Input coding is the process by which certain data items were categorised during the interview. In the 2012-2013 National Aboriginal and Torres Strait Islander Health Survey (NATSIHS) and National Aboriginal and Torres Strait Islander Nutrition and Physical Activity Survey (NATSINPAS) these included:
- Main language spoken at home
- Industry and industry sector
- Educational qualification
- Long-term conditions
- Alcohol consumption (NATSIHS only).
Interviewers were able to code from a list of commonly used options (for example, 10 common languages spoken at home) or from a more comprehensive list contained within a 'trigram coder' (which allowed the interviewer to enter the first three letters of a response, then select the appropriate response from a pick list of options).
Standard input coding used in the 2012-2013 Australian Aboriginal and Torres Strait Islander Health Survey (AATSIHS) includes:
- Main language spoken at home — interviewers were instructed to mark the appropriate box from a list of 4 language categories: 'English', 'An Aboriginal Language', 'A Torres Strait Islander Language' and 'Other'. When the spoken language was not 'English', the interviewer then asked for the specific language spoken and selected the language from a trigram coder. If the reported language was not among those listed in the coder, interviewers recorded the name of the language for subsequent office coding. Language was coded to the Australian Standard Classification of Languages (ASCL), 2005-06 (cat. no. 1267.0).
- Occupation — occupation relates to the main job held by employed respondents at the time of their interview. Occupation was office coded, based on a description of the kind of work performed, as reported by respondents and recorded by interviewers. Occupation was coded to the 6 digit level of the Australian and New Zealand Standard Classification of Occupations (ANZSCO), First Edition, Revision 1, 2009 (cat. no. 1222.0).
- Industry and industry sector — these relate to the main job held by employed respondents at the time of their interview. These were office coded based on the name of employer and the respondent's description of the business or service carried out at the respondent's workplace. Industry was coded to the 3 digit level of the Australian and New Zealand Standard Industrial Classification (ANZSIC), 2006 (cat. no. 1292.0).
- Educational qualification — level of highest and, where applicable, current non-school educational qualification and field of study of that qualification were coded to the Australian Standard Classification of Education (ASCED), 2001 (cat. no. 1272.0).
- Relationship within a household — collected from a responsible adult in the household at commencement of the interviews. They provide basic information about all persons who live in the household. Household composition, family composition and other relationship variables are then produced either via derivations within the instrument, or via office coding.
More detail regarding use of these classifications, except relationship in household, is contained in Appendix 3: ABS Standard Classifications
Survey specific input coding includes:
- Long-term conditions — all reported long-term medical conditions were coded to a 3 digit code from a list of pre-determined conditions. The code list was compiled for use in the 2001 National Health Survey (NHS) by the Family Medicine Research Centre, University of Sydney, in association with the ABS. Conditions classified at the full level of detail will not generally be available for output from the survey, although they can be regrouped in various ways for output. Both the standard output classification developed for the health surveys, used in the 2012-13 NATSIHS, and mini version of the ICD-10 classification, used in the 2012-13 NATSINPAS (and available as part of the Core (combined NATSIHS and NATSINPAS sample)), is available in Appendix 2: Classification of health conditions.
- Alcohol consumption (NATSIHS only) — information about alcohol consumption was recorded against 14 general categories of alcoholic drinks: beer (light, medium, full), wine (white, red, low alcohol), champagne/sparkling wine, ready-to-drink spirits, liqueurs, spirits, fortified wine, cider, cocktails and other alcoholic beverages. Interviewers were asked to use a trigram coder to record further details about the brand or name of drink where possible to assist in coding. Details of the quantity of each of these drinks consumed on three drinking days in the previous week to interview, and heaviest drinking day in the last two weeks were recorded. A conversion factor was applied to this information to obtain the amount of pure alcohol consumed. This process was complemented by an automated coding system, supported by clerical coding when the auto-code could not find a match.