Web update: Incidence of selected cancers in 2006–2010 presents statistics about local cancer incidence rates. Information is available for all cancers combined, as well as the following cancers; breast, cervical, prostate, colorectal, lung and melanoma of the skin. Results are presented for the 31 Primary Health Network (PHN) areas that cover Australia and for more than 300 smaller local areas called Statistical Areas Level 3 (SA3s), as defined by the Australian Bureau of Statistics (ABS).
This technical note summarises indicator specifications and methods used to calculate results presented in the Web update: Incidence of selected cancers in 2006–2010 on www.myhealthycommunities.gov.au.External link, opens in a new window.[http://www.myhealthycommunities.gov.au]
The Australian Cancer Database
Data for the web update were sourced from the 2012 Australian Cancer Database (ACD), compiled by the Australian Institute of Health and Welfare (AIHW). Incidence data are presented for 2006 to 2010 because at the time of creation, 2010 was the most recent year for which actual data were available for all states and territories.
All Australian states and territories have legislation that makes cancer a notifiable disease (with the exception of basal and squamous cell carcinomas of the skin (BCCs and SCCs)). Various institutions such as hospitals, pathology laboratories and registries of births, deaths and marriages must report cancer cases and deaths to their jurisdictional cancer registry. Each registry supplies cancer incidence data annually to the AIHW under an agreement between the registries and the AIHW. These data are checked, standardised and compiled into the ACD, the only repository of national cancer incidence data.
The ACD records all primary cancers, except for BCCs and SCCs which are not collected by the state and territory cancer registries. For more information, see the Data quality statement for the 2012 ACD, available online at http://meteor.aihw.gov.au/content/index.phtml/itemId/624388.External link, opens in a new window.[http://meteor.aihw.gov.au/content/index.phtml/itemId/624388]
About the measure
The measure used to describe cancer incidence is outlined in the indicator specification. The incidence data refer to the number of new cases diagnosed in 2006–2010, rather than the number of people newly diagnosed (because one person can be diagnosed with more than one cancer in a year), though the numbers are likely to be similar. The new cases in this incidence data include only primary cases (i.e. a tumour that is at the site where it was first formed, rather than a metastasis/ secondary cancer).
About the method
The web update includes measures expressed as age-standardised rates per 100,000 population. Age-standardised rates are hypothetical rates that would have been observed if the populations studied had the same age distribution as the standard population.
The direct method of age-standardisation was applied to the data. Age-standardised rates were derived by calculating crude rates by five year age groupings of 0–4 years to 85+ years. These crude rates were then given a weight that reflected the age composition of the standard population. The current standard population is the ABS Estimated Resident Population for Australia as at 30 June 2001. The method for calculating age-standardised rates for Primary Health Network areas and Statistical Areas Level 3 was the same.1
Presentation of results
The web update presents information at the geography of:
- Primary Health Network (PHN) areas – 31 geographic areas covering Australia, with boundaries defined by the Australian Government Department of Health
- Statistical Areas Level 3 (SA3s) – 333 geographic areas covering Australia, with boundaries defined by the ABS.2
National incidence rates for each of the selected cancers are also included for context.
Cancer incidence rates at PHN area and SA3 level were compiled by applying a geographic concordance to the ACD unit record data. The concordance used the Statistical Area Level 2 (SA2) of the residential address as recorded on the ACD.
Where an SA2 boundary overlapped a PHN area, records were attributed to a PHN area on the percentage of the population within that SA2 that fell within each PHN area. Figures were rounded at the end of the calculations to avoid truncation error.