Aboriginal or Torres Strait Islander: A person of Aboriginal and/or Torres Strait Islander descent who identifies as an Aboriginal and/or Torres Strait Islander. See also Indigenous.

additional diagnosis: The diagnosis of a condition or recording of a complaint—either coexisting with the principal diagnosis or arising during an episode of admitted patient care (hospitalisation)—that requires the provision of care. Multiple diagnoses may be recorded.

ADF members (previously ADF personnel): permanent, reserve and ex-serving members of the Australian Defence Force (ADF); does not include civilian personnel employed by the Department of Defence.

administrative data collection: A data set that results from the information collected for the purposes of delivering a service or paying the provider of the service. This type of collection is usually complete (all in-scope events are collected), but it may have limitations for population-level analysis because the data are collected primarily for an administrative purpose.

admission: An admission to hospital. The term hospitalisation is used to describe an episode of hospital care that starts with the formal admission process and ends with the formal separation process.

aged care services: Regulated care delivered in either residential or community settings, including the person’s own home. Most formal care is funded through government programs but may also be purchased privately. The Department of Veterans’ Affairs funds care programs for eligible veterans, war widows and widowers.

age-specific rate: The number of events for a specified age group over a specified period (e.g. calendar or financial year), divided by the total population in that age group. Reported as number per 100,000. The numerator and denominator relate to the same age group.

age-standardisation: A method of removing the influence of age when comparing populations with different age structures. This is usually necessary because the rates of many events (e.g., deaths, service use) vary with age. The age structures of the different populations are converted to the same ‘standard’ structure, and then the rates that would have occurred with that structure are calculated and compared.

age structure: The relative number of people in each age group in a population.

alcohol use disorder: A class of mental disorder involving the harmful use and/or dependence on alcohol.

all-cause mortality: Deaths due to any cause.

Associated cause(s) of death: Any condition(s), diseases and injuries—other than the underlying cause of death—considered to contribute to a death.

Australia’s Physical Activity and Sedentary Behaviour Guidelines: The guidelines recommend that adult Australians aged 18–64:

  • be active on most, preferably all, days every week
  • accumulate 150 to 300 minutes of moderate intensity physical activity or 75 to 150 minutes of vigorous intensity physical activity, or an equivalent combination of both moderate and vigorous activities, each week
  • do muscle-strengthening activities on at least 2 days each week
  • minimise the amount of time spent in prolonged sitting
  • break up long periods of sitting as often as possible.

For Australians aged 65 and over, the guidelines recommend people should be active every day in as many ways as possible and accumulate at least 30 minutes of moderate intensity physical activity on most, preferably all, days.

body mass index (BMI): The most commonly used method of assessing whether a person is normal weight, underweight, overweight or obese, which is calculated by dividing the person’s weight (in kilograms) by their height (in metres) squared; that is, kg ÷ m2. For both men and women, underweight is a BMI below 18.5, acceptable weight is from 18.5 to less than 25, overweight is from 25 to less than 30, and obese is 30 and over. Sometimes overweight and obese are combined and defined as a BMI of 25 and over. At the time of the 2017–18 NHS interview, respondents had their height and weight measured and subsequently BMI was calculated.

cancer (malignant neoplasm): A large range of diseases where some of the body’s cells become defective, begin to multiply out of control, invade and damage the area around them, and can then spread to other parts of the body to cause further damage.

cardiovascular disease/condition: Any disease of the circulatory system, namely the heart (cardio) or blood vessels (vascular). Includes angina, heart attack, stroke, and peripheral vascular disease. Also known as circulatory disease.

Cause(s) of death: All diseases, morbid conditions or injuries that either resulted in or contributed to death—and the circumstances of the accident or violence that produced any such injuries—that are entered on the Medical Certificate of Cause of Death. Causes of death are commonly reported by the underlying cause of death.

certified suicide death: Official fact of death and cause of death determination (including suicide death) from the Registrars of Births, Deaths and Marriages in each state and territory and the National Coronial Information System, compiled and coded by the Australian Bureau of Statistics.

chronic diseases/conditions: A diverse group of diseases/conditions, such as heart disease, cancer and arthritis, which tend to be long lasting and persistent in their symptoms or development. Although these features also apply to some communicable diseases (infectious diseases), the term is usually confined to non-communicable diseases. Examples of chronic diseases include diabetes, asthma and heart disease.

cohort: A group of people who share a similar characteristic(s) (for example, age).

combat death: A death that occurs during an action fought between two military forces.

commissioned officer: An appointed Defence member who holds a rank of Midshipman or Officer Cadet, or higher.

confidence interval: A range determined by variability in data, within which there is a specified (usually 95%) chance that the true value of a calculated parameter lies.

core activity limitation: A limitation where one needs assistance with, has difficulties with, or uses aids or equipment to help with self-care, mobility and/or communication.

correlation: The strength of an association between variables, given by a value between –1 and 1, where stronger relationships are indicated by values further away from 0. High correlation can be defined as being greater than 0.70 or less than –0.70.

counts of death: The number of deaths in a population in a given time period.

COVID-19: A disease of the respiratory system, particularly in the early stages of the illness, caused by the coronavirus SARS-CoV-2. Common early symptoms are similar to other respiratory illnesses, but the infection can have a wide variety of manifestations. In some people the infection can progress to become a more severe disease, with the immune system overreacting, resulting in inflammation and lack of oxygen to many parts of the body. This can lead to multiple organ failure and death. Severe symptoms tend to develop in the second week of the disease.

crude rate: The number of occurrences of an event (for example, number of deaths) divided by the corresponding population multiplied by 100,000 (which provides the number of events (deaths) per 100,000 population in a given time period).

current smoker: A person who reported at the time of interview that they smoked cigarettes, cigars or pipes.

data linkage: The bringing together (linking) of information from two or more different data sources that are believed to relate to the same entity; for example, the same individual or the same institution. This linkage can yield more information about the entity and in certain cases, provide a time sequence—helping to ‘tell a story’, show ‘pathways’ and perhaps unravel cause and effect. The term is used synonymously with ‘record linkage’ and ‘data integration’.

demographic characteristics: Characteristics of a population expressed statistically, such as age and sex.

dependant: The partner, parent, step-parent, grandparent, child, step-child, grandchild, sibling or half-sibling of a permanent or former ADF member. The member’s partner’s parent, step-parent, child or step-child may also be included as dependants. Further, a dependant may also include a person who stands in the position of a parent to the member, or a person in respect of whom the member stands in the position of a parent.

deployment: See operational service.

disability: An umbrella term for any or all of an impairment of body structure or function, a limitation in activities, or a restriction in participation. Disability is a multidimensional concept and is considered as an interaction between health conditions and personal and environmental factors.

discharge (ADF):  Separation from the ADF.

employed: Describes people aged 15 and over who have a job or business, or who undertake work without pay in a family business for a minimum of 1 hour per week. Includes people who are absent from a job or business.

ex-serving: Australian Defence Force members who have separated from the serving or reserve population.

ex-smoker: A person who reported that they did not currently smoke, but previously either:

  • regularly smoked daily
  • had smoked at least 100 cigarettes
  • smoked pipes, cigars, etc at least 20 times in their lifetime.

external cause of death (or injury-related death): Is one of a group of causes external to the body (for example, suicide, transport accidents, falls, poisonings and assault).

family: Two or more people, one of whom is at least 15 years old, who are related by blood, marriage (registered or de facto), adoption, step or fostering, and who are usually living in the same household. Each separately identified couple relationship, lone parent to child relationship or other blood relationship forms the basis of a family. Some households contain more than one family.

general practitioner (GP): A medical practitioner who provides primary comprehensive and continuing care to patients and their families within the community.

hospitalisation: The term used to refer a completed episode of admitted hospital care ending with discharge, death, transfer or a portion of a hospital stay beginning or ending in a change to another type of care (for example, from acute care to rehabilitation). The hospital separations data do not include episodes of non-admitted patient care provided in outpatient clinics or emergency departments. Patients in these settings may be admitted subsequently, with the care provided to them as admitted patients being included in the NHMD.

incidence: The number of new cases (of an illness or event, and so on) occurring during a given period. Compare with prevalence.

incidence relative risk (cancer): The ratio of the observed cancer incidence rate in the study population to the estimated (weighted) rate in the comparison population(s).

Indigenous: A person of Aboriginal and/or Torres Strait Islander descent who identifies as an Aboriginal and/or Torres Strait Islander.

informal carer: A person of any age who provides any informal assistance, in terms of help or supervision, to people with disability or long-term conditions, or to people aged 65 and over. This assistance must be ongoing, or likely to be ongoing, for at least 6 months.

labour force: People who were employed or unemployed (that is, not employed but actively looking for work).

leading cause of death: The underlying cause of death categories (ICD-10) or groupings (such as coronary heart disease, land transport accidents) that account for the largest numbers of deaths within a population or age group.

length of service: The time between the date of hire and date of separation (discharge) from the ADF.

length of stay (hospital): Duration of hospital stay, calculated by subtracting the date the patient is admitted from the date of separation. All leave days, including the day the patient went on leave, are excluded. A same-day patient is allocated a length of stay of 1 day.

lifetime risk (alcohol): The accumulated risk from drinking either on many drinking occasions, or on a regular (for example, daily) basis over a lifetime. The lifetime risk of harm from alcohol-related disease or injury increases with the amount consumed. For healthy men and women, drinking no more than 2 standard drinks on any day reduces the lifetime risk of harm from alcohol-related disease or injury.

long-term condition: A term used to describe a health condition that has lasted, or is expected to last, at least 6 months.

median: The midpoint of a list of observations that have been ranked from smallest to largest.

median age: The age at which half the population is older than that age and half is younger than that age.

Medicare: A national, government-funded scheme that subsidises the cost of personal medical services for all Australians and aims to help them afford medical care. The Medicare Benefits Schedule (MBS) is the listing of the Medicare services subsidised by the Australian Government. The schedule is part of the wider Medicare Benefits Scheme (Medicare).

mortality: Number or rate of deaths in a population during a given time period.

mortality relative risk: The ratio of the observed mortality rate in the study population to the estimated (weighted) rate in the comparison population(s).

never smoked: A person who reported that they had:

  • never regularly smoked daily; and
  • smoked less than 100 cigarettes in their lifetime; and
  • smoked pipes, cigars, etc less than 20 times in their lifetime.

non-school qualification: Educational attainments other than those of pre-primary, primary and secondary education. They include qualifications at the following levels: Postgraduate Degree, Graduate Diploma and Graduate Certificate, Bachelor Degree, Advanced Diploma and Diploma, and Certificates I, II, III and IV. Non-school qualifications may be attained concurrently with school qualifications.

nutrition: The intake of food, considered in relation to the body’s dietary needs.

odds ratio: A measure of the association between an exposure and an outcome. The odds ratio represents the odds that an outcome will occur, given a particular exposure, compared with the odds of the outcome’s occurring in the absence of that exposure. For example, if the odds ratio between all ranks other than commissioned officers and commissioned officers is 2.2, this means that the particular outcome (such as death due to suicide) has 2.2 times the odds for all ranks other than commissioned officers than for commissioned officers, if all other factors (such as service) are held constant.

operational service: The four broad categories of ADF deployment or operations:

  • warlike operational service—warlike/active service deployments
  • non-warlike operational service—non-warlike deployments (for example, peace keeping, peace monitoring, United Nations assistance missions)
  • overseas operational service—humanitarian/disaster relief (International) or border protection deployments
  • domestic operational service—deployment of Defence aid to the civilian community.

Individuals with at least one type of operational service are classified as having ‘operational experience’, and those with no operational service are counted in ‘no operational experience’.

p-value: The probability that an observed difference has arisen by chance alone.

peacetime service: Service provided by an Australian person who is serving, or has served, with a Peacekeeping Force outside Australia. These are military operations in support of diplomatic efforts to restore peace between belligerents, who may not be consenting to intervention and may be engaged in combat activities.

permanent force: Members of the permanent forces of the ADF—Permanent Navy, Regular Army and Permanent Air Force—who usually serve in a full-time capacity and commit to an initial minimum period of service commensurate with the job role, rank and level of training.

Pharmaceutical Benefits Scheme (PBS): A national, government-funded scheme that subsidises the cost of a wide range of pharmaceutical drugs for all Australians to ensure timely, reliable and affordable access to necessary medicines. The Schedule of Pharmaceutical Benefits (Schedule) is published monthly and lists all the medicinal products available under the PBS and explains the uses for which they can be subsidised.

prevalence:  The number or proportion (of cases, instances, and so forth) in a population at a given time. In relation to cancer, refers to the number of people alive who had been diagnosed with cancer in a prescribed period (usually 1, 5, 10 or 26 years). Compare with incidence.

principal diagnosis: The diagnosis established after study to be chiefly responsible for occasioning an episode of patient care (hospitalisation), an episode of residential care or an attendance at the health care establishment.

protective factors: Factors that enhance the likelihood of positive outcomes and lessen the chance of negative consequences from exposure to risk.

rank: One’s position in the ADF operational hierarchy. Analysis by rank is often presented for two broad groups: commissioned officer, and all ranks (Sailor, Other Ranks or Airman/Airwoman Rank) other than commissioned officer.

rate: One number (the numerator) divided by another number (the denominator). The numerator is commonly the number of events in a specified time. The denominator is the population “at risk” of the event. Rates (crude ratesage-specific rates and age-standardised – see age-standardisation) are generally multiplied by a number such as 100,000 to create whole numbers.

reason for separation: The main reason recorded for a person’s separation (discharge) from the ADF, that is, when a member is no longer permanent or reserve. Analysis by reason for separation from the ADF can be categorised into four broad groups:

  • voluntary separation—comprising personnel who take voluntary redundancies or who resign
  • involuntary medical separation—comprising personnel deemed unsuitable for medical reasons.
  • contractual/administrative change—includes contract completed and data migration requirement in Defence personnel system.
  • other involuntary separation—includes being physically unfit for service, training failure and disciplinary reasons.

relative risk:  This measure is derived by comparing two groups for their likelihood of an event. It is also called the risk ratio because it is the ratio of the risk in the ‘exposed’ divided by the risk in the ‘unexposed’. It is also known as the rate ratio.

Repatriation Pharmaceutical Benefits Scheme (RPBS):  The RPBS is subsidised by the Department of Veterans’ Affairs (DVA), and can be accessed by veterans who have the following DVA cards:

  • Gold or Orange Card (all medical conditions)
  • White Card (specific medical conditions).
  • Under the RPBS, eligible veterans/war widow(er)s may receive:
  • items listed for supply in the PBS
  • items listed under the RPBS, including wound care products
  • items not listed on either the PBS or RPBS schedules, if clinically justified.
  • All medicines supplied under the RPBS are dispensed at the concessional rate (or free if the patient has reached their Safety Net threshold).

reserve/reservist: ADF members in the active or inactive reserve forces for the Navy, Army or Air Force. Most members leaving full-time service make the transition to the inactive reserve forces unless there are medical or other grounds preventing this.

risk: The probability of an event occurring during a specified period of time.

separations: can be either same-day (where the patient is admitted and separated on the same day) or overnight (where the patient is admitted to hospital and separates on a different date).

service: The three broad arms of the ADF—the Navy, Army and Air Force.

service status: The broad nature of an individual’s employment with the ADF, namely: permanent (previously referred to as serving), reserve and ex-serving.

specialist homelessness agency client: a person who receives a specialist homelessness service. A client can be of any age. Children are also clients if they receive a service from a specialist homelessness agency. To be a client the person must directly receive a service and not just be a beneficiary of a service. Children who present with an adult and receive a service are considered to be a client. Children of a client or other household members who present but do not directly receive a service are not considered to be clients.

standard drink (alcohol): Containing 10 grams of alcohol (equivalent to 12.5 millilitres of alcohol). Also referred to as a full serve.

standardised incidence ratio: The ratio of the incidence rate of a disease or condition in the study population or comparison population(s) to the rate in the Australian population, adjusting for differences in age structure between the two populations.

standardised mortality ratio (SMR): A ratio to compare mortality rates for the three Australia Defence Force (ADF) service status groups with the Australian population, adjusting for differences in age structure.

statistical power: The likelihood that a study will detect a true difference, where one exists.

statistical significance: A statistical measure indicating how likely the observed difference is due to chance alone.

suicide: An action intended to deliberately end one’s own life.

time since separation (discharge): The period between separation (discharge) from the ADF and death for ex-serving members who have died. The period between separation date and extract date (depending on extract) for those alive at the extract date. No abbreviation used e.g. TSS.

transition: The process of moving from full-time, part-time or reserve ADF service into civilian life.

underlying cause of death: The disease or injury that initiated the train of events leading directly to death; that is, the primary or main cause of death. The underlying cause of death as reported on the National Mortality Database is used to assign the cause of death.

weighting: Adjustment of the characteristics of one group so they are statistically similar to the characteristics of another group so that comparisons of the effect under study can be more certain.