Asthma and associated comorbidities: the numbers

Number of comorbid chronic conditions in people with asthma

An estimated 2.5 million Australians (10.8% of the total population) currently have asthma, based on self-reported data from the 2014–15 National Health Survey [1]. Of these, around 1.4 million people (6.2% of the total population) also had one or more of the following selected chronic conditions:

  • arthritis
  • back problems
  • cancer
  • cardiovascular disease/diseases of the circulatory system (CVD)
  • chronic obstructive pulmonary disease (COPD)
  • diabetes
  • mental health problems.

These 7 chronic conditions have been selected because they are common in the general community, pose significant health problems, have been the focus of ongoing national surveillance efforts, and action can be taken to prevent their occurrence.

Asthma affects people of all ages; however, many of the people with asthma and comorbid conditions are older Australians, reflecting the fact that chronic conditions are more widespread in older age groups.

Additional chronic conditions that are commonly found in people with asthma, and that can impact on asthma, include allergic rhinitis, obesity, obstructive sleep apnoea, nasal polyps (soft, painless, non-cancerous growths) and gastro-oesophageal reflux disease.

Of those who reported asthma, 42.4% had asthma only, and 57.5% had at least one other of the selected 7 chronic conditions (Figure 1). Over 1 in 4 (27.2%) had one other chronic condition, 13.8% had 2, and 16.5% had 3 or more other chronic conditions [2].

Figure 1: Comorbidity of selected chronic conditions in people with asthma, 2014–15

figure1-numbers-asthma-comorbities

Note: The 7 selected chronic conditions were mental health, arthritis, back problems, cardiovascular disease, COPD, diabetes and cancer.

Source: ABS National Health Survey, 2014–15 (First results and customised report ABS 2016) (Data table).

Types of comorbid chronic conditions in people with asthma

Among people with asthma:

  • 28.5% reported mental and behavioural problems (compared with 16.2% among people without asthma)
  • 22.5% reported CVD (compared with 17.8% among people without asthma)
  • 22.2% reported arthritis (compared with 14.5% among people without asthma) (Figure 2).

Figure 2: Prevalence of other chronic conditions in people with and without asthma, 2014–15

Vertical bar chart showing (with asthma; without asthma); prevelance of other chronic conditions on the x axis; percent (0 to 40) on the y axis.

Note: Proportions do not total 100% as one person may have more than one additional diagnosis.

Source: ABS National Health Survey, 2014–15 (First results and customised report ABS 2016) (Data table).

Asthma comorbidities by age

The prevalence of other chronic conditions in people with asthma varies with age.

Among younger people (aged 0–44) with asthma:

  • 25.5% reported mental and behavioural problems
  • 16.0% reported back problems
  • 7.3% reported CVD.

Younger people (aged 0–44) with asthma, compared to those without asthma of the same age, were:

  • 2.4 times as likely to report arthritis
  • 1.7 times as likely to report mental and behavioural problems (Figure 3).

Figure 3: Prevalence of other chronic conditions in people aged 0–44 with and without asthma, 2014–15

figure1-numbers-asthma-comorbities

Notes

  1. Proportions do not total 100% as one person may have more than one additional diagnosis.
  2. COPD statistics is not reported for this age group as this condition is not likely to affect younger population

Source: ABS National Health Survey, 2014–15 (First results and customised report ABS 2016) (Data table).

Among people aged 45–64 with asthma:

  • 40.7% reported arthritis
  • 37.2% reported mental health problems.
  • 36.8% reported cardiovascular disease.

People aged 45–64 with asthma, compared to those without asthma of the same age, were:

  • 6.9 times as likely to report COPD
  • 1.7 times as likely to report arthritis
  • 1.6 times as likely to report diabetes (Figure 4).

Figure 4: Prevalence of other chronic conditions in people aged 45–64 with and without asthma, 2014–15

figure1-numbers-asthma-comorbities

Note: Proportions do not total 100% as one person may have more than one additional diagnosis.

Source: ABS National Health Survey, 2014–15 (First results and customised report ABS 2016) (Data table).

Among older people (aged 65 and over) with asthma:

  • 63.4% reported cardiovascular disease
  • 59.6% reported arthritis
  • 37.3% reported back problems.

Older people (aged 65 and over) with asthma, compared to those without asthma of the same age, were:

  • 4.8 times as likely to report COPD
  • 1.5 times as likely to report back problems
  • 1.4 times as likely to report mental and behavioural problems (Figure 5).

Figure 5: Prevalence of other chronic conditions in people aged 65 and over with and without asthma, 2014–15

figure1-numbers-asthma-comorbities

Note: Proportions do not total 100% as one person may have more than one additional diagnosis.

Source: ABS National Health Survey, 2014–15 (First results and customised report ABS 2016) (Data table).

Data notes

The comorbidity data presented here are based on self-reported data from the NHS. When interpreting self-reported data, it is important to recognise that because we rely on respondents providing accurate information, the outputs may not always be a true reflection of the situation.

In the 2014–15 NHS, the number and proportion of persons with long-term health conditions is presented as those who have "a current medical condition which has lasted, or is expected to last, for 6 months or more, unless otherwise stated" (ABS 2015). For all of the chronic conditions included in this analysis except for back problems and COPD the NHS participants were asked whether they have long-term health conditions diagnosed by a doctor or nurse. The respondents were not asked whether they were told they had back problems or COPD by a doctor or nurse. This difference in the questions may affect the estimated prevalence of the conditions.

References

  1. Australian Bureau of Statistics (ABS) 2015. National Health Survey: First Results, 2014–15. ABS Cat. no. 4364.0.55.001. Canberra: ABS.
  2. ABS 2016. National Health Survey 2014–15 (customised report). Canberra: ABS.