randomized control trial
An experiment in which subjects in a population are randomly allocated to groups (usually treatment and control groups) and either receive or don't receive an experimental preventative or therapeutic procedure, manoeuvre or intervention.
randomization
The random assignment of subjects to either the treatment or non-treatment group.
stratified randomization
The separation of a sample into several sub-samples according to specified criteria.
placebo
An inert medication or procedure that is intended to make subjects feel as though they are receiving treatment.
single blind
Blinding the patient to the treatment being received.
research ethics board
Responsible for reviewing all research applications according to the relevant legal and ethical regulations.
inferential statistics
Blinding the patient and the investigator to the treatment being received.
incidence rates
The rate at which new events or cases of disease occur in a population.
prevalence
The number of events or instances of disease or condition in a given population at a specified time.
ratio
The value obtained by dividing one quantity by another; a general term in which rate, proportion and percentage are subsets.
experimental studies
A study in which conditions are under the control of the researcher, ie., randomized control trial.
proportion
A type of ratio in which the numerator is included in the denominator and therefore the value is dimensionless.
independent variable
The characteristic being observed or measured that is hypothesized to influence another event (the dependent variable) within a study.
dependent variable
A variable, the value of which is dependent on the effect of other variables in the relationship under study.
confounding variable
Variable that can cause or prevent the outcome being studied and is associated with the factor under study.
bias
Deviation of results from the truth or processes that lead to such deviations; within a research study, procedures are followed to attempt to reduce the introduction of bias into the study design.
retrospective cohort study
Research design used to test hypotheses about etiology in which inflate des about exposure to the hypothesized casual factors are derived from data relating to characteristics of the persons under the study or to events or experiences in the past.
prospective cohort study
A study that follows subjects forward in time.
cohort study
An epidemiological study in which subsets of a defined population can be identified who are or have been (retrospective study) or who may be, in the future (prospective study), exposed to a factor that is thought to influence the occurrence of a given dis
contingency table
A tabular cross-classification of data such that subcategories of one characteristics are indicated horizontally in rows and subcategories of another classification are indicated vertically in columns.
correlational (ecological) study
Uses data from entire populations to compare disease frequencies between different groups during the same period of time or within the same populations at different points in time.
cross-sectional (prevalence) studies
Examines the relationship between diseases (or other health-related outcome or characteristic) and other variables of interest as they exist in a defined population at one particular time.
focus group
A small convenience sample of a group brought together to discuss a topic or issue to ascertain and record the range of views.
observational study
A study in which the researcher simply observes or records the changes in one characteristic being studied in relation to changes in other characteristics.
quantitative research
A research methodology that uses numerical measures to explore group characteristics or behaviour.
qualitative research
A research methodology that employs non-numeric information to explore individual or group characteristics.
mixed methods
A combination of qualitative and quantitative research methods.
epidemiology
The health science that deals with the distribution and incidence of diseases in human populations.
agent
In the epidemiological sense refers to any living or non-living sources which act to produce disease within a host.
endemic
In referring to a disease, that is present within a given population at a relatively constant rate and demonstrates little variance in it's prevalence.
epidemic
In referring to a disease, an outbreak or spread of disease that is observed at a higher than normal frequency or rate affecting a larger subset of a given population than would normally be expected.
pandemic
A pandemic is defined as an epidemic that occurs on a much larger scale, usually affecting multiple countries or continents and a far greater number of individuals.
reliability
The degree to which the results obtained by a measurement or procedure can be replicated.
validity
The degree to which a measurement actually measures what it purports to measure.
variables
Any attribute, phenomenon or event that have different values; any quantity that varies.
sample
A selected subset of a population. In a random sample, all individuals have an equal chance of selection and are selected at random from a random number table until the desired sample size is obtained.
null hypothesis
Statistically, an assumption about population distribution and population mean that is tested against alternative hypotheses.
peer review
Process of review of research proposals/grants, manuscripts for publication, conference abstracts for scientific and technical merit by other researchers/scientists in the same field.
triple blind
Blinding the patient, investigator and analyst to the treatment.
statistical validity
Concerned with the notion that the statistical tests used on the data are appropriate and accurate.
construct validity
Answers the questions as to whether the theory presented as a result of the data is the best explanation for the observations in the data or evidence.
internal validity
Concerned with the question of whether or not the independent variable is responsible for the observed changes in the dependent variable(s) within the data.
external validity
Addresses the question of whether the results apply to a broader population or situation.
primary study
Study in which new data must be collected to answer the research question.
secondary study
Study in which pre-existing data is employed to answer the research question.
tertiary study
Study where the data findings from other previously completed studies are used.
autonomy
Respect for persons means that the participant in the study understands the nature of the study and has agreed to participate.
beneficence
The concept that the research is meant to build on the body of knowledge that exists with regard to the subject matter being researched and the outcomes of the research will be of benefit to the participants.
justice
The benefits and burdens of the research are shared by all involved in the study.
clinical trial
Alternate term for a randomized controlled trial.
content analysis
The examination of qualitative data collected as part of a research study.