Australian Government: Australian Institute of Health and Welfare METeOR Home Page

National Healthcare Agreement: P44-Survival of people diagnosed with cancer, 2010 QS

Identifying and definitional attributes

Metadata item type:Help on this termQuality Statement
METeOR identifier:Help on this term393045
Registration status:Help on this termHealth, Superseded 08/06/2011

Relational attributes

Indicators linked to this Quality statement:Help on this term

National Healthcare Agreement: P44-Survival of people diagnosed with cancer, 2010 Health, Superseded 08/06/2011

Data quality

Quality statement summary:Help on this term
  • Data are only available from the Australian Institute of Health and Welfare (AIHW) at the national level this year. To date this indicator has been produced by the AIHW irregularly, according to funded ad-hoc requests. Data available for the 2010 CRC baseline report were published in Cancer survival and prevalence in Australia: cancers diagnosed from 1982 to 2004.
  • The indicator cannot be reported by Indigenous status this year as Indigenous identification in the data is not adequate to support analysis or generation of life tables.
  • The indicator as currently specified is not age adjusted which limits comparability across groups and over time.
  • Cancer staging and treatment data are not currently available nationally and cancer survival analysis would benefit greatly from this additional information.
  • Cancer survival varies by cancer type. As this indicator is based on all cancers (except two types of skin cancer), differences in the relative incidence of different types of cancer between groups may affect comparability.
Institutional environment:Help on this term

The AIHW has calculated this indicator with assistance from the Australasian Association of Cancer Registries (AACR).

Cancer incidence data used for the numerator are supplied by cancer registries with additional death information updated from linkage to the National Death Index (NDI). Expected survival data in the denominator are calculated using life tables from the Australian Bureau of Statistics (ABS) and data from the National Mortality Database (NMD). Both data sources are robust and the matching of numerator to denominator is appropriate.

Numerator

Cancer incidence data are supplied to the AIHW by state and territory cancer registries under a protocol last revised August 2009. These data are compiled to form the Australian Cancer Database (ACD). All jurisdictions have legislation requiring mandatory reporting of all cancer cases with the exception of basal cell carcinoma and squamous cell carcinoma. This means cancer incidence ascertainment is complete for all other cancers.

Cancer incidence data sent to the AIHW already contain some mortality information. In addition to this, cancer records on the ACD are linked to the NDI to obtain date of death. The NDI is a national compilation of data on all deaths occurring in each jurisdiction. Data are supplied by Registrars of Births Deaths and Marriages (RBDM) from each state and territory and this results in a database which contains all deaths occurring in Australia since 1980. RBDM have legislation to collect information on all deaths occurring in their jurisdiction. NDI data are provided by state and territory RBDM to AIHW on a monthly basis under an MOU last revised in September 2009. This is a robust data source and appropriate to apply to cancer data.

Denominator

Life tables are needed to calculate expected survival in the general population. Australia-wide life tables are published by the ABS but tables by remoteness or socioeconomic status are not readily available. Therefore it is necessary to derive approximate life tables for these subpopulations. In order to build a life table for subpopulation ‘S’, the following two pieces of information are required for each combination of calendar year, sex and 1-year age group:

  • the mid-year population of S for that calendar year, sex and age
  • the number of deaths in S for that calendar year, sex and age.

The methods used by AIHW to construct those data and the subsequent life tables are explained on pp 73–76 of the publication Cancer survival and prevalence in Australia: cancers diagnosed from 1982 to 2004.

The AIHW is Australia's national agency for health and welfare statistics and information. The role of the AIHW is to provide information on Australia's health and welfare, through statistics and data development that inform discussion and decisions on policy and services.

The AIHW works closely with all state, territory and Australian government health authorities in collecting, analysing and disseminating data. However, the AIHW is an independent statutory authority within the Health and Ageing portfolio, and is responsible to the Minister for Health and Ageing. The Institute is governed by a Board, which is accountable to the parliament of Australia through the Minister.

When errors are found in published data, those errors are corrected immediately with the revised version posted on the AIHW website and where necessary in on-line tables and online interactive data cubes. Corrections are documented on the AIHW website.

Timeliness:Help on this term

Data available for the 2010 CRC baseline report is previously published data. The indicator is based on cancers diagnosed from 1982 to 2004. However, for the requested disaggregations, different time periods are used. For analysis by sex, cancers diagnosed from 1998 to 2004 were used. For analysis by remoteness, cancers diagnosed from 1997 to 2004 were used and for analysis by socioeconomic status cancers diagnosed from 2000 to 2004 were used. These years were selected based on the available information for constructing the life tables used in survival analysis. Changes in cancer survival usually occur gradually so the disparate time periods used in the indicator are unlikely to have a major impact on comparability.

The collation of cancer incidence data at cancer registries is a complex process which includes vetting data from numerous sources. The cancer registry processes ensure good quality data but to achieve this quality, a significant time lag between cancer diagnosis and finalisation of an incident case in the cancer registry transpires. Once data are supplied to the AIHW, cancer diagnoses which have been reported to more than one jurisdiction are identified and the data adjusted accordingly. This ensures a high quality national cancer incidence dataset. The time from cancer diagnosis to availability at the national level is approximately three years.

Calculation of five year survival also requires passing of an adequate time period for follow-up. For this analysis the follow-up period was to the end of 2006.

Accessibility:Help on this termThe AIHW with the assistance of the AACR and funding from Cancer Australia has published these data in Cancer survival and prevalence in Australia: cancers diagnosed from 1982 to 2004. This report is available on the AIHW website where it can be downloaded and printed without charge. Hard copies are also available for purchase from the AIHW.
Interpretability:Help on this term

Calculation of relative survival is complex and the concept may be confusing to some users. Information on how relative survival has been calculated and how to interpret it is available in the publication Cancer survival and prevalence in Australia: cancers diagnosed from 1982 to 2004. Information on all of the AIHW held data sets (ACD, NMD & NDI) is available on the AIHW website. Information on ABS data is available on the ABS website. Extensive information is also available on cancer coding and interpretation of cancer data be searched both electronically and in hard copy.

Relevance:Help on this term

The data used to calculate this PI at the national level are of high quality. While it is possible to calculate relative survival using different methods, the method used to calculate the indicator this year is adequate for reporting against the indicator at the national level.

Accuracy:Help on this term

Inaccurate responses may occur in all data provided to the AIHW, and the AIHW does not have direct access to data held by cancer registries, ABS or RBDM to determine the accuracy of the data provided. However, each of these data sources has broad population coverage and local data checking and validation processes leading to high quality data. In addition, the AIHW undertakes extensive validations on receipt of data. Data are checked for compliance with data definitions, 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.  Registries continually update their historical data in the light of new information (such as when a new pathology report or a death notification triggers a revision of old information) and when AIHW is advised of such changes, these are incorporated in the ACD leading to slight changes over time.

Errors may occur during the processing of data by the states and territories or at the AIHW. Processing errors prior to data supply may be found through the validation checks applied by the AIHW. This PI is calculated on data that have been reported by the AIHW. Prior to publication, the results of analysis are referred back to jurisdictions for checking and clearance. Any errors found by jurisdictions are corrected once confirmed. The AIHW does not adjust the data to correct for missing or incorrect values unless agreed by the jurisdiction supplying the data. Where errors are found post publication, the AIHW corrects as soon as possible, with resubmission of data by the affected states or territories as required.

Other factors which may affect accuracy are:

  • For analyses by remoteness and socioeconomic status, there may be differences in the definition for ‘usual residence’. Census data are rigorous when applying the definition for ‘usual residence’. However, mortality data may use the place that clients are living at the time of their treatment. It is common for people from remote and outer regional areas to move to major centres at the time of treatment for a significant illness. This will result in them being reported for example as ‘Major cities’ in death data, but as ‘Remote’ in census counts. The discrepancy becomes evident when comparing mortality rates, which may be lower in very remote areas and inconsistent with the population age structure from census estimates. The poorer outcome for more remote localities could be a significant underestimate of the true discrepancy, particularly in small jurisdictions.
  • For the denominator, 2005 survival probabilities of the general population were used as proxies for the 2006 survival probabilities, as 2006 mortality data were not available at the time of calculation.
Coherence:Help on this termThe information presented is consistent with that published in Cancer survival and prevalence in Australia: cancers diagnosed from 1982 to 2004.

Source and reference attributes

Submitting organisation:Help on this termAustralian Institute of Health and Welfare

Relational attributes

Related metadata references:Help on this term

Has been superseded by National Healthcare Agreement: PI 44-Survival of people diagnosed with cancer, 2012 QS Health, Superseded 14/01/2015

My items Help on this term
Download Help on this term