Epidemiology 2 Exam With Questions And 100%
Correct Answers
Experimental ANSWER Subjects were children enrolled in a health maintenance
organization. At 2 months, each child was randomly given one of two types of a new
vaccine against rotavirus infection. Parents were called by a nurse two weeks later and
asked whether the children had experienced any of a list of side-effects.
Experimental ANSWER A study in which children are randomly assigned to receive
either a newly formulated vaccine or the currently available vaccine, and are followed to
monitor for side effects and effectiveness of each vaccine.
Cohort ANSWER The Iowa Women's Health Study, in which researchers enrolled 41,837
women in 1986 and collected exposure and lifestyle information to assess the
relationship between these factors and subsequent occurrence of cancer.
Cohort - QUESTION Cancer incidence was ascertained between April 1991 and July
2002 for the 50,000 personnel serving in the first Gulf War (ended April 1991) and 50,000
personnel serving elsewhere during this time.
Case-control ANSWER Persons with newly diagnosed Lyme disease were interviewed
regarding frequency of walks through woods, use of insect repellant, short sleeves and
pants, etc. Twice as many persons not with Lyme disease from the same physician's
practice were likewise interviewed and the responses in the two groups compared.
Cross-sectional - ANSWER Representative sample of residents were telephoned and
asked how much they exercise each week and whether they currently have (have ever
been diagnosed with) heart disease
Case Control - ANSWER British investigators conducted a study to compare
measles-mumps-rubella (MMR) vaccine history among 1,294 children with pervasive
development disorder (e.g., autism and Asperger's syndrome) and 4,469 children
, without such disorders. (They found no association.) This is an example of which type(s)
of study?
Cohort study vs case -control study - ANS Subjects are enrolled or categorized on the
basis of their exposure status in a cohort study but not in a case-control study
key feature of cross-sectional study - ANS -It usually provides information on prevalence
rather than incidence
-It is more useful for descriptive epidemiology than it is for analytic epidemiology
-It is synonymous with survey
Epidemiologic triad of disease causation refers to - ANSWER Agent, host and
environment
The hallmark feature of an analytic epidemiologic study - ANSWER Use of an
appropriate comparison group to estimate counterfactual scenario
Vaccine efficacy measures - ANSWER The proportionate reduction in disease among
vaccinees.
Confounding - ANSWER a distortion of the association between an exposure and an
outcome that occurs when the study groups differ with respect to other factors that
influence the outcome.
Confounder - ANSWER an extraneous variable that wholly or partially accounts for the
observed effect of a risk factor on disease status. The presence of a confounder can
lead to inaccurate results.
Three conditions that must exist to have confounding: - ANSWER 1. The confounding
factor has to be associated with both the risk factor under study and the outcome.
2. The confounding factor must be distributed unevenly among groups being compared.
Correct Answers
Experimental ANSWER Subjects were children enrolled in a health maintenance
organization. At 2 months, each child was randomly given one of two types of a new
vaccine against rotavirus infection. Parents were called by a nurse two weeks later and
asked whether the children had experienced any of a list of side-effects.
Experimental ANSWER A study in which children are randomly assigned to receive
either a newly formulated vaccine or the currently available vaccine, and are followed to
monitor for side effects and effectiveness of each vaccine.
Cohort ANSWER The Iowa Women's Health Study, in which researchers enrolled 41,837
women in 1986 and collected exposure and lifestyle information to assess the
relationship between these factors and subsequent occurrence of cancer.
Cohort - QUESTION Cancer incidence was ascertained between April 1991 and July
2002 for the 50,000 personnel serving in the first Gulf War (ended April 1991) and 50,000
personnel serving elsewhere during this time.
Case-control ANSWER Persons with newly diagnosed Lyme disease were interviewed
regarding frequency of walks through woods, use of insect repellant, short sleeves and
pants, etc. Twice as many persons not with Lyme disease from the same physician's
practice were likewise interviewed and the responses in the two groups compared.
Cross-sectional - ANSWER Representative sample of residents were telephoned and
asked how much they exercise each week and whether they currently have (have ever
been diagnosed with) heart disease
Case Control - ANSWER British investigators conducted a study to compare
measles-mumps-rubella (MMR) vaccine history among 1,294 children with pervasive
development disorder (e.g., autism and Asperger's syndrome) and 4,469 children
, without such disorders. (They found no association.) This is an example of which type(s)
of study?
Cohort study vs case -control study - ANS Subjects are enrolled or categorized on the
basis of their exposure status in a cohort study but not in a case-control study
key feature of cross-sectional study - ANS -It usually provides information on prevalence
rather than incidence
-It is more useful for descriptive epidemiology than it is for analytic epidemiology
-It is synonymous with survey
Epidemiologic triad of disease causation refers to - ANSWER Agent, host and
environment
The hallmark feature of an analytic epidemiologic study - ANSWER Use of an
appropriate comparison group to estimate counterfactual scenario
Vaccine efficacy measures - ANSWER The proportionate reduction in disease among
vaccinees.
Confounding - ANSWER a distortion of the association between an exposure and an
outcome that occurs when the study groups differ with respect to other factors that
influence the outcome.
Confounder - ANSWER an extraneous variable that wholly or partially accounts for the
observed effect of a risk factor on disease status. The presence of a confounder can
lead to inaccurate results.
Three conditions that must exist to have confounding: - ANSWER 1. The confounding
factor has to be associated with both the risk factor under study and the outcome.
2. The confounding factor must be distributed unevenly among groups being compared.
