Use of ABS microdata and impact on research quality
ABS microdata products in the context of confidentiality controls, and impact of data treatments on analysis
ABS microdata products
ABS releases microdata products that can be accessed for statistical and research purposes:
- basic microdata which can be downloaded into a user's own computing environment
- detailed microdata files, available through the ABS DataLab
ABS also releases TableBuilder, which uses underlying microdata to allow researchers to create their own automatically confidentialised tables, graphs and maps (aggregate output).
Each product is designed to meet a different research requirement. A comparison of these products is shown in Table 1. You can also Compare data services for more detail about a wider range of ABS products.
| Microdata product | Basic microdata | Detailed microdata | TableBuilder |
|---|---|---|---|
| Access via |
| ||
| Utility and suitability | Basic utility:
| Very high utility:
| High utility:
|
| Purpose |
|
|
|
| Confidentiality controls applied | |||
| Data treatment |
|
|
|
| Context controls |
|
|
|
Impact of data treatment on analysis
Treating the data itself may restrict the ability of a researcher to answer a particular question. For example, a major difference between basic microdata and detailed microdata is that data item categories in the former have been collapsed or aggregated to a greater degree, which reduces the level of detail available. In some instances it may therefore be more appropriate to use an Expanded CURF. Similarly, it may be better to conduct research (within the ABS DataLab) using detailed microdata files if the Expanded CURF does not contain enough detail to answer the researcher's question.
There are, however, situations where data treatment may not adversely affect the quality of the data or the reliability of the research. For example, a 2010 study used data from the ABS's Survey of Mental Health (2007) to compare results attained from using the Expanded CURF with results attained from using the untreated main-unit-record file (MURF). As Table 2 shows, the results were almost identical.
| Disorder | Hazard ratio (from treated microdata) | Hazard ratio (from original microdata) | Standard error of hazard ratio | Difference between hazard ratios, as proportion of standard error |
|---|---|---|---|---|
| No lifetime mental disorder | 1 | 1 | (reference category) | |
| Anxiety disorder (type): | ||||
| Panic disorder | 0.59678 | 0.59615 | 0.10335 | 0.0102 |
| Agoraphobia | 0.44936 | 0.44936 | 0.0842 | 0 |
| Social phobia | 0.55374 | 0.55374 | 0.07973 | 0 |
| Generalised anxiety disorder | 0.33631 | 0.33631 | 0.07846 | 0 |
| Obsessive-compulsive disorder | 0.47782 | 0.47782 | 0.10674 | 0 |
| Post-traumatic stress disorder | 0.63221 | 0.63221 | 0.07865 | 0 |
| Anxiety disorder (severity): | ||||
| Mild | 0.74901 | 0.74882 | 0.11495 | 0.00218 |
| Moderate | 0.58942 | 0.5892 | 0.08275 | 0.00447 |
| Severe | 0.39196 | 0.39202 | 0.06016 | 0.00249 |
* Hazard ratios compare the incidence of an event in one group to another group over time
Source: Lawrence, D., Considine, J., Mitrou, F. & Zubrick, S.R. (2010) ‘Anxiety disorders and cigarette smoking: Results from the Australian Survey of Mental Health and Wellbeing’, Australian and New Zealand Journal of Psychiatry. Vol. 44, pp. 521-528.