EPID 4070: Test 2

Ecologic study
Study where the unit of analysis is the group, not the individual; can be used for generating hypotheses; level of exposure for each individual in the unit studied is unknown
Ecologic comparison study
involves an assessment of the correlation between exposure rates and disease rates among different groups over the same time period
Ecologic trend study
involves correlation of changes in exposure with changes in disease within the same community, country, or other aggregate unit
Ecologic fallacy
observations made at the group level may not represent the exposure-disease relationship at the individual level
Ecologic fallacy
occurs when incorrect inferences about the individual are made form group level data
Cross-sectional study
study during a single period of observation where exposure and disease histories are collected simultaneously; exposure and disease measures obtained at the individual level
Case-Control Studies
study in which one group has the disease of interest, and a comparable group is free from the disease
Case-Control Studies
study that identifies possible causes of disease by finding out how two groups (one control and one case) differ with respect to exposure to some factor
Temporality
refers to the timing of information about cause and effect
Cohort
a population group, or subset thereof, that is followed a period of time
Cohort
study in which members experience a common exposure associated with a specific setting or they share a non-specific exposure associated with a general classification
Wade Hampton Frost
popularized cohort analysis method–arranged tuberculosis mortality rates in a table with age on one axis and year of death on the other
life table method
gives estimates for survival during time intervals and present the cumulative survival probability at the end of the interval
cohort life table
shows the mortality experience of all persons born during a particular year
Period life table
enables us to project the future life expectancy of persons born during the year as well as the remaining life expectancy of persons who have attained a certain age
YPPL
years of potential life lost
DALYs
disability-adjusted life years
YPLL
computed for each invididual in a population by subtracting that person’s life span from the average life expectancy of the population
DALYs
adds the time a person has a disability to the time lost to early death
Cohort study
start with a group of subjects who lack a positive history of the outcome of interest and are at risk for the outcome; include at least two observation points
Population-based cohort study
study that includes either an entire population or a representative sample of the population
Exposure-based cohort study
study conducive for rare exposures–certain groups, such as occupational groups, may have higher exposures than the general population to specific hazards
Prospective cohort study
study characterized by determination of exposure levels at baseline (present) and follow-up for occurrence of disease at some time i the future
Retrospective cohort study
study tha makes use of historical data to determine exposure level at some baseline in the past
Historical Prospective Cohort study
study that makes use of both retrospective features and prospective features; also known as an ambispective cohort study
Nested Case-Control Study
a type of case control-study in which cases and controls are drawn from the population in a cohort study
relative risk
(incidence rate in the exposed)/(incidence rate in the unexposed)
Risk of disease in exposed group
Ie
Risk of disease in unexposed group
Iu
Risk of disease in population
Ip
relative risk
Ie/Iu
attributable risk
Ie-Iu
attributable fraction
(Ie-Iu)/Ie
population attributable risk
Ip-Iu
Population attributable fraction
(Ip-Iu)/Ip3