Loss of vision

Why is this an important indicator for diabetes?

Eye diseases such as retinopathy, cataracts and glaucoma are common in people with diabetes. Diabetic retinopathy is the leading cause of blindness in people aged 30–69 years. The risk of eye disease for people with diabetes rises with age and the duration of their diabetes. The risk rises even more if they have high blood pressure, high cholesterol, they smoke, or if they have kidney disease.

This indicator shows trends in the prevalence of long term vision loss among people with diabetes in:

• the general population
• Aboriginal and Torres Strait Islander people
• non-Indigenous people
• people of culturally and linguistically diverse backgrounds, and
• people living in different geographic areas.

What are the results?

General population

In 2007–08 almost 96,000 (10.7%) people with diabetes had long-term visual loss (Figure 1).

• In 2001, 15.3% of people with diabetes had long-term vision loss, compared to 13.8% in 2004–05 and 10.7% in 2007–08.

Figure 1: Prevalence of long-term visual loss among people with diabetes, 2001 to 2007–08

Note: Directly age standardised to the 2001 NHS diabetes population.

Sources: AIHW 2011 analysis of ABS NHS 2001, 2004–05 and 2007–08 (reissue).

Other population groups

In 2007–08:

• Over 19,000 (19%) people with diabetes living in outer regional and remote areas had long-term visual loss (Table 1). 7% of those living in inner regional areas had long-term vision loss, while 11% living in major cities had long-term vision loss.

• Over 43,000 (12%) people with diabetes born overseas had long-term visual loss. Only 9% of people with diabetes born in Australia had long-term vision loss.

Between 2001 and 2007–08, the prevalence of long-term visual loss changed among:

• People with diabetes who live in major cities (16% to 11%), inner regional areas (15% to 7%), and outer regional and remote areas (12% to 19%).
• People with diabetes who were born in Australia, from 17% to 9%. Rates of vision loss among people with diabetes who were born overseas remained relatively steady.

Between 2001 and 2004–05, rates of long-term vision loss among Aboriginal and Torres Strait Islander peoples with diabetes changed from 15% to 19%, while rates of long-term vision loss among non-Indigenous Australians with diabetes changed from 12% to 9%.

* These estimates have a relative error of 25–50% and should be used with caution.

Notes
1. Rates are for people with diabetes.
2. Directly age-standardised to the 2001 NHS diabetes population.
2. Indigenous rates are directly age-standardised to the 2001 NHS Indigenous diabetes population.
3. The ABS NHS excluded persons living in very remote areas of Australia.

Source: AIHW analysis of ABS NHS 2001, 2004–05 and 2007–08 NHS (Reissue), ABS NHS–IS 2001 and ABS NATSIHS 2004–05.

What are the data sources?

The main data sources are:

• The 2001, 2004–05, and 2007-08 (Reissue) Australian Bureau of Statistics (ABS) National Health Survey (NHS) (ABS cat. no. 4634.0).
• The ABS's National Health Survey – Indigenous Supplement (NHS–IS) 2001 (ABS cat. no. 4715.0), and
• The ABS's National Aboriginal and Torres Strait Islander Health Survey (NATSIHS) 2004-05 (ABS cat. no. 4715.0).

How is this indicator calculated?

The data in this indicator are directly age-standardised to the 2001 NHS diabetes population and presented as the number of cases of visual loss per 100 people with diabetes.

In each of these groups:

• the general population
• Aboriginal and Torres Strait Islander people
• non-Indigenous people
• people of culturally and linguistically diverse backgrounds
• people living in major cities, inner regional, and outer regional and remote areas

the rates compare

• numerator: the number of people with diabetes and long-term vision loss (from the NHS/NATSIHS), to
• denominator: the total number of people with diabetes (from the NHS/NATSIHS).

Are there any data limitations?

• These data come from self-reported responses to the surveys, which may lead to under- or over-reporting of diabetes and vision loss.
• Differences in collection methods between surveys affect the ways these data can be compared. Changes in public awareness of diabetes and vision loss over time may also affect this.
• Country of birth has been used as a proxy for cultural and linguistic diversity. This does not fully represent the complexity of cultural diversity in Australia.
• Data are currently not complete enough to allow analysis of differences between socio-economic groups..

Definitions

Diabetes is only included in this indicator if people have reported they have been told by a doctor or nurse that they have diabetes. It does not include females with gestational diabetes.

Country of birth has been defined based on the ABS NHS, as either Australian-born or overseas-born. Australian-born includes Australia, Norfolk Island and Australian External Territories. Overseas-born includes all other countries/regions and those that were not stated or inadequately described.

Geographic areas have been defined based on Accessibility/Remoteness Index of Australia (ARIA). Three categories are used in this indicator: 'Major cities of Australia', 'Inner regional Australia' and 'Outer regional or Remote Australia' (which is a combination of Outer regional and Remote Australia).

Indigenous status is self-reported.

Vision loss
Table 2 illustrates how vision loss has been defined for this indicator.

Where can I find more information?

AIHW 2007. National indicators for monitoring diabetes: report of the Diabetes Indicators Review Subcommittee of the National Diabetes Data Working Group. Diabetes series no. 6. Cat. no. CVD 38. Canberra: AIHW.

Abbreviations

ABS

Australian Bureau of Statistics

AIHW

Australian Institute of Health and Welfare

NATSIHS

National Aboriginal and Torres Strait Islander Health Survey

NHS

National Health Survey

NHS–IS

National Health Survey – Indigenous Supplement