Technical glossary

Age-specific death rate Number of deaths of persons of a specific age group in one year per 1,000 persons of the same age group.
Age-specific fertility rate The number of livebirths to women in a specified age group in one year per 1,000 women in the same age group.
Age-standardisation A procedure for adjusting rates (such as population death rates) to minimise the effects of differences in age composition and thus facilitate valid comparison of rates for populations with different age compositions. See direct standardisation and indirect standardisation.
Body mass index (BMI) Is calculated by dividing weight in kilograms by height in metres squared, and categorises a person as ranging from underweight to obese: underweight (BMI: <18.5); normal (BMI: 18.5-24.9); overweight (BMI:25.0-29.9); obese (BMI:30.0+)
Confidence interval (CI) Range determined by variability in data, within which there is a specified chance that a calculated parameter is thought to lie.
Direct standardisation The procedure for adjusting rates in which the specific rates for a study population are averaged using as weights the distribution of a standard population.
Epidemiology The study of the distribution and determinants of health-related states and events in populations, and the application of this study to control of health problems.
Excess deaths The difference between the actual number of deaths occurring and the number expected from rates for the comparable population (the population used for comparison may vary, but is most often the total Australian population or the total for the specific jurisdictions being considered)
Expectation of life Predicted number of years of life remaining to a person if the present pattern of mortality does not change. It is a statistical abstraction based on current age-specific death rates.
Fertility rate See age-specific fertility rate.
Incidence The number of instances of illness commencing, or of persons falling ill, during a given period in a specified population (see incidence rate and cumulative incidence).
Incidence rate (or incidence density) The number of instances of illness commencing, or of persons falling ill, during a given period in a specified population divided by the population at risk
Indirect standardisation The procedure for adjusting rates in which the specific rates in a standard population are averaged using as weights the distribution of the study population.
Infant mortality rate Number of infant deaths per 1,000 live births
International Classification of Disease (ICD) WHO's internationally accepted classification of death and disease - the ninth revision (ICD-9) is currently in use (WHO 1977).
Life expectancy See expectation of life.
Maternal death The death of a woman while pregnant or within 42 days of the termination of pregnancy, regardless of the duration and site of the pregnancy, from any cause related to or aggravated by the pregnancy or its management. Direct maternal deaths, a subset of all maternal deaths, are those resulting from obstetric complications of the pregnant state (pregnancy, labour and puerperium), from interventions, omissions, incorrect treatment, or a chain of events resulting from any of the above. They are complications of the pregnancy itself.
Maternal mortality ratio Number of maternal deaths divided by the number of confinements (in 100,000s)
Median age at death The age above and below which 50% of deaths occurred
Morbidity Any departure, subjective or objective, from a state of physiological or psychological wellbeing.
Mortality Death.
Odds ratio The ratio of two odds; the estimate of the ratio of the risk of disease or death among the exposed to the risk among the unexposed, when it is not possible to estimate the incidences of disease for the two groups (such as in a case-control study).
Population A large group of individuals; all the possible units from which a sample may be drawn.
Prevalence The number of instances of a given disease or other condition in a given population at a designated time.
Public health One of the efforts organised by society to protect, promote, and restore the people's health. It is the combination of sciences, skills, and beliefs that are directed to the maintenance and improvement of the health of all the people through collective or social actions. The programs, services, and institutions involved emphasise the prevention of disease and the health needs of the population as a whole. Public health activities change with changing technology and social values, but the goals remain the same: to reduce the amount of disease, premature death, and disease-produced discomfort and disability in the population. Public health is thus a social institution, a discipline, and a practice.
Rate ratio The ratio of two rates - used to indicate the relative rates between two populations of a particular disease or condition.
Relative risk The ratio of the risk of disease or death among the exposed to the risk among the unexposed.
Risk factor An attribute or exposure that is associated with an increased probability of a specified outcome, such as the occurrence of a disease. Not necessarily a causal factor.
Risk The probability that an event will occur.
Sample A sub-group selected from the population for convenience and from which inferences are made about the population.
Standardisation The process by which adjustments are made to take account of differences in the age structures of populations.
Standardised mortality ratio (SMR) The ratio of the observed number of deaths in a study population to the number expected if the study population had the same age-specific rates as a standard population. (The SMR is expressed sometimes as the ratio multiplied by 100.). See age-standardisation and indirect standardisation.
Total fertility rate The number of livebirths a woman would have if, throughout her reproductive years, she had children at the rates prevailing in the reference calendar year. It is the sum of the age-specific fertility rates for that calendar year.
WHO World Health Organization.

References

1. Concise medical dictionary (1980) Oxford University Press, Oxford
2. Dorland's Illustrated Medical Dictionary (1985) 26th edition, WB Saunders, Philadelphia
3. Last, J.M. (ed.) (1995) A dictionary of epidemiology. Third edition. Oxford University Press, New York
4. Greenberg, R.S., Daniels, S.R., Flanders, W.D., Eley, J.W., & Boring, J.R. (1996) Medical epidemiology. Second edition.London: Prentice-Hall International Inc.
5. World Health Organization (1977) Manual of the international statistical classification of diseases, injuries and causes of death. Ninth revision, volumes 1 and 2. WHO, Geneva

Last updated: 20 December 2005