This document was added or updated on 13/12/2013.

DATA COLLECTION

Information in the 2011-12 NHS and NNPAS was obtained by trained ABS interviewers, through Computer Assisted Personal Interview (CAPI) and, for the second NNPAS interview through Computer Assisted Telephone Interview (CATI), with all selected members of in-scope households (see Scope and Sample Design and Selection for further information). For the purposes of this survey, a household was defined as one or more persons, at least one of whom is aged 18 years and over, usually resident in the same private dwelling.

Interviewers

Interviewers were recruited from a pool of trained interviewers with previous experience on ABS household surveys where possible, and undertook further classroom training and a requirement to satisfactorily complete home study exercises. Training emphasised understanding of survey concepts, definitions and procedures to ensure that a standard approach was employed by all interviewers. Regular communication between field staff and survey managers was maintained throughout the survey via database systems set up for the survey.

Interviewers were allocated a number of dwellings (a workload) at which to conduct interviews. The size of the workload was dependent upon the area involved and whether or not the interviewer was required to live away from home to collect the data. Interviewers living close to their workload area in urban areas usually had larger workloads. Overall, workloads were to be enumerated over a two-week period and averaged in size:

• 25-30 dwellings for NHS
• 10-15 dwellings for NNPAS.

Dwellings selected in NNPAS with at least one respondent who completed their interview and provided a contact phone number were allocated to NNPAS CATI workloads. Dwellings were progressively released to interviewers once the '8 days since CAPI interview' timeframe had passed for all respondents in a dwelling.

Interviews
All selected households were initially approached by mail (the 'primary approach letter'), informing them of their selection in the survey and advising that an interviewer would visit to arrange a suitable time to conduct the survey interview. This was not possible for a small number of households for which ABS did not have an adequate postal address. A brochure providing background to the survey, information concerning the interview process and information regarding confidentiality provisions under the Census and Statistics Act 1905 were included with the primary approach letter.

General characteristics of the household were obtained from any responsible adult (ARA) member of the household. This information included the number and basic demographic characteristics of usual residents of the dwelling, and the relationships between those people (e.g. spouse, son/daughter, not related). The ARA was also asked to nominate the person in the household who was best able to provide information about children in the household.

From the information about the composition of the household, those persons in scope of the survey were determined, and, on a random basis, one adult and one child (where applicable) were selected for inclusion in the survey.

If the dwelling contained only usual residents aged under 18 years, no further information was collected from that household.

If the dwelling contained more than fifteen usual residents, all of whom were in scope, then whether there was more than one family group living in the dwelling was determined. Each family group was then treated as a separate household.

A personal interview was conducted with the selected adult (where possible), and an adult was asked to respond on behalf of the selected child aged under 15 years (see below for further details regarding children involved in answering some questions in the NNPAS interview). In some instances, adult respondents were unable to answer for themselves due to significant long-term illness or disability. In these cases, a person responsible for them was interviewed on their behalf, provided the interviewer was assured that this was acceptable to the selected person. Where possible, the respondent was still present during the interview and physical measurements were taken where appropriate. If the respondent was not able to be present for the interview certain questions were not asked and the biomedical component (NHMS) was not offered.

In limited circumstances where there were language difficulties, other persons in the household may have acted as an interpreter if this was suggested by the respondent. If not, arrangements were made where possible for the interview to be conducted either by an ABS interviewer fluent in the respondent’s own language, or with an ABS interpreter.

Where permission was granted by a parent or guardian, children aged 15-17 years were interviewed in person. If permission was not granted, questions were answered by an adult, who may or may not have been the selected adult respondent in the household. The person answering on behalf of the 15-17 year old is referred to as the Child Proxy. Whether a child proxy was used for an interview is available as a data item. There are also data items available identifying parent presence or proxy use at other stages of the survey, including Healthy lifestyles (NHS only), Alcohol (NHS only) and Smoking.

To obtain a personal interview with appropriate respondents, interviewers made appointments as necessary with the household. In some cases appointments were made by telephone, however all interviews were conducted face-to-face, with the exception of the second interviews for NNPAS which were conducted by telephone using CATI. Interviews may have been conducted in private or in the presence of other household members according to the wishes of the respondent.

Interviews were conducted on Sundays only when specifically requested by a respondent. Although it is desirable to spread interviews across all days of the week, interviews were conducted on days that suited respondents.

For the NNPAS, child involvement in the survey was encouraged, in particular for the physical activity modules and the 24-hour dietary recall. The following principles were applied where practical:

Population age	Food Recall and Physical Activity Questions
2-5	Proxy only.
6-8 9-11	Proxy, child can assist. Interview child directly. Proxy there to assist.
12-14	Interview child directly. Proxy must remain in the same room.
15-17	Interview child directly.

At the end of the physical activity module and 24-hour dietary recall, interviewers were asked to identify the involvement of the child (aged 6 years and over) with these modules and are available as data items.

Questionnaire

The 2011-12 NHS and NNPAS utilised Computer Assisted Interview (CAI) instruments to collect the data.

The CAI instrument allows:

• data to be captured electronically at the point of interview, which obviates the cost, logistical, timing and quality issues associated with transport, storage and security of paper forms, and transcription/data entry of information from forms into electronic format
• the ability to use complex sequencing to define specific populations for questions, and ensure word substitutes used in the questions were appropriate to each respondent's characteristics and prior responses
• the ability, through data validation (edits), to check responses entered against previous responses, reduce data entry errors by interviewers, and enable seemingly inconsistent responses to be clarified with respondents at the time of interview. The audit trail recorded in the instrument also provides valuable information about the operation of particular questions, and associated data quality issues
• some derivations to occur in the instrument itself, assisting in later processing
• auto-coding systems to be incorporated, reducing interview and processing time
• data to be delivered in an electronic format compatible with ABS data processing facilities.

The questionnaires were field tested to ensure:

• data was obtained in an efficient and effective way
• there was minimum respondent concern about the sensitivity or privacy aspects of the information sought
• there was effective respondent/interviewer interaction and acceptable levels of respondent burden
• operational aspects of the survey were satisfactory; e.g. arrangement of topics, sequencing of questions, adequacy and relevance of coding frames, etc.

The questionnaires employed a number of different approaches for recording information at the interview.

• Questions where responses were classified by interviewers to one or more of a set of predetermined response categories. This approach was used for recording answers to the more straightforward questions, where logically a limited range of responses was expected or where the focus of interest was on a particular type or group of responses (which were listed in the questionnaire, with the remainder being grouped together under ‘other’).
• Questions where responses were recorded by interviewers as reported, for subsequent classification and coding by office staff during processing. This style of question was used for potentially more complex topics such health conditions or medications used.
• Questions asked in the form of a running prompt; that is, predetermined response categories were read out to the respondent one at a time until the respondent indicated agreement to one or more of the categories (as appropriate to the topic) or until all the predetermined categories were exhausted.
• Questions asked in association with prompt cards. Printed lists of possible answers to the question were shown the respondent who was asked to select relevant responses. Listing a set of possible responses (either in the form of a prompt card or a running prompt question) served to clarify the question or to present various alternatives, to refresh the respondent’s memory and at the same time assist the respondent to select an appropriate response.
• Procedures for obtaining the measured height, weight, waist circumference and blood pressure of respondents. Interviewers took the physical measurements using a variety of techniques (see: Body Mass and Physical Measurements and Blood Pressure for more information).

To ensure consistency of approach, interviewers were instructed to ask the interview questions exactly as written. In certain areas of the questionnaire however, interviewers were asked to use indirect and neutral prompts at their discretion, where the response given was, for example, inappropriate to the question asked or lacked sufficient detail necessary for classification and coding. This occurred particularly in relation to type of medical condition where interviewers were asked to prompt for a condition if a treatment or symptom was initially reported.

The questionnaires were designed to be administered using standard ABS procedures for conducting population interview surveys, with regard to the particular aims of the survey and the individual topics within it, and the methodological issues associated with those topics. Other factors considered in designing the questionnaires included the length of individual questions, the use of easily understood words and concepts, the number of subjects and overall length of the questionnaires, and the sensitivity of topics. Where appropriate, previous ABS questions on the topics covered were adopted.

National Health Survey

The questionnaire used for the 2011-12 NHS was based on the 2007-08 NHS, modified as appropriate to incorporate new and changed survey content. Information collected included:

• Household information - basic demographic data about usual residents of the household (e.g. sex, age, date of birth, birthplace, Indigenous status, marital status) and details of the relationship between individuals in each household. This information was obtained from the ARA. The data was also used to enable the selection of respondents in the dwelling. Information was also recorded on the calls made to the dwelling by the interviewer, and the subsequent response status of the household in the survey (e.g. fully responding, refusal, vacant dwelling, etc.).
• Personal Adult Interview - information was collected from the selected adult about demographic, socio-economic and health characteristics (e.g. physical measurements, long-term health conditions, risk factors, and health-related actions they had taken).
• Personal (or proxy) Child Interview - information was collected on selected demographic and health characteristics. Questions on socio-economic characteristics, smoking and alcohol were not asked of children aged under 15 years, and questions on levels of psychological distress were not asked of persons aged under 18 years. Physical measurements were taken for children aged 2 years and older (5 years and older for blood pressure measurements).

National Nutrition and Physical Activity Survey

The questionnaire used for the 2011-12 NNPAS comprised multiple approaches to collection. The NNPAS questionnaire was generally based on the 2011-12 NHS. Information collected from the primary questionnaire included:

• Household information - basic demographic data about usual residents of the household (e.g. sex, age, date of birth, birthplace, Indigenous status, marital status) and details of the relationship between individuals in each household. This information was obtained from the ARA. The data was also used to enable the selection of respondents in the dwelling. Information was also recorded on the calls made to the dwelling by the interviewer, and the subsequent response status of the household in the survey (e.g. fully responding, refusal, vacant dwelling, etc.).
• Personal Adult Interview - information was collected from the selected adult about demographic, socio-economic and health characteristics (e.g. physical measurements, selected long-term health conditions, and risk factors).
• Personal (or proxy) Child Interview - information was collected on selected demographic and health characteristics, including specific physical activity modules for 2-4 years and 5-17 years. Questions on socio-economic characteristics and smoking were not asked of children aged under 15 years. Physical measurements were taken for children aged 2 years and older (5 years and older for blood pressure measurements).

In addition to the primary questionnaire, additional collection methods and instruments were developed to support special requirements for components of the survey.

• Due to the size and complexity of the 24-hour dietary recall collection, a separate instrument was developed for use in the CAPI and the CATI. Specific information on the content and collection methodology of the 24-hour dietary recall component is provided in more detail in the Nutrition chapter of this Users' Guide.
• The collection of Pedometer data involved distributing a Daily Activity Sheet to respondents who agreed to participate in this component during the CAPI. This sheet (an example of which can be found in the Downloads page of this product) was then used by the respondent to record specified information for each day (up to 8 days) that they wore the pedometer. The follow-up telephone interview (CATI) used to collect 2^nd day dietary recall data was also used to collect from participating respondents their Pedometer data. Specific information on the content and collection methodology of the Pedometer component is provided in more detail in the Pedometer Steps chapter of this Users’ Guide.

National Health Measures Survey

The 2011-12 National Health Measures Survey (NHMS) involved respondents volunteering to provide blood and/or urine samples for analysis.

The interview components of the NHS and NNPAS were conducted under the Census and Statistics Act (CSA) 1905. Ethics approval was sought and gained (for the NHMS component only) from the Australian Government Department of Health and Ageing’s Departmental Ethics Committee.

At the completion of NHS or NNPAS questions, interviewers explained the voluntary Biomedical component and provided a written Information Sheet. Only selected respondents aged 5 years and above were in scope and for children aged 5–11 only urine samples were requested. Respondents were determined to be out of scope of the NHMS in proxy interviews where the situation was deemed appropriate to use a proxy for the adult interview and the respondent was not present.

Informed consent was sought from adults and from parents/legal guardians of children through completion of a consent form. A copy of the consent form was left with the respondent. Those that agreed to take part were provided a Referral Form to complete (including whether specific medications or supplements were regularly taken) to provide to the collection centre. Examples of these referral and consent forms can be found in the Downloads page of this product.

Pathology tests conducted in the NHMS included markers of chronic disease such as blood sugar levels, cholesterol and kidney function, markers of nutritional status, as well as markers of exposure to chemicals such as nicotine.

Specific information on the content, collection methodology, quality assurance of the biomedical component can be found in the Biomedical Measures chapter of this Users' Guide.

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