at the level of the continuous data item. A weight is automatically applied from a weight allocated behind the scenes to the level of the variable. Due to current functionality of the software, a weight from another level cannot be brought into such calculations. The "subject" of means, medians and sums calculated in TableBuilder is therefore the statistical unit associated with the level of the database on which the continuous data item is stored. For example, the mean of the "Total minutes spent doing physical activity type that day (5-17)" data item at the Child 5-17 Years Physical Activity Detailed level (NR Only) would give the mean total minutes of physical activity by physical activity type and across 3 days while the mean of the "Total minutes doing mod to vig physical activity that day" at the Child 5-17 Years Physical Activity Detailed level (NR Only) would give the mean total minutes for physical activity across 3 days.

The weights used for these calculations are not visible, other than on the Person level, but are referenced in the 'Weighted by' statement with continuous variables, as per:

Where items are available on more than one level, an additional number is added to the label to indicate the level version. For example a (1) indicates it's a Household level version, a (2) indicates a Persons in household level version, a (3) indicates a Person level version, and so on. These are identified in the Data item list labelling as well as the item in TableBuilder. The numbering is based on the ordering of levels found in the File structure section of this product.

Care should be used to ensure the correct version of the item is used, particularly with regards to demographic items located on both the Persons in household and Person levels. See below for more details.

The Persons in Household level contains data for every person in the household while the Persons level only contains data for the selected persons. Both levels are children of the Household level - that is, they are siblings and are not linked by person but by household (see the File structure section of this product for further information on structure). This means that there is a many-to-many link between records at these levels (persons on the Person level are linked to all the people in their household on the Persons in household level). When summing the Person weight (which is stored at the Person level) the meaning of the estimates produced when disaggregating by another data item at the Person level will not be the same as the meaning of the estimates produced when disaggregating by a data item at the Persons in Household level. For example, disaggregating by Sex and Marital status at the Person level will produce estimates of the type "Number of persons who are Male and Married". These estimates will be additive (aside from the effects of perturbation) as shown below.

On the other hand, disaggregating by Sex and Marital status at the Persons in Household level, and using the Persons (Benchmarked weight) from the Person level, will produce estimates of the type "Number of persons in households containing one or more persons who are Male and Married". These estimates will usually not be additive, as shown below.

The Aboriginal and Torres Strait Islander Health Survey, Nutrition and Physical Activity 2012–13 Basic CURF contains unit records relating to all of the survey respondents who participated in the National Aboriginal and Torres Strait Islander Nutrition and Physical Activity Survey (NATSINPAS). The data are released under the Census and Statistics Act 1905, which has provision for the release of data in the form of unit records where the information is not likely to enable the identification of a particular person or organisation. Accordingly, there are no names or addresses of survey respondents on the CURF and other steps, including the following list of actions, have been taken to protect the confidentiality of respondents:

• the level of detail of many data items has been reduced by grouping, ranging or top coding values
• some unusual records have been changed to protect against identification
• excluding some data items that were collected
• household income data has been perturbed. In addition, the household income deciles have been applied using the cut-offs produced by data from the Australian Health Survey (AHS) CURF files, with an additional CPI adjustment made.

The nature of the changes made, and the relatively small number of records involved ensure that the effects on data for analysis purposes is considered negligible.

The changes mean that estimates produced from the CURF may differ from those published in Australian Aboriginal and Torres Strait Islander Health Survey: Physical Activity (cat. no. 4727.0.55.004), Australian Aboriginal and Torres Strait Islander Health Survey: Nutrition Results - Food and Nutrients (cat. no. 4727.0.55.005) or subsequent NATSINPAS-related publications.

Detailed information about the data collected, comments regarding data quality and other points to assist in using and interpreting the data are contained in Australian Aboriginal and Torres Strait Islander Health Survey: Users’ Guide (cat. no. 4727.0.55.002).

The structure of the files for this CURF is:

Due to the small sample size of the NATSINPAS (4,109 respondents), this CURF has been limited in geography to broad national Non-remote/Remote geography and the Socio-economic Index of Relative Disadvantage (SEIFA - deciles). This survey was designed to support non-remote/remote geographic estimates, and therefore does not support estimates for all states/territories or state by remoteness combinations that are available from other Aboriginal and Torres Strait Islander population surveys. However, for users interested in Nutrition and Physical Activity data that is suitable for State/Territory release, this geography is available via the associated TableBuilder dataset. For further information, please refer to the Using the TableBuilder section located in this product.

Some data were only collected in non-remote areas or remote areas, such as Physical activity. Data items are identified in the Data item list for which remoteness area they were collected in and users should ensure they reference this to ensure the population they are representing is correct.

Weights and hierarchical files

Weight variables

There are two weight variables on the Basic CURF file:

Person Weight PAA (IPAFINWT) - Person level - Benchmarked to the total population. This weight is located on the Person level.

Biomedical Weight PAA (IHMSPERW) - Biomedical level - Benchmarked to the total population aged 18 years and over. This weight is located on the Biomedical level. Note that the biomedical level also contains non-biomedical participant records, however, their biomedical weight is set to 0 so they won't contribute to weighted estimates. When using biomedical variables in conjunction with other variables on the biomedical level or with variables from other levels, the biomedical weight should be used.

There are no weights associated with the Household level. Household variables can be used in conjunction with the Person or Biomedical weights to provide, for example, geographic or household compositional information for selected persons. There are also no weights associated with the other topical levels. This is because the records are repeated for each person who was selected in the survey. If, for example, IPAFINWT is merged onto the Conditions level, it will be attached to each condition record and therefore be repeated for each person where they have more than one condition. This should be considered when producing tables. See Copying Information Across Levels below for more information.

For more information about weights, see Reliability of Estimates below.

Using weights

The NATSINPAS is a sample survey. To produce estimates for the in-scope population you must use weight fields in your calculations. The 'Biomedical Weight PAA' must be used for all tables where a biomedical level data item is being used. This includes where biomedical items are being used with items from other levels. Which weight, if any, is used on data located on non-benchmarked levels will affect the result as shown in the examples below:

Every record on each level of the file is uniquely identified.

The identifiers ABSHID, ABSGID, ABSCID, ABSTID, ABSKID, ABSDID, ABSUID, ABSEID, ABSBID, ABSFID and ABSSID appear on all levels of the file. Where the information for the identifier is not relevant for a level, it has a value of 0. See below for details on which IDs are relevant for which levels.

Each household has a unique thirteen digit random identifier, ABSHID. This identifier appears on the household level and is repeated on each level on each record pertaining to that household. The combination of identifiers uniquely identifies a record at a particular level as shown below:

1. Household = ABSHID
2. Person = ABSHID, ABSGID
3. Conditions = ABSHID, ABSGID, ABSCID
4. Child 2-4 years Physical Activity (NR Only) = ABSHID, ABSGID, ABSTID
5. Child 5-17 years Physical Activity (NR Only) = ABSHID, ABSGID, ABSKID
6. Child 5-17 years Physical Activity detailed (NR Only) = ABSHID, ABSGID, ABSKID, ABSDID
7. Adult Physical Activity (NR Only) = ABSHID, ABSGID, ABSUID
8. Pedometer (NR Only) = ABSHID, ABSGID, ABSEID,
9. Biomedical = ABSHID, ABSGID, ABSBID
10. Food = ABSHID, ABSGID, ABSFID
11. Supplements = ABSHID, ABSGID, ABSSID
12. ADG = ABSHID, ABSGID, ABSLFID

ABSHID assists with linking together people of the same household and also with household characteristics such as geography (located on the household level). The combination of ABSHID, ABSGID and ABSCID identifies each individual condition record a person has. When merging data with a level above, only those identifiers relevant to the level above are required. However, when merging, for example, the conditions level with the person level, the data on the person level will duplicate for each condition. See Copying Information Across Levels below for more information.

For information regarding whether a level is higher or lower than another, refer to the structure picture located in the About the Basic CURF section located above.

As the survey was conducted on a sample of private households in Australia, it is important to take account of the method of sample selection when deriving estimates from the CURF. This is particularly important as a person's chance of selection in the survey varied depending on the state or territory in which the person lived. If these chances of selection are not accounted for, by use of appropriate weights, the results will be biased. For details on the weighting process, see Weighting, Benchmarks and Estimation procedures in Australian Aboriginal and Torres Strait Islander Health Survey: Users' Guide (cat. no. 4727.0.55.002).

Each person record has a main weight (IPAFINWT). This weight indicates how many population units are represented by the sample units. When producing estimates of sub-populations from the CURF, it is essential that they are calculated by adding the weights of persons in each category and not just by counting the sample number in each category. If each person's weight were to be ignored when analysing the data to draw inferences about the population, then no account would be taken of a person's chance of selection or of different response rates across population groups, with the result that the estimates produced could be biased. The application of weights ensures that estimates will conform to an independently estimated distribution of the population by age, by sex, etc. rather than to the distributions within the sample itself.

Each person record on the CURF contains 250 replicate weights in addition to the main weight. Replicate weights can be used to calculate measures of sampling error. For details on sampling error calculations and replicate weights, see the Technical Note in the Australian Aboriginal and Torres Strait Islander Health Survey: Users' Guide (cat. no. 4727.0.55.002).

The Aboriginal and Torres Strait Islander Health Survey, Nutrition and Physical Activity 2012–13 Expanded CURF contains unit records relating to all of the survey respondents who participated in the National Aboriginal and Torres Strait Islander Nutrition and Physical Activity Survey (NATSINPAS). The data are released under the Census and Statistics Act 1905, which has provision for the release of data in the form of unit records where the information is not likely to enable the identification of a particular person or organisation. Accordingly, there are no names or addresses of survey respondents on the CURF and other steps, including the following list of actions, have been taken to protect the confidentiality of respondents:

• the level of detail of many data items has been reduced by grouping, ranging or top coding values
• some unusual records have been changed to protect against identification
• excluding some data items that were collected
• household income data has been perturbed. In addition, the household income deciles have been applied using the cut-offs produced by data from the Australian Health Survey (AHS) Expanded CURF files, with an additional CPI adjustment made.

The nature of the changes made, and the relatively small number of records involved ensure that the effects on data for analysis purposes is considered negligible.

The changes mean that estimates produced from the CURF may differ from those published in Australian Aboriginal and Torres Strait Islander Health Survey: Physical Activity (cat. no. 4727.0.55.004), Australian Aboriginal and Torres Strait Islander Health Survey: Nutrition Results - Food and Nutrients (cat. no. 4727.0.55.005) or subsequent NATSINPAS-related publications.

Detailed information about the data collected, comments regarding data quality and other points to assist in using and interpreting the data are contained in Australian Aboriginal and Torres Strait Islander Health Survey: Users’ Guide (cat. no. 4727.0.55.002).

The structure of the files for this CURF is:

Due to the small sample size of the NATSINPAS (4,109 respondents), this CURF has been limited in geography to broad national Non-remote/Remote geography and the Socio-economic Index of Relative Disadvantage (SEIFA - deciles). This survey was designed to support non-remote/remote geographic estimates, and therefore does not support estimates for all states/territories or state by remoteness combinations that are available from other Aboriginal and Torres Strait Islander population surveys. However, for users interested in Nutrition and Physical Activity data that is suitable for State/Territory release, this geography is available via the associated TableBuilder dataset. For further information, please refer to the Using the TableBuilder section located in this product.

Some data were only collected in non-remote areas or remote areas, such as Physical activity. Data items are identified in the Data item list for which remoteness area they were collected in and users should ensure they reference this to ensure the population they are representing is correct.

Expanded CURFs can only be accessed via the Remote Access Data Laboratory (RADL). Users must have applied for use of the RADL prior to using the Expanded CURF microdata. Details on the RADL can be found on the Microdata Entry Page.

Weights and hierarchical files

Weight variables

There are two weight variables on the Expanded CURF file:

Person Weight PAA (IPAFINWT) - Person level - Benchmarked to the total population. This weight is located on the Person level.

Biomedical Weight PAA (IHMSPERW) - Biomedical level - Benchmarked to the total population aged 18 years and over. This weight is located on the Biomedical level. Note that the biomedical level also contains non-biomedical participant records however their biomedical weight is set to 0 so they won't contribute to weighted estimates. When using biomedical variables in conjunction with other variables on the biomedical level or with variables from other levels, the biomedical weight should be used.

There are no weights associated with the Household or Persons in household level. Household variables can be used in conjunction with the Person or Biomedical weights to provide, for example, geographic or household compositional information for selected persons. The Persons in household level is available in order to produce additional compositional information about the household (e.g. Number of persons in household aged 4-14 years) which can be used with the person weight to represent the number of people living in households that contain at least two persons aged 4-14 years.

There are also no weights associated with the other topical levels. This is because the records are repeated for each person who was selected in the survey. If, for example, IPAFINWT is merged onto the Conditions level, it will be attached to each condition record and therefore be repeated for each person where they have more than one condition. This should be considered when producing tables. See Copying Information Across Levels below for more information.

For more information about weights, see Reliability of Estimates below.

Using weights

The NATSINPAS is a sample survey. To produce estimates for the in-scope population you must use weight fields in your calculations. The 'Biomedical Weight PAA' must be used for all tables where a biomedical level data item is being used. This includes where biomedical items are being used with items from other levels. Which weight, if any, is used on data located on non-benchmarked levels will affect the result as shown in the examples below:

Every record on each level of the file is uniquely identified.

The identifiers ABSHID, ABSAID, ABSGID, ABSCID, ABSTID, ABSKID, ABSDID, ABSUID, ABSEID, ABSBID, ABSFID, ABSSID and ABSLFID appear on all levels of the file. Where the information for the identifier is not relevant for a level, it has a value of 0. See below for details on which IDs are relevant for which levels.

Each household has a unique thirteen digit random identifier, ABSHID. This identifier appears on the household level and is repeated on each level on each record pertaining to that household. The combination of identifiers uniquely identifies a record at a particular level as shown below:

1. Household = ABSHID
2. Persons in Household = ABSHID, ABSAID
3. Person = ABSHID, ABSAID, ABSGID,
4. Conditions = ABSHID, ABSAID, ABSGID, ABSCID
5. Child 2-4 years Physical Activity (NR Only) = ABSHID, ABSAID, ABSGID, ABSTID
6. Child 5-17 years Physical Activity (NR Only) = ABSHID, ABSAID, ABSGID, ABSKID
7. Child 5-17 years Physical Activity detailed (NR Only) = ABSHID, ABSAID, ABSGID, ABSKID, ABSDID
8. Adult Physical Activity (NR Only) = ABSHID, ABSAID, ABSGID, ABSUID
9. Pedometer (NR Only) = ABSHID, ABSAID, ABSGID, ABSEID,
10. Biomedical = ABSHID, ABSAID, ABSGID, ABSBID
11. Food = ABSHID, ABSAID, ABSGID, ABSFID
12. Supplements = ABSHID, ABSAID, ABSGID, ABSSID
13. ADG = ABSHID, ABSAID, ABSGID, ABSLFID

ABSHID assists with linking together people of the same household and also with household characteristics such as geography (located on the household level). The combination of ABSHID, ABSGID and ABSCID identifies each individual condition record a person has. When merging data with a level above, only those identifiers relevant to the level above are required. However, when merging, for example, the conditions level with the person level, the data on the person level will duplicate for each condition. See Copying Information Across Levels below for more information.

For information regarding whether a level is higher or lower than another, refer to the structure picture located in the About the Expanded CURF section located above.

As the survey was conducted on a sample of private households in Australia, it is important to take account of the method of sample selection when deriving estimates from the CURF. This is particularly important as a person's chance of selection in the survey varied depending on the state or territory in which the person lived. If these chances of selection are not accounted for by use of appropriate weights, the results will be biased. For details on the weighting process, see Weighting, Benchmarks and Estimation procedures in Australian Aboriginal and Torres Strait Islander Health Survey: Users' Guide (cat. no. 4727.0.55.002).

Each person record has a main weight (IPAFINWT). This weight indicates how many population units are represented by the sample units. When producing estimates of sub-populations from the CURF, it is essential that they are calculated by adding the weights of persons in each category and not just by counting the sample number in each category. If each person's weight were to be ignored when analysing the data to draw inferences about the population, then no account would be taken of a person's chance of selection or of different response rates across population groups, with the result that the estimates produced could be biased. The application of weights ensures that estimates will conform to an independently estimated distribution of the population by age, by sex, etc. rather than to the distributions within the sample itself.

Each person record on the CURF contains 250 replicate weights in addition to the main weight. Replicate weights can be used to calculate measures of sampling error. For details on sampling error calculations and replicate weights, see the Technical Note in the Australian Aboriginal and Torres Strait Islander Health Survey: Users' Guide (cat. no. 4727.0.55.002).

The National Aboriginal and Torres Strait Islander Nutrition and Physical Activity Survey (NATSINPAS) 2012-13 collected information using household and personal questionnaires. Users intending to purchase the microdata should ensure that the data they require and the level of detail they need are available in the products. Complete lists of all data items included on the TableBuilder dataset, the Basic CURF and Expanded CURF, including relevant population and classification details, are available in the Data downlaods section of this product.

Each sheet of the data item lists indicates a level of data (e.g. Household level, Person level, Food level, Adult physical activity level) or a grouping of like data about a selected person (e.g. Demographics, Education, Risk factors - nutrition, Physical measures and body mass).

Definitions for data item concepts can be found in the topic pages of the Australian Aboriginal and Torres Strait Islander Health Survey: Users' Guide (cat. no. 4727.0.55.002).

For confidentiality and/or usability reasons some data item values have been collapsed and/or restricted for use on the Basic and Expanded CURFs. Additionally, data may be further masked to prevent identification of individual persons.

The Census and Statistics Act 1905 includes a legislative guarantee to respondents that their confidentiality will be protected. This is fundamental to the trust the Australian public has in the ABS, and that trust is in turn fundamental to the excellent quality of ABS information. Without that trust, survey respondents may be less forthcoming or truthful in answering our questionnaires. For more information, see 'Avoiding inadvertent disclosure' and 'Microdata' on our web page How the ABS keeps your information confidential.

In accordance with the Census and Statistics Act 1905, data in TableBuilder are subjected to a confidentiality process before release. The release of microdata must satisfy the ABS legislative obligation to release information in a manner that is not likely to enable the identification of a particular person or organisation.

This confidentiality process is applied to avoid releasing information that may lead to the identification of individuals, families, households, dwellings or businesses.

Prior to being granted access to TableBuilder users must agree to the following ABS Terms and Conditions of TableBuilder Access:

• understand that the ABS has taken great care to ensure that the information on the survey output record file is correct and as accurate as possible and understand that ABS does not guarantee, or accept any legal liability whatsoever arising from, or connected to, the use of any material contained within, or derived from TableBuilder
• understand that all data extracted from the Survey Output Record File through TableBuilder will be confidentialised prior to being supplied to me and that as a result, no reliance should be placed on small cells as they are impacted by random adjustment, respondent and processing errors
• inform the ABS, through your Contact Officer, upon leaving your organisation that your access is disabled
• not to provide my TableBuilder user ID and password access to any other person or organisation.

In accordance with the Census and Statistics Act 1905, data in CURFs are subjected to a confidentiality process before release. The release of microdata must satisfy the ABS legislative obligation to release information in a manner that is not likely to enable the identification of a particular person or organisation.

This legislation allows the Australian Statistician to approve release of unit record data. All CURFs released have been approved by the Statistician. Prior to being granted access to CURFs, each organisation's Responsible Officer must submit a CURF Undertaking to the ABS. The CURF Undertaking is required by legislation and states that, prior to CURFs being released to an organisation, a Responsible Officer must undertake to ensure that the organisation will abide by the conditions of use of CURFs. Individual users are bound by the undertaking signed by the Responsible Officer.

All CURF users are required to read and abide by the conditions and restrictions in the User Manual: Responsible Use of ABS CURFs. Any breach of the CURF Undertaking may result in withdrawal of service to individuals and/or organisations. Further information is contained in the Consequences of Failing to Comply web page.

All ABS products and services are provided subject to the ABS Conditions of Sale. Any queries relating to these Conditions of Sale should be referred to intermediary.management@abs.gov.au.

Microdata access is priced according to the ABS Pricing Policy and Commonwealth Cost Recovery Guidelines. For details refer to ABS Pricing Policy on the ABS website. For microdata prices refer to the Microdata prices web page.

To use this data in the TableBuilder tool, read the information on the Registration Centre web pages. To apply for access to TableBuilder products, register or log in to the Registration Centre.

To use the CURF, read the How to Apply for Microdata web page. To apply for access to the CURF, register and apply.

The ABS/Universities Australia Agreement provides participating universities with access to a range of ABS products and services. This includes access to microdata. For further information, university clients should refer to the ABS/Universities Australia Agreement web page.

The Microdata Entry page on the ABS website contains links to microdata related information to assist users to understanding and access microdata. For further information users should email microdata.access@abs.gov.au or telephone (02) 6252 7714.

This release previously used catalogue number 4715.0.30.002.