PREVMED Pearlets Flashcards
Group of subjects who are followed forward in time to see which ones develop the outcome
COHORT
Prospective studies in which an intervention is applied
CLINICAL TRIALS
Similar in design to a prospective cohort study but both the exposure and outcome have occured when the study is undertaken
RETROSPECTIVE COHORT STUDY
Average or sum of the observations divided by the number of observations
MEAN
Middle observation in a series of ordered observations
MEDIAN
Observation that occurs with greatest frequency
MODE
Used for categorical data if no cell has an expected count less than 1 and no more than 20% of the cells have an expected count of less than 5
CHI-SQUARE
Used when 50% of cells have an expected count less than 5
FISER’S EXACT TEST
Used for independent continuous data
STUDENT t TEST
Used for analysis of several independent means
ANALYSIS OF VARIANCE
How are incidence rate measure
Number of new cases per total population x time = cases per person-years
Ratio of incidence of a disease in a group exposed to a factor
RELATIVE RISK
Investigators determine exposure of the study and control groups to a suspected causal factor and measures response in the 2 groups
EXPERIMENTAL STUDIES
Type of study wherein investigators have no control over exposure to a suspected causal factor but can measure responses in those who are and are not exposed
OBSERVATIONAL STUDIES
Systematic errors in the way subjects are included in the study
SELECTION BIAS
Occurs when the apparent effect of an exposure is partly or entirely due to a third factor associated with both exposure and outcome
CONFOUNDING
Well suited to studying rare disorders with multiple potential causes
CASE CONTROL STUDIES
Window period between the time the cancer can be detected when it is asymptomatic by a screening test and the time it will become clinically apparent is short
LENGTH BIAS
Occurs when the screening test advances the time of diagnosis
LEAD-TIME BIAS
Systematic difference in the way data are collected for either the exposure or the outcome
INFORMATION BIAS
