51 notecards = 13 pages (4 cards per page)
Any quantity that varies. Any attribute phenomenon or event that can have different variables.
Can have an infinite number of values within a specified range.
As one value increases, the other values increases.
As one value increases, the other value decreases.
outcome or effect
X is not related to Y
X does not cause Y
X causes Y
The plot of a dose-response relationship, which is a type of correlative association between an exposure and an effect.
The lowest dose at which a particular response occurs.
Has several peaks in the frequency of a condition.
The time period between initial exposure and a measurable response.
A graphic plotting of the distribution of cases by time of onset.
A type of table that tabulates data according to two dimensions.
Method of Difference
All of the factors in two or more domains are the same except for a single factor, which is hypothesized to be the “cause” of a disease.
Method of Concomitant Variation
The method in which a quantitative change in the effect is associated with quantitative changes in a given factor.
the process of defining measurement procedures for the variables used in a study
a single value (sample-based) chosen to represent the population parameter
Investigator does not have control over the exposure factor and usually is unable to assign subjects randomly to study conditions
Investigator controls who is exposed to a factor of interest and assigns subjects randomly to study groups
a study in which the units of analysis are populations or groups of people rather than individuals
Ecologic comparison study
involves an assessment of the association between exposure rates and disease rates during the same time period
an association between two variables (exposure and outcome) measured at the group level
Subjects are defined on the basis of the presence or absence of an outcome of interest.
Cases are those individuals who have the outcome or disease of interest, whereas the controls do not.
Matched case-control study
the cases and controls have been matched according to one or more criteria such as sex, age, race, or other variables
A measure of the association between frequency of exposure and frequency of outcome used in case-control studies.
A population group, or subset thereof (distinguished by a common characteristic), that is followed over a period of time.
Prospective Cohort Study
Subjects are classified according to their exposure to a factor of interest and then are observed over time to document the occurrence of new cases (incidence) of disease or other health events.
Retrospective Cohort Study
Makes use of historical data to determine exposure level at some
baseline in the past
Historical Prospective Cohort Study
Combines retrospective and prospective approaches
The ratio of the incidence rate of a disease or health outcome in an exposed group to the incidence rate of the disease or condition in a non-exposed group.
Incidence rate in the exposed/
The difference between the incidence rate of a disease in the exposed group and the incidence rate in the non-exposed group.
Population Risk Difference
incidence in the total population − incidence in the non-exposed segment
An investigation involving intentional change in some aspect of the status of the subjects
Randomized controlled trial
subjects in a population are randomly allocated into groups, usually called study and control groups, to receive or not to receive an experimental preventive or therapeutic procedure, maneuver, or intervention
designed to test preventive measures
A research activity that involves the administration of a test regimen to humans to evaluate its efficacy and safety
participants may be switched between treatment groups
an intervention designed for the purpose of educational and behavioral changes at the population level
a type of research in which the investigator manipulates the study factor but does not assign individual subjects randomly to the exposed and non-exposed groups
Used to determine whether the program meets stated goals and is justified economically
A type of error that arises when values (statistics) obtained for a sample differ from the values (parameters) of the parent population
Refers to the degree to which the study has used methodologically sound procedures
Systematic deviation of results or inferences from truth
Participants’ behavioral changes as a result of their knowledge of being in a study
Cases may remember an exposure more clearly than controls.
Distortions that result from procedures used to select subjects and from factors that influence participation in the study
Healthy worker effect
The “observation that employed populations tend to have a lower mortality experience than the general population.”
The distortion of a measure of the effect of an exposure on an outcome due to the association of the exposure with other factors that influence the occurrence of the outcome.