Chronic respiratory conditions

Chronic obstructive pulmonary disease

This analysis is based on data only for people aged 45 and over. This age group was selected because the development of COPD occurs over many years and therefore mainly affects older people, and positive responses to the questions about ‘bronchitis and/or emphysema’ in the National Health Survey (NHS) from younger people are more likely to include more cases of acute bronchitis or asthma than COPD itself.

The risk factor data presented here were obtained at one point in time, based on self‑reported data from the NHS (with the exception of BMI, which was measured). When interpreting self-reported data, it is important to recognise that it relies on respondents providing accurate information.

It is not possible to attribute cause and effect to self-reported risk factors (and measured) and COPD. Risk factors present at the time of the survey may or may not have contributed to the presence of COPD. Similarly, the presence of COPD may not be directly related to the number of risk factors a person has.

National Health Survey

The National Health Survey (NHS) uses three factors to determine whether or not a person is counted as having a particular condition: whether the condition is current, whether it is long term and whether it was medically diagnosed. The combination of these factors required for a person to count as having the condition varies according to nature of the condition. For example, some conditions, such as diabetes and HSVD, once diagnosed, are seen to be lifelong. Even if a person no longer reports symptoms, they still count as having the condition. While other conditions, such as depression, asthma, cancer or back problems, can be lifelong, episodic or in complete remission.

Most conditions do not need the respondent to have been diagnosed by a doctor or nurse. The respondent is counted if they said they have the condition. However, in cases where the respondent said they had diabetes or HSVD and that the condition was not current, they need to have received a diagnosis to be counted.

Note: Please see the 2017-18 NHS User Guide for more information on the definitions of the conditions.

The risk factor definitions used in the ABS 2017–18 National Health Survey are described below.

Definitions for risk factors in the National Health Survey

Smoker status

Refers to the frequency of smoking of tobacco, including manufactured (packet) cigarettes, roll-your-own cigarettes, cigars and pipes, but excluding chewing tobacco, electronic cigarettes (and similar) and smoking of non-tobacco products. Categorised as:

Source: ABS 2018b.

Physical activity

Australia’s Physical Activity and Sedentary Behaviour Guidelines (the Guidelines) are a set of recommendations outlining the minimum levels of physical activity required for health benefits, as well as the maximum amount of time one should spend on sedentary behaviours to achieve optimal health outcomes (Department of Health 2019). Please see the Physical activity web topic page for more information.

In 2017–18, the ABS National Health Survey collected information for the first time on physical activity at work. Therefore, all results for adults include physical activity at work.

Based on the guidelines, insufficient physical activity is defined as:

• Adults aged 18–64 who did not complete 150 minutes of moderate to vigorous physical activity across 5 or more days in the last week
• Adults aged 65 and over who did not complete at least 30 minutes of physical activity per day on 5 or more days in the last week.

For the purpose of calculating activity time, vigorous activity time is multiplied by a factor of two.

Muscle strengthening activities are not included in this analysis.

Source: AIHW 2019d.

Body mass index

Body mass index (BMI) is a simple index of weight-for-height that is commonly used to classify underweight, normal weight, overweight and obesity. It is calculated from height and weight information, using the formula weight (kg) divided by the square of height (m). To produce a measure of the prevalence of underweight, normal weight, overweight or obesity in adults, BMI values are grouped according to the table below.

In 2017─18, 33.8% of respondents aged 18 years and over did not have a measured BMI. For these respondents, imputation was used to obtain BMI (ABS 2019b).

Sources: ABS 2018b; ABS 2019b.

National Hospital Morbidity Database

Chronic conditions in the AIHW National Hospital Morbidity Database (NHMD) are identified based on codes from the ICD-10-AM. For this report, the codes used can be found in Table 2 below. For NHMD analysis, hospitalisations for which the care type was reported as Newborn (without qualified days), and records for Hospital boarders and Posthumous organ procurement have been excluded.