Notes on the data: Chronic diseases and conditions
Estimated population, aged 18 years and over, with high blood cholesterol, 2011-12
Note: The indicators of chronic diseases and conditions have not been updated to reflect information in the 2014–15 National Health Survey. The modelling of these estimates has been held over until a final decision is made as to access by PHIDU to small area data considered to be highly relevant for use as small area predictors in the production of these estimates. For example, for the indicator of diabetes type 2, the MBS item for HbA1c and, for mental health conditions, anti-depressant medications from PBS both add strength to the available predictors. Work will proceed with the current predictors until these data is made available.
Policy context: Cholesterol is a type of fat that circulates in the blood. It is essential for many metabolic processes, including the production of hormones and building cells . Total cholesterol includes 'good' cholesterol (High Density Lipoprotein (HDL)), which prevent blockages in the circulatory system; 'bad' cholesterol (Low Density Lipoprotein (LDL)), which can leave fatty deposits in the arteries; and other lipid components . High levels of total cholesterol may increase the risk of cardiovascular disease.
- National Heart Foundation of Australia. Cholesterol [Internet]. 2013 [cited 2013 July 8]. Available from: http://heartfoundation.org.au/your-heart/know-your-risks/blood-cholesterol.
- National Heart Foundation of Australia and the Cardiac Society of Australia and New Zealand. Lipid Management Guidelines - 2001. MJA 2001; 175:Supplement.
Notes: In the absence of data from administrative data sets, estimates are provided for certain chronic diseases and conditions from the 2011–12 Australian Health Survey, conducted by the Australian Bureau of Statistics (ABS).
Estimates at the Population Health Area (PHA) are modelled estimates produced by the ABS, as described below (estimates at the Local Government Area (LGA) and Primary Health Network (PHN) level were derived from PHA estimates).
Estimates for Quintiles and Remoteness Areas are direct estimates, extracted using the ABS Survey TableBuilder.
Users of these modelled estimates should note that they do not represent data collected in administrative or other data sets. As such, they should be used with caution, and treated as indicative of the likely social dimensions present in an area with these demographic and socioeconomic characteristics.
The numbers are estimates for an area, not measured events as are, for example, death statistics. As such, they should be viewed as a tool that, when used in conjunction with local area knowledge and taking into consideration the prediction reliability, can provide useful information that can assist with decision making for small geographic regions. Of particular note is that the true value of the published estimates is also likely to vary within a range of values as shown by the upper and lower limits published in the data (xls) and viewable in the bar chart in the single map atlases.
What the modelled estimates do achieve, however, is to summarise the various demographic, socioeconomic and administrative information available for an area in a way that indicates the expected level of each health indicator for an area with those characteristics. In the absence of accurate, localised information about the health indicator, such predictions can usefully contribute to policy and program development, service planning and other decision-making processes that require an indication of the geographic distribution of the health indicator.
The survey response rate of around 85% provides a high level of coverage across the population; however, the response rate among some groups is lower than among other groups, e.g., those living in the most disadvantaged areas have a lower response rate than those living in less disadvantaged areas. Although the sample includes the majority of people living in households in private dwellings, it excludes those living in the most remote areas of Australia; whereas these areas comprise less than 3% of the total population, Aboriginal people comprise up to one third of the population in these areas. This and other limitations of the method mean that estimates have not been published for PHAs with populations under 1,000, or with a high proportion of their population in:
- non-private dwellings (hospitals, gaols, nursing homes - and also excludes members of the armed forces);
- in Very Remote areas;
- in discrete Aboriginal communities; and
- where the relative root mean square errors (RRMSEs) on the estimates was 1 or more (estimate replaced with ≠)
- Estimates with RRMSEs from 0.25 and to 0.50 have been marked (~) to indicate that they should be used with caution; and those greater than 0.50 but less than 1 are marked (~~) to indicate that the estimate is considered too unreliable for general use.
- For the Primary Health Network (PHN) data, differences between the PHN totals and the sum of LGAs within PHNs result from the use of different concordances.
Total cholesterol results were obtained for selected persons aged 12 years and over, who agreed to participate in the National Health Measures Survey (NHMS) component of the AHS and provided a blood sample. The total cholesterol test measures the combined amount of lipid (fat) components circulating in the blood at the time of the test. Fasting was not required. In the NHMS, the following definition for high serum total cholesterol was used: abnormal total cholesterol indicated by levels ≥ 5.5 mmol/L. This was based on epidemiological data and publications of major clinical trials, and advice from the National Heart Foundation Australia and the Cardiac Society of Australia and New Zealand. The data therefore refer to persons with a total blood cholesterol level ≥ 5.5 mmol/L.
Geography: Data available by Population Health Area, Local Government Area, Primary Health Network, Quintiles and Remoteness Areas
Numerator: Estimated number of people aged 18 years and over with high blood cholesterol
Denominator: Population aged 18 years and over
Detail of analysis: Indirectly age-standardised rate per 100 population (aged 18 years and over); and/or indirectly age-standardised ratio, based on the Australian standard
PHA, LGA & PHN: Compiled by PHIDU based on modelled estimates from the 2011-12 Australian Health Survey, ABS (unpublished).
Quintiles & Remoteness: Compiled by PHIDU based on direct estimates from the 2011-12 Australian Health Survey, ABS Survey TableBuilder.