People with chronic respiratory conditions often have other chronic and long-term conditions. This is called ‘comorbidity’, which describes any additional disease that is experienced by a person with a disease of interest.
In the 2017–18 NHS, for people aged 45 and over with:
There is an increasing recognition that asthma and COPD may occur together. Overall, about 20% of patients with obstructive airway disease have been diagnosed with both asthma and COPD (Gibson and MacDonald 2015).
Impact of natural events on chronic respiratory conditions
Natural events such as natural disasters or extreme weather changes can affect human health drastically, and those events that affect the air quality can have a direct impact on chronic respiratory conditions. The two natural events that affected chronic respiratory conditions in the recent times are thunderstorm asthma and the bushfires of 2019–20.
Thunderstorm asthma can occur suddenly in spring or summer when there is a lot of pollen in the air and the weather is hot, dry, windy and stormy. People with asthma and/or hay fever need to be extra cautious to avoid flare-ups induced by thunderstorm asthma between September and January in Victoria, New South Wales and Queensland because it can be very serious (National Asthma Council Australia 2019). In 2016, a serious thunderstorm asthma epidemic was triggered in Melbourne when very high pollen counts coincided with adverse meteorological conditions, resulting in 3,365 people presenting at hospital emergency departments over 30 hours, and 10 deaths (Thien et al. 2018). Following this event, a thunderstorm asthma forecasting system has been developed to give Victorians early warning of possible epidemic thunderstorm asthma events in pollen season (Victoria State Government 2022). See Natural environment and health.
Australian bushfires of 2019–20
The bushfires that swept across Australia in 2019–20 resulted in 33 deaths, destruction of over 3,000 houses and millions of hectares (Parliament of Australia 2020). Bushfire smoke exposure was significantly associated with an increased risk of respiratory morbidity (Liu et al. 2015). Nationally, hospitalisation rates increased for asthma and COPD coinciding with increased bushfire activity during the 2019–20 bushfire season (AIHW 2021b). For asthma, the highest increase was 36% in the week beginning 12 January 2020 (2.4 per 100,000 persons) compared to the previous 5-year average (1.7 per 100,000 persons). For COPD, the highest increase was 30% in the week beginning 1 December 2019 (2.0 per 100,000 persons) compared to the previous 5-year average (1.6 per 100,000 persons).
For Emergency Department presentations, asthma saw the highest increase of 44% in the week beginning 12 January 2020 (4.7 per 100,000 persons compared to the previous bushfire season (3.3 per 100,000 persons), while COPD saw the largest increase of 31% in the week beginning 12 January 2020 (1.4 per 100,000 persons) compared to the previous bushfire season (1.1 per 100,000 persons). See Natural environment and health.
In 2020, COPD was the fifth leading underlying cause of death in Australia, with 6,311 deaths (3.9% of all deaths) (AIHW 2022a). The trend in the previous 11 years shows that the age-standardised COPD death rate for people aged 45 and over fluctuated; the year 2014 had the highest COPD death rate at 70 deaths per 100,000 population, and the year 2020 saw a sharp drop making it the lowest death rate in the past 11 years (53 deaths per 100,000 population) (Figure 3). For more information on COPD deaths see Causes of death.
Death rates from all respiratory diseases combined showed a substantial fall in 2020, with rates particularly low for females and during the winter months compared with previous years. This is discussed in detail in ‘Chapter 2 Changes in the health of Australians during the COVID-19 period’ in Australia’s health 2022: data insights.
During the COVID-19 pandemic (as at 31 March 2022), 17.4% of COVID-19 related deaths due to pre-existing conditions was contributed to by chronic respiratory conditions, the fourth highest of all chronic conditions. In addition, higher than expected deaths were observed for chronic lower respiratory conditions in 2021. For more information see ‘Chapter 1 The impact of a new disease: COVID-19 from 2020, 2021 and into 2022’ in Australia’s health 2022: data insights.