Data quality statement: National Elective Surgery Waiting Times Data Collection 2011–12

This data quality statement provides information relevant to interpretation of the National Elective Surgery Waiting Times Data Collection (NESWTDC) for 2011–12.

•         The NESWTDC provides episode-level data on patients added to or removed from elective surgery waiting lists managed by public hospitals.

•         For 2011–12, the NESWTDC covered most hospitals that undertook elective surgery. Hospitals that were not included may not undertake elective surgery, may not have had waiting lists, or may have had different waiting lists compared with other hospitals.

•         For 2011–12, the proportion of public hospital elective surgery reported to the NESWTDC was estimated to be 97%.

•         Although there are national standards for data on elective surgery waiting times, methods to calculate waiting times have varied between states and territories and over time. For example, some states and territories vary in how they report on patients transferred from a waiting list managed by one hospital to that managed by another.

•         The quality of the data reported for Indigenous status for the NESWTDC has not been formally assessed; therefore, caution should be exercised when interpreting these data.

•         There is an apparent lack of comparability of clinical urgency categories among jurisdictions that may result in statistics that are not meaningful or comparable between jurisdictions. For example, the proportion of patients admitted from elective surgery waiting lists who were assigned a clinical urgency category of Category 1 varied from 23% to 43% across states and territories. The proportion of patients admitted that were Category 3 varied from 14% to 43%.

•         There is apparent variation in recording practices for waiting times for elective surgery for patients awaiting ‘staged’ procedures (such as follow-up care, cystoscopy or the removal of pins or plates) that may result in statistics that are not meaningful or comparable between or within jurisdictions.

The NESWTDC provides episode-level data on patients added to or removed from elective surgery waiting lists managed by public hospitals. This includes private patients treated in public hospitals, and may include public patients treated in private hospitals. ‘Public hospitals’ may include hospitals that are set up to provide services for public patients (as public hospitals do), but are managed privately. 

The data supplied for 1 July 2011 to 31 December 2011 are based on the Elective surgery waiting times (removals data) National Minimum Data Set (ESWT NMDS). The data contains records for patients added to and/or removed from waiting lists for elective surgery that are managed by public acute hospitals. The data supplied for 1 January 2012 to 30 June 2012 are based on the Elective Surgery Waiting Times (removals data) Data Set Specification (ESWT DSS).

Removals are counted for patients who have been removed for admission or for another reason.

The NESWTDC includes data for each year from 2002–03 to 2011–12.

The Australian Institute of Health and Welfare (AIHW) is a major national agency set up by the Australian Government under the Australian Institute of Health and Welfare Act 1987 to provide reliable, regular and relevant information and statistics on Australia’s health and welfare. It is an independent statutory authority established in 1987, governed by a management board, and accountable to the Australian Parliament through the Health and Ageing portfolio.

The AIHW aims to improve the health and wellbeing of Australians through better health and welfare information and statistics. It collects and reports information on a wide range of topics and issues, ranging from health and welfare expenditure, hospitals, disease and injury, and mental health, to ageing, homelessness, disability and child protection.

The Institute also plays a role in developing and maintaining national metadata standards. This work contributes to improving the quality and consistency of national health and welfare statistics. The Institute works closely with governments and non-government organisations to achieve greater adherence to these standards in administrative data collections to promote national consistency and comparability of data and reporting.

One of the main functions of the AIHW is to work with the states and territories to improve the quality of administrative data and, where possible, to compile national datasets based on data from each jurisdiction, to analyse these datasets and disseminate information and statistics.

The Australian Institute of Health and Welfare Act 1987, in conjunction with compliance to the Privacy Act 1988 (Cwlth), ensures that the data collections managed by the AIHW are kept securely and under the strictest conditions with respect to privacy and confidentiality.

For further information see the AIHW website <www.aihw.gov.au>

Data for the NESWTDC were supplied to the AIHW by state and territory health authorities under the terms of the National Health Information Agreement (see the following links):

<http://www.aihw.gov.au/nhissc/>

< /content/index.phtml/itemId/182135>

The state and territory health authorities received these data from public hospitals. States and territories use these data for service planning, monitoring and internal and public reporting. Hospitals may be required to provide data to states and territories through a variety of administrative arrangements, contractual requirements or legislation.

Data for the NESWTDC are reported annually. The reference period for this data set is 2011–12. This includes records for additions and removals from elective surgery waiting lists between 1 July 2011 and 30 June 2012.

States and territories provided a first version of the data to the AIHW during August 2012. These data were reported in October 2012. Data provision and publication were in accordance with agreed timetables.

The AIHW provides a variety of products that draw upon the NESWTDC. Published products available on the AIHW website are the:

•     Australian hospital statistics suite of products with associated Excel tables.

These products may be accessed on the AIHW website <http://www.aihw.gov.au/hospitals/>

Metadata information for the ESWT NMDS and ESWT DSS are published in the AIHW’s online metadata repository—METeOR, and the National health data dictionary.

METeOR and the National health data dictionary can be accessed on the AIHW website:

</content/index.phtml/itemId/181162>

<http://www.aihw.gov.au/publication-detail/?id=6442468385>

The NESWTDC provides information on waiting times for elective surgery in public hospitals. The scope of the data collection is patients on waiting lists for elective surgery that are managed by public hospitals. This includes private patients treated in public hospitals, and may include public patients treated in private hospitals.

For 2011–12, the NESWTDC covered most public hospitals that undertook elective surgery. Hospitals that were not included may not undertake elective surgery, may not have had waiting lists, or may have had different waiting lists compared with other hospitals. For 2011–12, the proportion of public hospital elective surgery covered by the NESWTDC was estimated to be 97%. Coverage of the NESWTDC has increased over time from 85% of public hospital elective surgery in 2002–03 (see ‘Coherence’).

The reference period for this data set is 2011–12. This includes records for additions and removals from elective surgery waiting lists between 1 July 2011 and 30 June 2012.

States and territories are primarily responsible for the quality of the data they provide. However, the AIHW undertakes extensive validations on receipt of data. Data are checked for valid values, logical consistency and historical consistency. Where possible, data in individual data sets are checked with data from other data sets. Potential errors are queried with jurisdictions, and corrections and resubmissions may be made in response to these edit queries. The AIHW does not adjust data to account for possible data errors or missing or incorrect values, except as stated.

Although there are national standards for data on elective surgery waiting times, statistics may be affected by variations in methods used to calculate waiting times across states and territories and over time.

In some states and territories, for patients who were transferred from a waiting list managed by one hospital to that managed by another, the time waited on the first list is not included in the waiting time reported to the NESWTDC from the second hospital. Therefore, the number of days waited in those jurisdictions reflected the waiting time on the list managed by the reporting hospital only.

There is an apparent lack of comparability of clinical urgency categories among jurisdictions that may result in statistics that are not meaningful or comparable between jurisdictions. For example, the proportion of patients admitted from elective surgery waiting lists who were assigned a clinical urgency category of Category 1 varied from 23% to 43% across states and territories. The proportion of patients admitted that were Category 3 varied from 14% to 43%.

There is apparent variation in recording practices for waiting times for elective surgery for patients awaiting ‘staged’ procedures (such as follow-up care, cystoscopy or the removal of pins or plates), that may result in some statistics that are not comparable between or within jurisdictions.

The quality of the data reported for Indigenous status for the NESWTDC has not been formally assessed; therefore, caution should be exercised when interpreting these data.

The AIHW does not adjust data to account for possible data errors or missing or incorrect values.

The data reported for the 2011–12 NEWSTDC are consistent with data reported for previous years for individual hospitals.

Time series presentations may be affected by changes in the number of hospitals reported to the collection and changes in coverage (see ‘Relevance’).

Time series analyses may also be affected by changes in quality and coverage for individual data items. For example, data for Indigenous status was first included in the collection in 2009–10. New South Wales first provided Indigenous status for the NEWSTDC in 2010–11.

The following changes in overall coverage should be taken into account when interpreting changes over time:

•         Between 2002–03 and 2011–12, the number of hospitals reporting to the NESWTDC increased from 191 to 244. Over the same period, the estimated proportion of public elective surgery that was reported to the NEWSTDC increased from 90% to 97%.

•         For 2011–12, South Australia provided data for 32 small hospitals that were not included in the data for previous years. Coverage increased from 71% in 2010–11 to 96% (estimated) in 2011–12.

•         For 2011–12, Western Australia provided data for 22 small hospitals that were not included in the data for previous years. Coverage increased from 94% in 2010–11 to 100% (estimated) in 2011–12.

•         For 2011–12, Queensland was not able to provide data for 3 hospitals that reported almost 10,000 admissions from elective surgery waiting lists in 2010-11.

•         For 2011–12 and 2010–11, Victoria’s data does not include the Albury Base Hospital as the data were not available. For 2009–10, Albury Base Hospital was included in data for Victoria. In previous years, that hospital was included in data for New South Wales.