Answer Happy

A.
The study group receives the vaccine and the control group
receives a placebo.
B.
Neither observers nor subjects know the nature of the
placebo.
C.
Neither observers nor subjects know which subject receives the
vaccine and which receives the placebo.
D.
Neither the study group nor the control group knows the identity
of the observers.
E.
The control group does not know the identity of the study
group.
QUESTION 4
A.
The population to be followed is representative of the general
population.
B.
The persons with and without the factor under study are
comparable in other relevant respects.
C.
There are equal numbers of persons with and without the factor
under study.
QUESTION 15
A.
There is a relation between the use of gloves and the incidence
of staphylococcal infections.
B.
There is no relation between the use of gloves and the incidence
of staphylococcal infections.
C.
The relation between the use of gloves and the incidence of
staphylococcal infections can not been determined with only this
information..
D.
The difference is due to chance variations.
A.
The same for all
diseases
B.
<1 year, 1 to 4 years, 5 to 9 years, 10 to 14 years, 15 to 19
years, and 20 years for communicable diseases, but not necessarily
for chronic diseases
C.
Appropriate for each condition and narrow enough to detect any
age-related patterns present in the data
D.
5-year age groups for all diseases unless the data suggest the
need for narrower categories to find a pattern or aberrancy
QUESTION 20
A.
Achieve comparability of cases and controls.
B.
Reduce the effects of sampling variation.
C.
Avoid observer bias and interviewee bias.
D.
Avoid observer bias and sampling variation.
E.
Avoid interviewee bias and sampling variation.
QUESTION 23
A.
Both prospective and retrospective studies.
B.
Prospective studies.
C.
Retrospective studies.
D.