Screening & Diagnostic Testing exam Questions with
Correct Answers
Question 1.
test
Correct Answer: - any critical examination, observation, or evaluation designed
to detect a substance or response.
- not just confined to a lab or biochemical process.
- use tests to determine both the health and disease outcomes, but also
potential exposures
Question 2.
examples of epidemiological tests
Correct Answer: - checking someone's heartbeat
- a visual assessment by a veterinarian for lameness in an animal
- a question on a survey
- the application of a "case definition
- " a laboratory blood serology process to determine whether an infection is
present
- the diagnostic ability of a person (e.g., psychologist).
Question 3.
categories of tests for health and disease outcomes
Correct Answer: 1) screening tests
2) diagnostic tests
Question 4.
screening test
Correct Answer: - generally used as a population approach on apparently
healthy individuals to detect subclinical
disease; it provides an early indication of a pathological disease process or
limited health/productivity
outcome.
Question 5.
diagnostic test
Correct Answer: - generally used on sick individuals (who are presenting
clinical signs and symptoms) to confirm,
classify, inform treatment, or provide a prognosis for a particular disease.
,Question 6.
prognosis
Correct Answer: a forecast of the probable course and outcome of a disease or
situation
Question 7.
biases in sceening
- lead time bias
- length time bias
- self-selection bias
Correct Answer: > all of these biases tend to make screening look more
successful than it might be
Question 8.
lead time bias
Correct Answer: - the period of time between the detection of a disease by
screening and when it would typically be
diagnosed because a patient experiences symptoms and seeks medical care.
- with screening we might detect this disease in someone earlier than they
would normally have found
out about it. If we follow along until this person dies, we might expect to see
that the period of
survival was longer than if the person waited to seek medical care when
clinical symptoms were
present.
- This would seem to suggest that early screening itself causes longer
survival times of disease
individuals.
- The difference is that early screening made the individual aware of the
issue and as a result, that
person sought treatment. It would then be the treatment efficacy that
resulted in a longer survival
time.
- The difference between when that person found about the disease through
screening, and the time
that this person would have found out about the disease if no screening
system were present, is the
lead time bias.
Question 9.
survival time
Correct Answer: - The time from when they sought medical treatment to when
they died would be characterized as
their "survival".
, Question 10.
length time bias
- those with longer pre-symptomatic periods (e.g. period of time where no symptoms
are present) are
over-represented in the screen population.
- This is because those with clinical disease will often seek diagnostic
procedures/treatment right
away, and as a result,
Correct Answer: are not often picked up in screening programs. > For example,
cancer that is found
in a screening program will be disproportionately slower growing than
normal. Slower growing
cancers tend to have better prognosis and longer patient survival time
compared to more aggressive
forms.
- Screening will typically over-estimate the duration of survival with a given
condition because there
is an excess of cases that exhibit slower growing cases. In other words, the
cases of disease in the
screening program are not representative of the true population of cases
Question 11.
self-selection bias
Correct Answer: - Volunteers are typically more educated, higher income and
social class, more motivated and
sociable, generally healthier, more likely to be female, and to adhere to
medical advice. As a result,
these individuals in a voluntary screening program are unlikely to be
representative of the larger
population and/or the true health status of that population.
Question 12.
two-by-two tables
Correct Answer: - They get their name from the fact that there are four cells in
each table, created by cross-tabulating a
binary health/disease outcome (diseased/not diseased) and binary exposure
(exposed/unexposed).
- Our recommended rule of thumb is to ALWAYS put your outcome on top of
the table (columns)
and ALWAYS put your exposure on the side of the table (rows).
Question 13.
gold standard
Correct Answer: - true measure of the outcome status in the population
Correct Answers
Question 1.
test
Correct Answer: - any critical examination, observation, or evaluation designed
to detect a substance or response.
- not just confined to a lab or biochemical process.
- use tests to determine both the health and disease outcomes, but also
potential exposures
Question 2.
examples of epidemiological tests
Correct Answer: - checking someone's heartbeat
- a visual assessment by a veterinarian for lameness in an animal
- a question on a survey
- the application of a "case definition
- " a laboratory blood serology process to determine whether an infection is
present
- the diagnostic ability of a person (e.g., psychologist).
Question 3.
categories of tests for health and disease outcomes
Correct Answer: 1) screening tests
2) diagnostic tests
Question 4.
screening test
Correct Answer: - generally used as a population approach on apparently
healthy individuals to detect subclinical
disease; it provides an early indication of a pathological disease process or
limited health/productivity
outcome.
Question 5.
diagnostic test
Correct Answer: - generally used on sick individuals (who are presenting
clinical signs and symptoms) to confirm,
classify, inform treatment, or provide a prognosis for a particular disease.
,Question 6.
prognosis
Correct Answer: a forecast of the probable course and outcome of a disease or
situation
Question 7.
biases in sceening
- lead time bias
- length time bias
- self-selection bias
Correct Answer: > all of these biases tend to make screening look more
successful than it might be
Question 8.
lead time bias
Correct Answer: - the period of time between the detection of a disease by
screening and when it would typically be
diagnosed because a patient experiences symptoms and seeks medical care.
- with screening we might detect this disease in someone earlier than they
would normally have found
out about it. If we follow along until this person dies, we might expect to see
that the period of
survival was longer than if the person waited to seek medical care when
clinical symptoms were
present.
- This would seem to suggest that early screening itself causes longer
survival times of disease
individuals.
- The difference is that early screening made the individual aware of the
issue and as a result, that
person sought treatment. It would then be the treatment efficacy that
resulted in a longer survival
time.
- The difference between when that person found about the disease through
screening, and the time
that this person would have found out about the disease if no screening
system were present, is the
lead time bias.
Question 9.
survival time
Correct Answer: - The time from when they sought medical treatment to when
they died would be characterized as
their "survival".
, Question 10.
length time bias
- those with longer pre-symptomatic periods (e.g. period of time where no symptoms
are present) are
over-represented in the screen population.
- This is because those with clinical disease will often seek diagnostic
procedures/treatment right
away, and as a result,
Correct Answer: are not often picked up in screening programs. > For example,
cancer that is found
in a screening program will be disproportionately slower growing than
normal. Slower growing
cancers tend to have better prognosis and longer patient survival time
compared to more aggressive
forms.
- Screening will typically over-estimate the duration of survival with a given
condition because there
is an excess of cases that exhibit slower growing cases. In other words, the
cases of disease in the
screening program are not representative of the true population of cases
Question 11.
self-selection bias
Correct Answer: - Volunteers are typically more educated, higher income and
social class, more motivated and
sociable, generally healthier, more likely to be female, and to adhere to
medical advice. As a result,
these individuals in a voluntary screening program are unlikely to be
representative of the larger
population and/or the true health status of that population.
Question 12.
two-by-two tables
Correct Answer: - They get their name from the fact that there are four cells in
each table, created by cross-tabulating a
binary health/disease outcome (diseased/not diseased) and binary exposure
(exposed/unexposed).
- Our recommended rule of thumb is to ALWAYS put your outcome on top of
the table (columns)
and ALWAYS put your exposure on the side of the table (rows).
Question 13.
gold standard
Correct Answer: - true measure of the outcome status in the population
