About asthma and associated comorbidities

Comorbidity

Some people with asthma 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 (the index disease). For people with asthma, having a comorbid chronic condition can have important implications for their health outcomes, quality of life and treatment choices.

Australians diagnosed with one or more chronic conditions often have complex health needs, die prematurely and have poorer overall quality of life (AIHW 2018). In terms of comorbidities, in 2017─18 one in five Australians (20%) had two or more chronic conditions (ABS 2018). The chance of developing chronic conditions increases with age, and since asthma often starts early in life, people with asthma are likely to develop another chronic condition during their lifespan (AIHW 2019).

The chronic conditions that have been selected for this asthma comorbidity analysis are: arthritis, back problems, cancer, chronic obstructive pulmonary disease (COPD), diabetes, heart, stroke and vascular disease, kidney disease, mental and behavioural conditions and osteoporosis. They have been selected because they are common in the general community, pose significant health problems and have been the focus of ongoing national surveillance efforts and action can be taken to prevent their occurrence (AIHW 2019). Other chronic conditions that are commonly found in people with asthma, and that can impact on asthma, include obesity, allergic rhinitis, obstructive sleep apnoea, and gastro-oesophageal reflux disease (Boulet 2009; Caughey et al. 2008; Cazzola et al. 2012).

The National Asthma Strategy 2018 (the Strategy) was launched in January 2018. The Strategy ‘aims to outline Australia’s national response to asthma and inform how existing limited health care resources can be better coordinated and targeted across all levels of government’ (Department of Health 2017). The Strategy identifies the most effective and appropriate interventions to reduce the impact of asthma in the community and continue to be an international leader in asthma prevention, management and research (Department of Health 2017). The Strategy notes that ‘the presence of one or more comorbid conditions in people with asthma is likely to compromise their quality of life and may complicate their management of asthma’ (Department of Health 2017). The AIHW has monitored and reported on the outcome measures associated with The Strategy by reporting on the 10 national asthma indicators. For more information, see National asthma indicators – an interactive overview and National Asthma Strategy 2018.

Treatment and management

Management of asthma includes medicines to minimise symptoms such as shortness of breath, wheezing and coughing, and to reduce the risk of adverse outcomes, such as flare-ups (AIHW 2019).

Treatment of comorbidities depends on individual patient needs. As recommended in the Australian Asthma Handbook, some comorbidities such as obesity, mental illness, allergic rhinitis and obstructive sleep apnoea, should be treated not only to improve patient health outcomes, but to also reduce their impact on asthma control and risk of flare‑ups (National Asthma Council Australia 2019).

Medications prescribed for some comorbidities may interact with one another, which can cause problems for people with asthma. One example is beta-blockers, a treatment sometimes used for cardiovascular disease, glaucoma or anxiety. In people with asthma, beta-blockers given by tablet or eye-drops can cause severe asthma flare-ups, requiring more intense treatment and management (AIHW 2019). Another example is non-steroidal anti-inflammatory medications (NSAIDs) including aspirin, which may be used to treat cardiovascular disease or arthritis. These medications can cause severe flare-ups in around 7% of people with asthma (Rajan et al. 2015).

For patients who have both asthma and COPD, treatment usually includes inhaled corticosteroids (anti-inflammatory medications) and long-acting bronchodilators together with management of modifiable risk factors (such as smoking cessation and increasing physical activity), pulmonary rehabilitation, and influenza vaccinations (National Asthma Council Australia 2019). Short-acting bronchodilators are also to be used as needed for symptom relief.

Due to the potential for interactions between different chronic conditions and the medications used to treat them, it is important that people with asthma tell their doctor(s) about any other conditions that they have, and any other treatment they are taking, so that their health can be carefully monitored.