chap 9

Question 1

used to identify riskfactors,andtoestimate the quantitative effects of thevariouscomponentcauses that contribute to the occurrence of disease.

Answer 1

observational studies

Question 2

_____ the investigator is not freetoallocatefactors to individuals, whereas in ______ theinvestigator is free to allocate factors to individualsatrandom.

Answer 2

observational studies, experimental studies

Question 3

a groupof animals exposedtoahypothesized causal factor (HCF), and a group not exposedtothefactor are selected and observed to record developmentofdiseasein each group. Therefore, (a + b) and (c + d) are predetermined

Answer 3

cohort study

Question 4

a group of diseased animals(case)andagroup of non-diseased animals (controls) are selectedandcompared with respect to presence of the hypothesizedriskfactor. Therefore, (a + c) and (b + d) are predetermined

Answer 4

case-control study

Question 5

involves the selectionof asampleofnindividuals from a sample of a larger population, andthenthedetermination, for each individual, of the simultaneouspresenceor absence of disease and hypothesized causal factor.

Answer 5

cross sectional study

Question 6

Classification
- Analytic, Observational, Prospective, Longitudinal,
Exposure-based
Study population
- Exposed grp and Unexposed grp
(both free of disease of interest!)
Objective
- to show that the probability of disease is higher inExposedgroup than in Unexposed group

Answer 6

cohort study AKA prospective study, incidence study, follow up study, longitudinal study

Question 7

grp of people who share the samechar.

Answer 7

cohort

Question 8

fixed grp ffd up fromacertainpointintime until a defined endpoint w/o losses tofollowup(note:event that signals entry into the cohort occurs onlyonceatacertain point in time); e.g. people who consumedaparticularfood

Answer 8

closed fixed cohot

Question 9

persons enter or leavethestudyanytime; changing exposures; e.g. smokers, vegetarians

Answer 9

open or dynamic cohort

Question 10

– exposed and unexposed groups are followedupovertimeforthedevelopment of disease of interest – Study participants are free of dz, and at risk of dev’gddz

Answer 10

prospective cohort

Question 11

individuals who are free of the dz/outcome of interestatsomepoint in the past are identified and classified accordingtoexposurelevels – the specified follow up period has elapsed, bothdiseaseandoutcome status of subjects have occurred
– efficient for rare disease with long induction pd

Answer 11

retrospective cohort