Older Australia at a glance

Burden of disease (BoD) is a standard method for analysis of the causes of health loss. BoD measures the impact of fatal burden (the impact from dying prematurely measured by years of life lost) and non-fatal burden (the burden from living with ill-health measured by years lived with disability) of diseases and injuries to provide an estimate of a population’s health and the attribution of risk factors to the total disease burden.

BOD analysis provides a quantifiable measure of total burden—the disability-adjusted life year (DALY) that allows for diseases and risk factors to be ranked in terms of their contribution to the overall disease burden. One DALY represents 1 lost year of ‘healthy life’ due to premature death, or living with ill health or disability or a combination of these factors. A DALY is a combination of the years of life lost (YLL or fatal burden) due to premature death and years of life lived with ill health or disability (YLD or non-fatal burden) [1].

The results discussed in this section use data from the 2011 Australian Burden of Disease Study. To learn more about the methodology applied to burden of disease analysis, please refer to Australian Burden of Disease Study 2011: methods and supplementary material.

Total burden in the older Australian population

Overall, older Australians (Australians aged 65 and over) lost more than 1.8 million DALY due to premature death or living with a disease in 2011, equating to around 600 DALY per 1,000 people. The burden was largely due to premature death (over 1.1 million YLL) which accounted for 63% of the total burden, as opposed to years lived with disability which contributed to 37% of the burden (around 700,000 YLD) [1].

Total burden by age

The burden was highest for 65–69 year olds (around 360,000 DALY), and remained relatively constant at this level before decreasing with age from 85–89 year olds (down to approximately 4,200 DALY for those aged 100 and over). In contrast, the rate of burden (that is the DALY rate per 1,000 people) increased progressively with age from 376 per 1,000 people aged 65–69 years to 1,388 per 1,000 people aged 100 and over (Figure 1).

Total burden by sex

The burden was spread relatively evenly between the sexes with men accounting for just over half (51%) of the burden (women accounted for 49%). Men experienced more burden than women between the ages of 65 and 84 years (around 780,000 DALY compared with 630,000 DALY), whereas women experienced more burden than men from the age of 85 and over (270,000 DALY compared with 170,000 DALY). Among men, the burden was highest for 65–69 year olds (209,000 DALY), with the number of YLL and YLD decreasing with age. For women, the burden was highest among 80–84 year olds (175,000 DALY) (Figure 2).

Leading causes of burden of disease: disease group

Cardiovascular disease and cancer were the leading causes of burden for older Australians (contributing 24% of total DALY, each) followed by neurological conditions (11%), musculoskeletal conditions, and respiratory conditions (9%, each).
Among these top disease groups, the rate of burden per 1,000 people increased with age—except for cancer, where the rate was highest for 80–84 year olds.

The leading causes of burden were the same for men and women with only the order differing between them.

• For men, the leading cause was cancer and other neoplasms (28%), followed by cardiovascular disease (25%), respiratory diseases (9%), neurological conditions (8%) and musculoskeletal diseases (7%).
• Cardiovascular disease was the leading cause in women (23%), followed by cancer and other neoplasms (20%), neurological conditions (13%), musculoskeletal conditions (11%) and respiratory diseases (9%) (Figure 3).

Fatal and non-fatal component of total burden

Overall, fatal burden contributed to a larger component of total burden than non-fatal burden (63% and 37%, respectively). Cancer had the largest fatal component of all disease groups (93%), followed by infections (84%) and cardiovascular diseases (79%) (Figure 4). Respiratory diseases had the most even split between the fatal and non-fatal component, while the burden due to hearing and vision disorders was all non-fatal.

Distribution by sex

As established earlier, the total burden experienced in Australia in 2011 was distributed relatively evenly between men (51%) and women (49%). There were differences, however, in the distribution of burden by disease group between men and women (Figure 5):

• The difference was greatest for reproductive and maternal conditions which were unsurprisingly higher for women by 78 percentage points.
• Neurological conditions were 20 percentage points higher for women than men (60% and 40%, respectively).
• Men had a higher proportion of the burden due to cancer and other neoplasms than women (59% and 41%).
• The burden of gastrointestinal diseases was distributed evenly between men and women.

Differences by sex

Rate ratios and rate differences of the age-standardised rates (ASR) of disease burden (DALY rates per 1,000) were evaluated to determine the difference in the rate of burden between men and women (Table 1). The overall rate ratio between men and women was 1.4, meaning men experienced burden at a rate 40% higher than women. There were further differences between the sexes by disease group:

• Men had 1.8 times the burden due to injuries.
• Men were 1.7 times as likely to experience burden due to cancer and other neoplasms.
• Men had 1.6 times the burden of cardiovascular diseases.
• Women experienced higher rates for oral disorders, musculoskeletal conditions, and unsurprisingly reproductive and maternal conditions, although the rate differences of these were relatively small.
• There were no differences in the rate of burden for neurological conditions or skin disorders.
• Cancer and other neoplasms and cardiovascular diseases accounted for a large amount of the rate difference between men and women.

Table 1: Comparison of age-standardised DALY rates, rate differences and rate ratios between men and women aged 65 and over, by disease groups, 2011

Disease group	ASR: men(a)	ASR: women(a)	Rate difference	Rate ratio
Blood & metabolic disorders	6.9	5.9	1.0	1.2
Cancer & other neoplasms	187.5	108.8	78.7	1.7
Cardiovascular diseases	174.3	111.4	62.9	1.6
Endocrine disorders	25.3	16.4	8.9	1.5
Gastrointestinal diseases	19.8	15.4	4.3	1.3
Hearing & vision disorders	21.4	17.6	3.8	1.2
Infant & congenital conditions	0.9	0.7	0.2	1.3
Infectious diseases	11.2	7.4	3.8	1.5
Injuries	24.7	13.9	10.9	1.8
Kidney & urinary diseases	17.5	11.2	6.3	1.6
Mental & substance use disorders	11.6	11.0	0.7	1.1
Musculoskeletal conditions	49.3	60.3	–11.0	0.8
Neurological conditions	59.0	61.0	–2.0	1.0
Oral disorders	10.8	11.5	–0.7	0.9
Reproductive & maternal conditions	0.4	3.0	–2.5	0.1
Respiratory diseases	61.1	46.3	14.7	1.3
Skin disorders	4.7	4.6	0.1	1.0
Total (DALY)	686.5	506.4	180.0	1.4

(a) Rates are age-standardised to the 2001 Australian Standard Population and are expressed per 1,000 people. The base for calculating rate differences and rate ratios is males.

Source: AIHW [2].

Leading causes of burden of disease: individual diseases

At the individual disease level, coronary heart disease was the leading cause of burden for older Australians, followed by dementia and chronic obstructive pulmonary disease (COPD). The top 10 individual diseases for older Australians accounted for over half (51%) of the total burden (Table 2).

While coronary heart disease remained the leading cause of burden for men and women, there were some differences between the sexes

• In men, coronary heart disease was the leading cause of disease burden accounting for 14% of the total burden, followed by COPD (6.5%) and lung cancer (5.8%).
• In women, coronary heart disease accounted for 11% of the burden, followed by dementia (10%) and stroke (6.3%).
• The age standardised rate of burden due to coronary heart disease was 99 per 1,000 men compared with 52 per 1,000 women. As such, men had 1.9 times the burden of coronary heart disease as women.

Age patterns

The leading causes of burden for men and women differed by age (Figure 7 and 8). A notable pattern was evident for both sexes, whereby the rate of burden from neurological conditions increased with age. For example, dementia was not one of the top 10 leading diseases for men or women aged 65–69 years, however from the age of 70 onwards it remained as one of the leading causes of burden for both men and women with its rank within the top 10 leading diseases differing by age group. Furthermore, the rate of total burden due to dementia increased with age for both sexes—from 16 to 219 per 1,000 men aged 70–74 and 100 years and older, respectively, and from 18 to 319 per 1,000 women of the same age range (Figure 6).

Table 2a: Top 10 diseases causing burden in persons aged 65 years and over, DALY number and proportion of DALY total, 2011

Rank	Condition	DALY	% of total
1	Coronary heart disease	233,731	12.7
2	Dementia	142,091	7.7
3	COPD	113,732	6.2
4	Stroke	103,296	5.6
5	Lung cancer	87,928	4.8
6	Diabetes	60,779	3.3
7	Other musculoskeletal	60,708	3.3
8	Bowel cancer	53,222	2.9
9	Hearing loss	43,184	2.3
10	Osteoarthritis	41,241	2.2
	Top 10 diseases	939,911	51.0
	All other diseases	903,391	49.0
	Total	1,843,302	100.0

Table 2b: Top 10 diseases causing burden in men aged 65 years and over, DALY number and proportion of DALY total, 2011

Rank	Condition	DALY	% of total
1	Coronary heart disease	135,617	14.3
2	COPD	61,533	6.5
3	Lung cancer	55,058	5.8
4	Dementia	50,808	5.4
5	Stroke	46,836	5.0
6	Prostate cancer	40,029	4.2
7	Diabetes	34,228	3.6
8	Bowel cancer	30,748	3.3
9	Other musculoskeletal	26,934	2.8
10	Hearing loss	21,404	2.3
	Top 10 diseases	503,195	53.2
	All other diseases	441,928	46.8
	Total	945,123	100.0

Table 2c: Top 10 diseases causing burden in women aged 65 years and over, DALY number and proportion of DALY total, 2011

Rank	Condition	DALY	% of total
1	Coronary heart disease	98,114	10.9
2	Dementia	91,283	10.2
3	Stroke	56,460	6.3
4	COPD	52,198	5.8
5	Other musculoskeletal	33,775	3.8
6	Lung cancer	32,870	3.7
7	Osteoarthritis	27,711	3.1
8	Diabetes	26,551	3.0
9	Breast cancer	25,427	2.8
10	Bowel cancer	22,473	2.5
	Top 10 diseases	466,862	52.0
	All other diseases	431,316	48.0
	Total	898,178	100.0

Source: AIHW [2].

Burden of disease by location

Variation in disease burden can be affected by where a population lives. Burden was highest in Very remote areas and areas with low socio-economic status (SES).

Remoteness

Burden was greater in Very remote areas than Major cities, with the age-standardised rate (ASR) of burden increasing from 571 DALY per 1,000 people in Major cities to 871 per 1,000 people in Very remote areas (Table 3). This difference was largely driven by the rate of non-fatal burden in Very remote areas, which was almost twice as high as the rate in Major cities (396 and 216 YLD per 1,000, respectively). Non-fatal burden therefore contributed to a greater proportion of the total burden in Very remote areas (45%) than Major cities (37%).

Table 3a: Burden by remoteness area, numbers, rates and rate ratios, Australians aged 65 and over, 2011

Remoteness area	DALY (’000)	ASR	Rate ratio
Major cities	1,201	571.2	1.0
Inner regional	419	613.8	1.1
Outer regional	188	627.6	1.1
Remote	22	706.3	1.2
Very remote	11	871.2	1.5
Australia	1,841	588.5

Table 3b: Fatal burden by remoteness area, numbers, rates and rate ratios, Australians aged 65 and over, 2011

Remoteness area	YLL (’000)	ASR	Rate ratio
Major cities	751	355.4	1.0
Inner regional	268	392.1	1.1
Outer regional	123	410.4	1.2
Remote	14	431.8	1.2
Very remote	6	475.3	1.3
Australia	1,162	370.2

Table 3c: Non-fatal burden by remoteness area, numbers, rates and rate ratios, Australians aged 65 and over, 2011

Remoteness area	YLD (’000)	ASR	Rate ratio
Major cities	450	215.8	1.0
Inner regional	151	221.7	1.0
Outer regional	65	217.2	1.0
Remote	9	274.6	1.3
Very remote	5	395.9	1.8
Australia	680	218.3

Note: Rates are age-standardised to the 2001 Australian Standard Population and are expressed per 1,000 people. The base for calculating rate ratios is Major cities.

Source: AIHW [2].

The rate of burden progressively increased with remoteness and age, with a similar pattern by age across Major cities, Inner regional, Outer regional and Remote areas (Figure 9). The pattern in Very remote areas was different, with a slight plateau in the rate between 75–79 and 80–84 year olds (957 and 1,045 DALY per 1,000 people), before increasing sharply to 1,552 DALY per 1,000 people aged 85 and over. The rate ratio was highest for 75–79 year olds where the rate of burden in Very remote areas was 1.6 times that in Major cities. The difference between the burden in Very remote and Major cities was lowest for those aged 80–84 years (rate ratio of 1.4).

Socio-economic status

There was some difference in the burden experienced by people living in the lowest SES areas compared with those in the highest SES areas, with higher rates in the lowest areas (512 and 656 per 1,000 people, respectively). This difference was largely due to the higher rate of fatal burden in low SES areas, which was 1.3 times the rate in high SES areas. Accordingly, the proportion of total burden attributable to fatal burden was higher in low SES areas (65%) than high SES areas (60%) (Table 4).

Table 4a: Total burden by socio-economic status area, numbers, rates and rate ratios, Australians aged 65 and over, 2011

Socio-economic status area	DALY (’000)	ASR	Rate ratio
Q1 (lowest)	437	655.7	1.3
Q2	423	624.7	1.2
Q3	372	579.6	1.1
Q4	313	557.7	1.1
Q5 (highest)	298	511.5	1.0
Australia	1,844	589.4

Table 4b: Fatal burden by socio-economic status area, numbers, rates and rate ratios, Australians aged 65 and over, 2011

Socio-economic status area	YLL (’000)	ASR	Rate ratio
Q1 (lowest)	284	425.1	1.4
Q2	272	399.9	1.3
Q3	236	367.0	1.2
Q4	191	337.3	1.1
Q5 (highest)	179	307.0	1.0
Australia	1,162	370.4

Table 4c: Non-fatal burden by socio-economic status area, numbers, rates and rate ratios, Australians aged 65 and over, 2011

Socio-economic status area	YLD (’000)	ASR	Rate ratio
Q1 (lowest)	153	230.6	1.1
Q2	151	224.8	1.1
Q3	136	212.6	1.0
Q4	123	220.4	1.1
Q5 (highest)	118	204.5	1.0
Australia	682	219.0

Note: Rates are age-standardised to the 2001 Australian Standard Population and are expressed per 1,000 people. The base for calculating rate ratios is Q5 (highest).

Source: AIHW [2].

The rate of burden rose with increasing disadvantage and age. The rate ratio between the lowest and highest SES areas distinctly fell with increasing age. Rates in the lowest SES areas were 1.4 times as high as the rate in the highest SES areas for 65–69 year olds, falling to just 1.1 times the rate for those aged 85 and over (Figure 10).

The number of DALY for people aged 65 and over increased from 1.7 million to 1.8 million between 2003 and 2011. However, the overall rate of DALY was lower in 2011 than in 2003, falling from 667 to 597 per 1,000 people aged 65 and over.
The age-specific DALY rates show the rate of burden was lower in 2011 than in 2003 for those aged 65 through to 89 years of age and higher for those aged 95 and over (Figure 11). The number of DALY was higher in 2011 than in 2003 from the age of 80 years, indicating that the increase is largely due to increases in the ageing population (more people living longer).

After adjusting for differences in the population structure, the overall rate of burden between 2003 and 2011 decreased by 10%—from 663 to 589 per 1,000 people aged 65 and over.

References

1. AIHW (Australian Institute of Health and Welfare) 2016. Australian Burden of Disease Study: Impact and causes of illness and death in Australia 2011. Australian Burden of Disease Study series no. 3. BOD 4. Canberra: AIHW.
2. AIHW 2016. AIHW unpublished data from the Australian Burden of Disease Study 2011. Canberra: AIHW.