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National Healthcare Agreement: PI 18-Selected potentially preventable hospitalisations, 2014 QS

Identifying and definitional attributes

Metadata item type:Help on this termQuality Statement
METeOR identifier:Help on this term517739
Registration status:Help on this termHealth, Superseded 14/01/2015

Relational attributes

Indicators linked to this Quality statement:Help on this term

National Healthcare Agreement: PI 18-Selected potentially preventable hospitalisations, 2014 Health, Superseded 14/01/2015

Data quality

Quality statement summary:Help on this term

The National Hospital Morbidity Database (NHMD) is a comprehensive data set that has records for all separations of admitted patients from essentially all public and private hospitals in Australia.

Separations are reported by the jurisdiction of usual residence of the patient, not the jurisdiction of hospitalisation.

Caution should be used in comparing 2007–08 data with later years as changes between the International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, Australian Modification (ICD-10-AM) 5th edition (used in 2007–08), ICD-10-AM 6th edition (used in 2008–09 and 2009–10) and ICD-10-AM 7th edition (used in 2010–11 and 2011–12) and the associated Australian Coding Standards resulted in decreased reporting of additional diagnoses for diabetes, and increased reporting of gastroenteritis (chronic and acute categories, respectively, affected). These changes should also be taken into consideration in interpretation of these data against the National Healthcare Agreement performance benchmark for potentially preventable hospitalisations.

In addition, interpretation of the related performance benchmark over time is problematic because the benchmark is specified as a proportion of separations rather than a population rate, and admission practices vary across jurisdictions and over time.  

The hospital separations data do not include episodes of non-admitted patient care provided in outpatient clinics or emergency departments.

Variations in admission practices and policies lead to variation among providers in the number of admissions for some conditions.

Socio-Economic Indexes for Areas (SEIFA) data for 2011–12 are not directly comparable with SEIFA data from previous reporting cycles.

Institutional environment:Help on this term

The Australian Institute of Health and Welfare (AIHW) has calculated this indicator.

The 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 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 NHMD 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/

http://meteor.aihw.gov.au/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.

Timeliness:Help on this term

The reference period for this data set is 2011–12.

Accessibility:Help on this term

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

  • Australian hospital statistics with associated Excel tables
  • interactive data cubes for Admitted patient care (for Principal diagnoses, Procedures and Diagnosis Related Groups).

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

Interpretability:Help on this term

Supporting information on the quality and use of the NHMD are published annually in Australian hospital statistics (technical appendixes), available in hard copy or on the AIHW website. Readers are advised to note caveat information to ensure appropriate interpretation of the performance indicator. Supporting information includes discussion of coverage, completeness of coding, the quality of Indigenous data, and variation in service delivery that might affect interpretation of the published data. Metadata information for the NMDS for Admitted patient care is published in the AIHW’s online metadata repository, METeOR, and the National health data dictionary.

The National health data dictionary can be accessed online at:

http://www.aihw.gov.au/publication-detail/?id=10737422826

The Data Quality Statement for the National Hospital Morbidity Database can be accessed on the AIHW website at:

http://meteor.aihw.gov.au/content/index.phtml/itemId/529483

Relevance:Help on this term

The purpose of the NMDS for Admitted patient care is to collect information about care provided to admitted patients in Australian hospitals. The scope of the NMDS is episodes of care for admitted patients in essentially all hospitals in Australia, including public and private acute and psychiatric hospitals, free-standing day hospital facilities, alcohol and drug treatment hospitals and dental hospitals. Hospitals operated by the Australian Defence Force, corrections authorities and in Australia's off-shore territories are not included. Hospitals specialising in ophthalmic aids and other specialised acute medical or surgical care are included.

The hospital separations data do not include episodes of non-admitted patient care provided in outpatient clinics or emergency departments.

The analyses by state and territory, remoteness and socioeconomic status are based on the Statistical Local Area (SLA) of usual residence of the patient, not the location of the hospital. Hence rates represent the number separations for patients living in each state/territory, remoteness area or Socio-Economic Indexes for Areas (SEIFA) population group (regardless of the jurisdiction of the hospital they were admitted to) divided by the total number of people living in that remoteness area or SEIFA group in the state/territory.

The SEIFA categories for socioeconomic status represent approximately the same proportion of the national population, but do not necessarily represent that proportion of the population in each state or territory (each SEIFA decile or quintile represents 10 per cent and 20 per cent respectively of the national population). The SEIFA scores for each SLA are derived from 2011 Census data and represent the attributes of the population in that SLA in 2011.

Other Australians includes separations for non-Indigenous people and those for whom Indigenous status was not stated.

Accuracy:Help on this term

For 2011–12 almost all public hospitals provided data for the NHMD, with the exception of all separations for a mothercraft hospital in the Australian Capital Territory.

The majority of private hospitals provided data, with the exception of the private day hospital facilities in the Australian Capital Territory and the Northern Territory.

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 against 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.

The AIHW report Indigenous identification in hospital separations data: quality report (AIHW 2013) found that nationally, about 88 per cent of Indigenous Australians were identified correctly in hospital admissions data in the 2011–12 study period, and the ‘true’ number of separations for Indigenous Australians was about 9 per cent higher than reported. The report recommended that the data for all jurisdictions are used in analysis of Indigenous hospitalisation rates, for hospitalisations in total in national analyses of Indigenous admitted patient care. However, these data should be interpreted with caution as there is variation among jurisdictions in the quality of the Indigenous status data.

Variations in admission practices and policies lead to variation among providers in the number of admissions for some conditions.

Cells have been suppressed to protect confidentiality where the presentation could identify a patient or a service provider or where rates are likely to be highly volatile, for example where the denominator is very small. The following rule was applied:

  • Rates were suppressed where the numerator was less than 5 and/or the denominator was less than 1,000.
Coherence:Help on this term

The information presented for this indicator is calculated using the same methodology as data published in Australian hospital statistics 2011–12 and the National healthcare agreement: performance report 2011–12.

However, caution should be used when comparing 2007–08 with later years due to changes between the ICD-10-AM 5th edition (used in 2007–08), the ICD-10-AM 6th edition (used in 2008–09 and 2009–10) and ICD-10-AM 7th edition (used in 2010–11 and 2011–12) and the associated Australian Coding Standards that resulted in:

  • decreased reporting of additional diagnoses for diabetes
  • increased reporting of diagnoses for dehydration and gastroenteritis.

In light of these comparability issues, the data presented for 2011–12 exclude:

  • Diabetes complications (additional diagnoses only) from the chronic conditions category, and
  • Dehydration and gastroenteritis from the acute conditions category, and  
  • Diabetes complications (additional diagnoses only) and dehydration and gastroenteritis from the total.

However it should be acknowledged that these data are not consistent with the original intent of the indicator.

In addition, Tasmanian data are not comparable over time as 2008–09 data for Tasmania does not include two private hospitals that were included in 2007–08 and 2009–10 data reported in the National Healthcare Agreement performance reports.

Interpretation of the related performance benchmark over time is also problematic because the benchmark is specified as a proportion of separations rather than a population rate, and admission practices vary across jurisdictions and over time. Changes in a jurisdiction’s denominator (separations) can artificially increase or decrease the results of the benchmark. Therefore the data provided in 2014–15 (and interim years) may not be directly comparable to the baseline data from which the target is based.

Methodological variations also exist in the application of SEIFA to various data sets and performance indicators. Any comparisons of the SEIFA analysis for this indicator with other related SEIFA analysis should be undertaken with careful consideration of the methods used, in particular the SEIFA Census year, the SEIFA index used and the approach taken to derive quintiles and deciles.

National level data disaggregated by Indigenous status for 2007–08 included data from NSW, Qld, WA, SA and NT. National level data disaggregated by Indigenous status for 2008–09, 2009–10 and 2010–11 included data from NSW, Victoria, Qld, WA, SA and NT. National level data disaggregated by Indigenous status for 2011–12 and subsequent years includes data from all eight states and territories. Therefore, data disaggregated by Indigenous status from 2007–08 is not comparable to 2008–09, 2009–10 and 2010–11,  and data for 2011–12 and subsequent years are not comparable with data for 2010–11 and prior years.   

Following the 2011 Census of Population and Housing, the Australian Bureau of Statistics (ABS) has rebased the Australian population back to 1991.  This rebasing had a significant impact on the population time series, therefore data have been resupplied for previous years using the rebased Estimated Resident Population (ERP).  The exception is for data presented by Indigenous status.  Rebased Indigenous population data are not yet available, thus data presented by Indigenous status use 2006 based ERP.

In 2011, the ABS updated the Socio-Economic Indexes for Areas (SEIFA), based on the 2011 ABS Census of Population and Housing.  The new SEIFA will be referred to as SEIFA 2011, and the previous SEIFA as SEIFA 2006.  Data for 2007-08 through to 2010-11 reported for SEIFA quintiles and deciles are reported using SEIFA 2006 at the Statistical Local Area (SLA) level.  Data for 2011-12 are reported using SEIFA 2011 at the SLA level.  The AIHW consider the change from SEIFA 2006 to SEIFA 2011 to be a series break when applied to data supplied for this indicator, therefore SEIFA data for 2011-12 are not directly comparable with SEIFA data from previous reporting cycles.

Relational attributes

Related metadata references:Help on this term

Supersedes National Healthcare Agreement: PI 18-Selected potentially preventable hospitalisations, 2013 QS Health, Superseded 14/01/2015

Has been superseded by National Healthcare Agreement: PI 18-Selected potentially preventable hospitalisations, 2015 QS Health, Superseded 08/07/2016

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