Technical notes
Data source: Australian Institute of Health and Welfare National Mortality Database
Cause of Death Unit Record File data are provided to the Australian Institute of Health and Welfare (AIHW) by the Registrars of Births, Deaths and Marriages and the National Coronial Information System (managed by the Victorian Department of Justice and Community Safety) and include cause of death coded by the Australian Bureau of Statistics (ABS). The data are maintained by the AIHW in the National Mortality Database.
Analysis was performed by year of registration of death. Deaths registered in 2020 and earlier are based on the final version of cause of death data; deaths registered in 2021 are based on the revised version; deaths registered in 2022 and 2023 are based on the preliminary version. Revised and preliminary versions are subject to further revision by the Australian Bureau of Statistics.
Causes of death are based on underlying causes of death and classified using an AIHW-modified version of Becker R, Sivli J, Ma Fat, L'Hours A, Laurenti R. 2006. A method for deriving leading causes of death. Bulletin of the World Health Organization 84: 297–304.
For more information on the AIHW National Mortality Database, see Deaths data at AIHW.
The data quality statements underpinning the AIHW National Mortality Database can be found in the following ABS publications:
- ABS quality declaration summary for Deaths, Australia
- ABS quality declaration summary for Causes of death, Australia.
Data source: Australian Bureau of Statistics 2022 National Health Survey
In this section:
About the data and factors influencing disease estimates
The 2022 National Health Survey (NHS) was conducted by the ABS from January 2022 to April 2023. Data was collected from approximately 13,100 households around Australia. The survey collected a range of information about the health of Australians including the prevalence of long-term health conditions, health risk factors, demographic and socioeconomic characteristics and self-reported health status.
For further information on how the NHS data are collected, see ‘How the data is collected’ in the ABS 2022 National Health Survey methodology.
While the accuracy of estimates may vary across conditions self-reported to the NHS, these data importantly enable us to examine the co-occurrence of a wide range of long-term health conditions across the Australian population to produce estimates of multimorbidity. This is not possible using separate data sources.
The following sections provide more information on factors influencing disease estimates.
ABS 2022 NHS long-term health conditions: definitions and factors influencing disease estimates
A long-term health condition is defined in the NHS as a condition which was current at the time of interview and had lasted, or was expected to last, 6 months or more.
Information on long-term health conditions was collected using:
- condition-specific modules to capture detailed information on a selection of conditions associated with substantial health impacts: asthma, cancer, cardiovascular disease and diabetes.
- questions where respondents were prompted to review lists of conditions and identify each condition they had.
- an open-ended question to capture any other conditions not already captured.
The self-reported nature of the NHS data relies on survey respondents providing accurate information. Conditions that are not specifically prompted for, that are undiagnosed or asymptomatic in early stages are likely to be under-reported. Potential overdiagnosis of conditions may also affect results based on self-reported data.
Furthermore, an individual’s tendency to self-report a condition can differ based on characteristics such as their age and cultural background and will influence results. Whether a condition is self-reported may also be influenced by characteristics of the condition for example, whether it is episodic (such as migraine) or persistent in nature (such as diabetes).
NHS prevalence estimates based on self-reported information may therefore differ to estimates based on diagnostic surveys or surveys collecting biomedical samples (such as blood and urine) for testing.
Scope of the ABS 2022 NHS and influence on disease estimates
The ABS 2022 NHS is a community-based survey and does not include information from people living in residential aged care facilities, hospitals or prisons. This will exclude people likely to experience certain long-term health conditions such, as dementia, and may underestimate the prevalence of multimorbidity.
The NHS does not capture residents of Very remote areas and discrete First Nations communities. While this is unlikely to affect national estimates, it is not possible to report estimates of multimorbidity among First Nations people using the NHS.
For further information, see ‘Scope’ in the ABS 2022 National Health Survey methodology. For further information about chronic conditions among First Nations people, see National Aboriginal and Torres Strait Islander Survey 2022-23.
Conditions included in NHS multimorbidity estimates and how they are counted
A list of 72 selected long-term health conditions was used in analysis of ABS 2022 NHS data (Table 1). The 72 conditions are a subset of chronic conditions from the Australian Burden of Disease Study (ABDS) disease list (AIHW 2021) that could be reasonably identified in the 2022 NHS survey data.
The ABDS disease list was used as the conditions have been assessed to be of substantial burden to at least one age group or sex, or to be of significant policy interest. The list includes conditions commonly diagnosed among younger people, such as attention deficit hyperactivity disorder (ADHD), as well as conditions more common among older people such as deafness and hearing loss. This supports the analysis of multimorbidity among people of all ages.
The severity or impact of the 72 conditions may vary depending on the condition, condition severity or stage of progression. For example, asthma may be self-reported where it is mild, moderate or severe although it is not possible to distinguish these cases in the NHS data. Where possible, conditions that have been corrected, such as vision conditions corrected with glasses, are excluded from analysis. It was not possible to exclude hearing conditions corrected with hearing aids.
For more information on the selection and classification of diseases see, Australian Burden of Disease Study: Methods and supplementary material 2018.
Determining multimorbidity
The 72 conditions are counted individually to determine multimorbidity (whether a person has 2 or more conditions). For example, mental health conditions such as depression, anxiety and drug and alcohol use disorders are counted individually so that an individual with more than one of these long-term health conditions is considered to have multimorbidity.
Condition group multimorbidity
For analysis by condition group, groupings are based on the Australian burden of disease condition groups.
The 72 conditions are counted individually to determine multimorbidity in analysis by condition group so that people with 2 conditions in the same group are counted as having multimorbidity.
Condition group (prevalence) | Condition | NHS condition codes |
|---|---|---|
Cancer (2.3%) | Bowel or colorectal cancer | 110102 |
Brain cancer | 110110 | |
Breast cancer | 110107 | |
Cancer of female genital organs | 110108 | |
Cancer of male genital organs | 110109 | |
Cancer of other digestive organs | 110105 | |
Cancer site unknown | 110114 | |
Hodgkin's disease | 110111 | |
In situ neoplasms, benign neoplasms & neoplasms of uncertain nature | 110201 | |
Leukaemia | 110113 | |
Lung cancer | 110101 | |
Non-Hodgkin's lymphoma | 110112 | |
Oesophageal or Stomach cancer | 110103 | |
Other malignant tumours (including cancer of other respiratory and intrathoracic organs) | 110104, 110199 | |
Skin cancer | 110106 | |
Cardiovascular diseases (5.5%) | Heart failure | 180301 |
Coronary heart diseases (also known as: Ischaemic heart diseases: angina, heart attack and other ischaemic heart diseases) | 180201, 180202, 180299 | |
Other cardiovascular diseases (including other cerebrovascular diseases, oedema and diseases of arteries, arterioles and capillaries) | 180499, 180501, 180601, 189999 | |
Other heart diseases | 180399 | |
Stroke (including after-effects of stroke) | 180401 | |
Chronic respiratory conditions (12%) | Asbestosis | 190107 |
Asthma | 190104 | |
Chronic obstructive pulmonary disease (chronic airflow limitation, chronic bronchitis, emphysema) | 190103, 190105, 190106 | |
Endocrine disorders (5.3%) | Diabetes Type 1 | 130201 |
Diabetes Type 2 | 130202 | |
Diabetes Type unknown | 130203 | |
Gastrointestinal disorders (1.7%) | Diseases of the liver | 200401 |
Diseases of the oesophagus | 200101 | |
Inflammatory bowel disease (enteritis and colitis) | 200601 | |
Genitourinary conditions (2.7%) | Chronic kidney disease (glomerular diseases, renal failure or kidney disease, renal tubulo-interstitial diseases) | 230101, 230102, 230103 |
Non-inflammatory disorders of the female genital tract | 230402 | |
Hearing and vision disorders(a) (21%) | Deafness or hearing loss (complete, partial, deaf mutism and other deafness or hearing loss not elsewhere classified) | 170101 |
Other hearing and vestibular disorders (including, otosclerosis, Meniere’s disease, tinnitus, other diseases of the middle ear and mastoid, other ear and mastoid) | 170299, 170301, 170302, 179901, 179999 | |
Cataracts | 160201 | |
Glaucoma | 160401 | |
Macular degeneration | 160302 | |
Other vision disorders (including complete and partial blindness, colour blindness, retinal disorders or defects, other diseases of the eye and adnexa, other visual disturbances or loss of vision) | 160301, 160601, 160602, 160699, 169901, 169999 | |
Refractive errors (including long sight or hyperopia, short sight or myopia, astigmatism, presbyopia, other disorders of ocular muscles, binocular movement, accommodation and refraction) | 160501, 160502, 160503, 160504, 160599 | |
Infant and congenital conditions (0.8%) | Birth complications (respiratory problems related to birth and other conditions originating in the perinatal period) | 250201, 259999 |
Cerebral palsy | 150801 | |
Congenital brain damage or malformation (including spina bifida) | 260101, 260105 | |
Down syndrome | 260103 | |
Other chromosomal abnormalities | 260104 | |
Other congenital conditions (including deformities of joints or limbs, other congenital malformations and deformations) | 260102, 260199 | |
Infectious diseases (0.1%) | HIV (Human Immunodeficiency Virus), including advanced HIV | 100501 |
Post COVID-19 conditions | 290202 | |
Mental and behavioural conditions (26%) | ADHD | 140601 |
Alcohol | 140201 | |
Anxiety disorders (including feeling anxious nervous or tense, generalised anxiety disorder, obsessive compulsive disorder, panic attack, panic disorder, phobic anxiety disorders, post-traumatic stress disorder and other anxiety related disorders) | 140401, 140402, 140403, 140404, 140405, 140406, 140407, 140499 | |
Autism spectrum disorders | 140501 | |
Bipolar affective disorder (including mania) | 140304, 140305 | |
Conduct disorders | 140602, 140603, 149904 | |
Depression (including feeling depressed and other mood affective disorders) | 140301, 140302, 140399 | |
Harmful use or dependence on drugs (including prescription drugs and other substances) | 140202, 140203 | |
Intellectual impairment | 149903 | |
Other mental health conditions (including dyslexia, dyslalia, speech impairment, other behavioural, other cognitive and emotional problems with usual onset in childhood or adolescence and other mental, behavioural and substance use disorders) | 140102, 140204, 140303, 140502, 140503, 140604, 140699, 149999 | |
Schizophrenia and related conditions (including psychosis) | 149901, 149902 | |
Musculoskeletal conditions (29%) | Osteoarthritis | 220103 |
Rheumatoid arthritis | 220102 | |
Back problems (including sciatica, disc disorders, curvature of the spine and other back pain or problems not elsewhere classified) | 220201 | |
Gout | 220101 | |
Other musculoskeletal and connective tissue conditions (including acquired deformities of joints and limbs, soft tissue disorders, other arthritis and type unknown, other arthropathies, other diseases of the musculoskeletal system) | 220104, 220105, 220199, 220301, 220302, 220303, 220399, 229999 | |
Neurological conditions (8.8%) | Dementia (including frontotemporal dementia, dementia with Lewy bodies, Alzheimer's disease) | 140101, 150401, 150402, 150403 |
Epilepsy | 150601 | |
Migraine | 150602 | |
Motor neurone disease | 150202 | |
Multiple sclerosis | 150501 | |
Other disease of the nervous system (including chronic fatigue syndrome, muscular dystrophy, narcolepsy, Huntington’s disease) | 150201, 150603, 150701, 151001, 159999, 150301 | |
Skin conditions (4.1%) | Dermatitis and eczema | 210201 |
Psoriasis | 210301 |
(a) Vision conditions corrected with glasses are excluded from analysis.
Derived variables used in analysis of NHS data
This report has classified excessive alcohol use based on the 2020 National Health and Medical Research Council Australian guidelines to reduce health risks from drinking alcohol which state: ‘To reduce the risk of harm from alcohol-related disease or injury, healthy men and women should drink no more than 10 standard drinks a week and no more than 4 standard drinks on any one day. The less you drink, the lower your risk of harm from alcohol’.
Individuals were considered to have exceeded the guidelines if they consumed more than 10 drinks in the last week and/or consumed more than 4 drinks on any day at least monthly in the last 12 months (on at least 12 occasions per year).
The NHS variable used to determine whether an individual exceeded the 2020 guidelines was AAAGL20.
Analysis is also provided on the 2 components of the guidelines individually, defined as whether the individual consumed:
- more than 10 drinks in the last week using the variable ALCGL1A
- more than 4 drinks on any day at least monthly in the last 12 months (on at least 12 occasions per year) using the variable ALCGL1B.
Those for whom the question was not applicable, their time since they last consumed alcohol was not known or their risk level was not known were excluded from analysis. Analysis is of people aged 18 and over.
Bodily pain refers to any bodily pain experienced (from any and all causes) in the 4 weeks prior to interview, based on a 6-point scale ranging from ‘none’ to ‘very severe’. Participants were classified as experiencing pain if they indicated their bodily pain was ‘Mild’, ‘Moderate’, ‘Severe’ or ‘Very severe’.
The variable PAINQ01 was used in analysis of people aged 18 and over. Analysis does not include those for whom this measure was not applicable or not stated.
Disability or a restrictive long-term health condition exists if a limitation, restriction, impairment, disease or disorder has lasted, or is expected to last, for 6 months or more, which restricts everyday activities. In the current report, a person was classified as having disability, restriction or limitation if any limitation or restriction was indicated. This included those with either profound, severe, moderate or mild limitation in core activities (mobility, self-care and communication) or restriction in schooling or employment.
Those who indicated that they had no difficulties with school, study or work and had not identified any chronic conditions were identified as having 'no disability, limitation or restriction'.
The variable DISSTAT was used in analysis of people aged 18 and over.
Respondents to the NHS 2022 were asked to provide the number of usual daily serves of fruit and vegetables they consume. This information is captured in the variables: DIETQ5R (usual daily serves of vegetables) and DIETQ8R (usual daily serves of fruit).
These variables were used to calculate a combined measure of adults aged 18 and over who did not usually consume any serves of fruit or any serves of vegetables daily.
Adults aged 18 years and over who responded to the NHS were invited to take part in measured blood pressure readings. For this analysis, people were defined as having measured high blood pressure (hypertension) if their systolic/diastolic blood pressure was equal to or greater than 140/90 mmHg using the variable BPCAT.
In 2022, 39% of respondents did not have their blood pressure measured. For these people, blood pressure was imputed. For more information on imputation, see National Health Survey methodology, 2022.
Body mass index (BMI) is an internationally recognised standard for classifying overweight and obesity in adults. BMI does not necessarily reflect body fat distribution or describe the same degree of fatness in different individuals. However, information to calculate waist-to-height ratio is not collected by the NHS and BMI is considered a practical and useful measure for identifying overweight or obesity at a population level.
BMI is calculated by dividing a person’s weight in kilograms by the square of their height in metres. Measured height and weight information was used to determine overweight and obesity in analysis using the variable BMICATHY. BMI was not measured for 41% of adults who responded to the 2022 NHS. BMI was imputed for those people so that participants with a missing response were given the response of similar participants. For more information on imputation, see National Health Survey methodology, 2022.
In this analysis people were classified as ‘underweight/normal’ (based on a BMI of less than 25) or ‘overweight/obese’ (based on a BMI of 25 or greater), based on the World Health Organization 2000 classification.
Analysis is of people aged 18 and over and does not include those for whom this measure was not applicable or where BMI could not be determined.
The Physical activity and exercise guidelines for all Australians are a set of evidence-based recommendations that outline the minimum amount of physical activity required for health benefits. Australian physical activity and sedentary behaviour guidelines differ across different age cohorts.
In this report, physical activity is examined among people aged 18 and over.
For people aged 18–64, sufficient physical activity is defined as completing 150 minutes of moderate to vigorous activity (where vigorous activity is multiplied by 2) across 5 or more days a week and completing muscle-strengthening activities 2 times a week. Physical activity includes exercise at work, walking for fitness, recreation, or sport; walking to get to or from places; moderate exercise; and vigorous exercise recorded in the week prior to interview. Data does not include people for whom this measure was not known or not applicable.
For people aged 65 and over, sufficient physical activity is defined as being active on most, preferably all days with at least 30 minutes of moderate activity per day. This is interpreted in this analysis as at least 5 days of physical activity for at least 30 minutes, including workplace activity.
Remoteness is classified according to the Australian Statistical Geography Standard (ASGS) 2021 Remoteness Areas structure based on area of residence. Remoteness Areas divide Australia into 5 classes of remoteness based on a measure of relative access to services. The 5 remoteness areas are Major cities, Inner regional, Outer regional, Remote and Very remote. For more information, see ABS Remoteness structure.
Very remote areas are not included in this analysis, as these areas are outside of the scope of the NHS. For more information, see ‘Scope of the survey’ in the ABS National Health Survey: First results methodology, 2022.
Due to small numbers and the need to protect privacy, Remote Australia has been combined with Outer Regional Australia for results presented by remoteness area.
Self-assessed health status reflects a person's subjective perception of his or her own health at the time of interview. In the 2022 NHS, survey participants were asked “In general would you say that your health is excellent, very good, good, fair or poor?”
Analysis uses the variable SAHQ01. Those who rated their health as ‘fair’ or ‘poor’ were grouped, and those who rated their health as ‘excellent’, ‘very good’ or ‘good’ were also grouped.
The 2022 NHS uses the Standard for Sex, Gender, Variations of Sex Characteristics and Sexual Orientation Variables, 2020. Data in this publication are presented using the Sex at birth variable. Due to small numbers and the need to protect privacy, people who reported sex at birth as a term other than male or female are not reported separately or included in the total Persons category.
Socioeconomic areas are classified according to the Socio-Economic Indexes for Areas (SEIFA) 2021 Index of Relative Socio-Economic Disadvantage (IRSD).
The IRSD classifies individuals according to the socioeconomic characteristics of the area in which they live. It scores each area by summarising attributes of the population, such as low income, low educational attainment, high unemployment and jobs in relatively unskilled occupations. Areas can then be ranked according to their score. In this analysis, the population living in the 20% of areas with the greatest overall level of disadvantage is described as living in the ‘lowest socioeconomic areas’. The 20% of areas with the lowest level of disadvantage – the top fifth – is described as the ‘highest socioeconomic areas’.
Note that the IRSD reflects the overall or average level of disadvantage of the population of an area; it does not show how individuals living in the same area differ from each other in their socioeconomic position. For more information, see the ABS Socio-economic indexes for areas (SEIFA):Technical paper 2021.
Current daily smoking is used as a proxy for tobacco use in analysis.
Participants in the 2022 NHS were asked whether they currently smoked at least once per day. A person who currently smokes daily was defined as a person who smokes one or more cigarettes, roll-your-own cigarettes, cigars or pipes at least once a day. People who used chewing tobacco, electronic cigarettes (and similar) or smoked non-tobacco products were not counted in this definition unless they also smoked daily. People who smoked less than daily or who previously smoked daily are also not counted in this definition.
The NHS variable used to determine daily smoking was SMOKSTAT. Analysis includes people aged 18 and over.
People were classified as either in the labour force (workforce) or not in the labour force using the variable LFS based the following criteria:
- In the labour force includes two groups:
- those working – these are employed people who reported that in the preceding week they had worked in a job, business or farm, or who had a job but were absent during that week.
- those seeking work – people who were not employed but actively looking for work in the four weeks prior to the survey and were available to start work in the week prior to the survey.
- Not in the labour force: those who were not employed or seeking work, including those who were studying, not currently working, retired, are permanently unable to work, or have never worked and never intend to work.
Labour force participation was examined among people aged 18 to 64 years.
Estimating prevalence and statistical significance
Crude and age standardised estimates
Unadjusted (crude) weighted prevalence estimates provide important information on the actual level of multimorbidity in the population under study. Crude proportions are reported unless otherwise stated.
Statistically significant differences in age-specific proportions are determined by comparing the crude proportions and their standard errors.
Age-standardisation is used to remove the influence of age when comparing populations with different age structures. Age-standardised proportions are used to inform whether comparisons between population groups (such as men and women of all ages) are statistically significantly different.
The age-standardised proportions in this report have been directly age-standardised to the 2001 Australian standard population. For age-standardised estimates, see Data tables.
Relative standard error, margin of error and confidence intervals
The relative standard error (RSE) of an estimate is a measure of the error likely to have occurred due to sampling. The RSEs of the estimates were calculated using the standard errors (SEs):
RSE% = (SE/estimate) * 100
The margin of error (MoE) at the 95% confidence level for each estimate was calculated using 1.96 as the critical value:
MoE = 1.96 * SE
The MoE was then used to calculate the 95% confidence interval (CI) around each estimate:
95% Confidence Interval = estimate ± MoE
The 95% CI is a range of values determined by the variability in data, within which there is a 95% chance that the confidence interval will contain the true value of the population quantity being estimated.