Endemic means that a disease:
A.
Occurs clearly in excess of
normal expectancy
B. Is habitually present in human populations
C. Affects a large number of countries simultaneously
D. Exhibits a seasonal pattern
E. Is prevalent among animals
Table who ate egg salad & who did not
eat egg salad
Total number of persons who ate each
specified combination of food items
|
Ate
tuna
|
Did
not eat tuna
|
Ate
egg salad
|
75
|
100
|
Did
not eat egg salad
|
200
|
50
|
Total number of persons who ate each
specified combination of food items & who later became sick (with acute
sore throats)
|
Ate
tuna
|
Did
not eat tuna
|
Ate
egg salad
|
60
|
75
|
Did
not eat egg salad
|
70
|
15
|
What is the sore throat attack rate in
persons who ate both egg salad & tuna
a.
60/75
b. 70/200
c. 60/133
d. 60/275
e.
None of the above
According to the results shown in the
preceding tables, which of the following food items (or combination of food
items) is most likely to be infective?
a.
Tuna only
b.
Egg salad only
c.
Neither tuna nor egg salad
d.
Both tuna & egg salad
e.
Cannot be calculated from the
data
In the study of an outbreak of an
infectious disease, plotting an epidemic curve is useful because:
a.
It helps to determine what type
of an outbreak (e.g. single-source, person-to-person) has occurred
b.
It shows whether herd immunity
has occurred
c.
It helps to determine the
median incubation period
d.
A & c
e.
A,b, & c
Which of the following is characteristic of
a single-exposure, common-vehicle outbreak?
a.
Frequent secondary cases
b.
Increasing severity with
increasing age
c.
Explosive
d.
Cases include both people who have
been exposed & those who were not exposed
e.
All of the above
At an initial examination in Oxford, Mass
migraine headaches was found in 5 of 1,000 men aged 30 to 35 years & in 10
of 1,000 women aged 30 to 35 years. The inference that women have a two times
greater risk of developing headaches than do men in this group is:
A prevalence survey conducted from January
1 through December 31, 2012 identified 1,000 cases of schizophrenia in a city
of 2,000,000 persons. The incidence rate of schizophrenia in this population is
5/100,000 persons each year. What percent of the 1,000 cases were diagnosed in
2012?
Which of the following is an advantage of
active surveillance?
What would be the effect on age specific
incidence rate of uterine cancer if women with hysterectomies were excluded
from the denominator of the calculations, assuming that there are some women in
each age group who have had hysterectomies?2
A survey was conducted among the non-hospitalized
adult populations of the united states during 2008 through 20122. The results
from this survey are shown below.
Age
group
|
Persons
with HTN %
|
18-29
|
4
|
30-39
|
10
|
40-49
|
22
|
50-59
|
43
|
60-69
|
54
|
70
& older
|
64
|
The researchers stated that there was an
age related increase in the risk of hypertension in this population. You conclude that the researchers
interpretation:
Next two questions relate to the information
below:
Population of the city of Atlantis on March
30, 2012 = 183,000
No of new active cases of TB occurring
between January 1 & June 30, 2012 = 26
No of active TB cases according to the city
register on June 30, 2012 =264
The incidence rate of active cases for the
6 month period was:
The prevalence rate of active TB for the
month of June was:
The following two questions are based on
information provided below:
In an Asian country with a popularion of 6
million people, 60,000 deaths occurred during the year ending December 31,
2010. These included 30,000 deaths from cholera in 100,000 people who were sick
with cholera.
What was the cause specific mortality rate
from cholera in 2010?
What was the case fatality from cholera in
2010?
Case fatality:
Age adjusted death rates are used to:
The mortslity rate from disease X in city A
is 75/100,000 in persons 65 to 69 years old. The mortality rate from the same
disease in city b is 150/100,000 in persons 65 to 69 years old. The inference
that disease X is two times more prevalent in persons 65 to 69 years old in
city B than it is in persons 65 to 69 years old in city a is:
The incidence rate of a disease is five
imes greater in women thn in men, but the prevalences rates show no sex
difference. The best explantiaon is
that:
For a disease such as pancreatic cancer,
which is highly fatal & of short duration:
Incidence & mortality rates will be
similar
Annual Cancer Deaths in white Male workers
in two industries
|
|
Industry A
|
Industry
B
|
|
Cancer
site
|
#
of deaths
|
%
of all cancer deaths
|
#
of deaths
|
%
of all cancer deaths
|
Respiratory
system
|
180
|
33
|
248
|
45
|
Digestive
system
|
160
|
29
|
160
|
29
|
Genitourinary
|
80
|
15
|
82
|
15
|
All
other sites
|
130
|
23
|
60
|
11
|
Totals
|
550
|
100
|
550
|
100
|
Based on the preceding information, it was
concluded that workers in industry B are at higher risk of death from
respiratoy system cancer than workers in industry A. (Assume that the age
distributions of the workers in the two industries are nearly identical.)
Which of the following statements is true?
A program manager from an international
health funding agency needs to identify regions that would benefit from an
intervention aimed at reducing premature disability. The program manager asks a
health care consultant to develop a proposal using an index that would help her
make this decision. Which of the following would best serve this purpose?
The following are st&ardized mortality
ratios (SMRs) for lung cancer in Engl&:
St&ardized
mortality ratios
Occupation
|
1949-1960
|
1968-1979
|
Carpenters
|
209
|
135
|
Bricklayers
|
142
|
118
|
Based on the SMRs alone, it is possible to
conclude that:
A screening tests is used in the same way
in two similar populations, but the proportion of false positive results among
those who test positive in population A is lower than that among those who test
positive in population B. What is the likely explanation for this finding?
A physical examination & an audiometric
test were given to 500 persons with suspected hearing problems, of whom 300
were actually found to have them. The results of the examination were as
follows
Physical
examination
|
|
|
|
|
Hearing
Problems
|
Result
|
Present
|
Absent
|
Positive
|
240
|
40
|
Negative
|
60
|
160
|
Audiometric
Test
|
|
|
|
Hearing Problems
|
|
Result
|
Present
|
Absent
|
Positive
|
270
|
60
|
Negative
|
30
|
140
|
Compares with the physical examination ,
the audiometric test is:
Two pediatricians want to investigate a new
laboratory test that identifies strep infections. Dr. Kidd uses the st&ard
culture test, which has a sensitivity of 90% & a specificity of 96%, Dr.
Childs uses the new test which is 96% sensitive & 96% specific. If 200
patients undergo culture with both tests which of the following is correct?
Which of the following is a good index of
the severity of a short term acute disease?
A diagnostic test has been introduced that
will detect a certain disease 1 year earlier than it is usually detected. Which
of the following is most likely to happen to the disease within the 10 years
after the test is introduced? (Assume that early detection has no effect on the
natural history of the disease. Also assume that no changes in death
certification practices occur during the 10 years.
Which of the following statements about
relative survival rate is true?
Before reporting the results of this
survival analysis, the investigation compared the baseline characteristics of
the 42 persons who withdrew from the study before its end with those of the
participants who had complete follow up. This was done for which of the
following reasons:
The major purpose of r&om assignment in
a clinical trial is to:
An advertisement in a medical journal
stated that “2,000 subjects with sore throats were treated with our new
medicine, within 4 days 94% were asymptomatic” The advertisement claims that the
medicine was effective. Based on the evidence given above the claim:
The purpose of a double blind or double
masked study is to:
In many studies examining in the
association between estrogens & endometrial cancer of the uterus, a one
sided significance test was used. The underlying assumption justifying a
one-sided rather than a two-sided test is:
In a r&omized trial, a planned
crossover design:
A r&omized trial comparing the efficacy
of two drugs showed a difference between the two (with a P value <0.05).
Assume that in reality, however, the two drugs do not differ. This is therefore
an example of:
All of the following are potential benefits
of a r&omized control trial, except:
In cohort studies of the role of a
suspected factor in the etiology of a disease, it is essential that
Which of the following is not an advantage of a prospective cohort
study
Retrospective cohort studies are
characterized by all of the following except
A major problem resulting from the lack of
r&omization in a cohort study is:
In a cohort study, the advantage of
starting by selecting a defined population for study before any of its member
become exposed, rather than starting by selecting exposed & non-exposed
individuals is that:
A case control study is characterized by
all of the following except:
a)
It is relatively inexpensive
compared with most other epidemiologic studies
b) Patients with the disease (cases) are compared with persons without
the disease (controls)
c) Incidence rates may be computed differently
d) Assessment of past exposure may be biased
e) Definition of cases may be difficult
Residents of three villages with three
different types of water supply were asked to participate in a survey to
identify cholera carriers. Because several cholera deaths had occurred
recently, virtually everyone present at the time underwent examination. The
proportion of resident in each village who were carriers was computed &
compared. What is the proper classification for this study?
Which of the following is a case control
study?
In a study begin in 1965, a group of 3,000
adults in Baltimore were asked about alcohol consumption. The occurrence of
cases of cancer between 1981 & 1995 was studied in this group. This is an example of:
In a small pilot study, 12 women with
endometrial cancer & 12 women with no apparent disease were contacted &
asked whether they had ever used estrogen. Each woman with cancer was matched
by age, race, weight, & parity to a woman without the disease. What kind of
study design is this?
The physical examination records of the
entire incoming freshman class of 1935 at the University of Minnesota were
examined in 1977 to see if their recorded height & weight at the time of
admission to the university was related to the development of coronary artery
disease by 1968. This is an example of:
In a
case control study, which of the following is true?
a)
The proportion of cases with
the exposure is compared with the proportion of controls with exposure
b) Disease rates are compared for people with the factor of interest &
for people without the factor of interest
c) The investigator may choose to have multiple comparison groups
d)
Recall bias is a potential
problem
In which one of the following types of
study designs does a subject serve his own control?
Ecologic fallacy refers to:
In a study of disease in which all cases
that developed were ascertained, if the relative risk for the association
between a factor & the disease is equal to or less than 1.0, then:
Rates of ASHD per 10,000 population, by age
& sex, Framingham massachusetts
|
Mens
|
|
Womens
|
|
Age
at beginning of study
|
ASHF
rates at initial exam
|
Yearly
follow up exams
|
ASHD
rates at initial exam
|
Yearly
follow up exams
|
29-34
|
76.7
|
19.4
|
0.0
|
0.0
|
35-44
|
90.7
|
40.0
|
17.2
|
2.1
|
45-54
|
167.6
|
106.5
|
111.1
|
29.4
|
55-62
|
505.4
|
209.1
|
211.1
|
117.8
|
The relative risk for developing ASHD
subsequent to entering this study in men as compared to women is :
The most likely explanation for the
difference in rates of ASHD between the initial examination & the yearly
follow u exam in men is:
Several studies have found that
approximately 85% of cases of lung cancer are due to cigarette smoking. This
measure is an example of:
In a large case control study of patients
with pancreatic cancer, 17% of the patients were found to be diabetic at the
time of diagnosis compared to 4% of a well matched control group that was
examined for diabetes at the same time as the cases were diagnosed. It was
concluded that the diabetes played a causal role in the pancreatic cancer. This
conclusion is:
An investigator examined cases of fetal
death in 27,000 pregnancies & classified mothers according to whether they
had experienced intercourse within 1 month before delivery. It was found that
11% of the mothers fetuses that died & 2.5% of the mothers of the fetuses
that survived has had sexual intercourse during the period. It was concluded
that intercourse during the moth preceding the delivery caused the fetal
deaths. This conclusion
All of the following are important criteria
when making causal inferences except:
a)
Consistency with existing
knowledge
b) Dose-response relationship
c) Consistency of association in several studies
d) Strength of association
e)
Predictive values
Factor X is :
Factor A is: