BATES Guide TO Physical Exam History
Taking Final Exam KEY APLUS Questions
and Answers Verified Solutions Latest Update
2026/2027
Question:
Sensitivity.
Answer:
The probability that a person with disease has a POSITIVE test.
Also known as the "true positive" rate.
Useful for screening tests because if sensitivity is > 90%, you can rule OUT diseases (test is rarely
negative when the disease is present)
Ex) The probability that a patient with splenomegaly is associated with percussion dullness below
the left costal margin.
Question:
Specificity.
Answer:
The probability that a non-diseased person has a NEGATIVE test.
Also known as the "true negative" rate.
Useful as confirmatory tests because if specificity is >90%, it is safe to confirm diseases (test is
rarely positive when the disease is absent)
Ex) The probability that a patient WITHOUT splenomegaly will have percussion dullness is the
false positive rate for this physical maneuver.
Question:
A negative result from a test with high sensitivity....
Answer:
...usually means you can exclude the disease.
(high sensitivity = very low false-negative rate)
,Question:
SnNOUT Acronym.
Answer:
a Sensitive test with a Negative result rules OUT disease
Question:
SpPIN Acronym.
Answer:
a Specific test with a Positive result rules IN disease
Question:
Positive Predictive Value (PPV).
Answer:
The probability that a person with a positive test has disease [a / (a + b)]
Ex) Prostate Cancer screening, where a man with a PSA value greater than 4.0 ng/mL has only a
30% probability of having prostate cancer when tested via biopsy.
The predictive value will vary substantially according to the prevalence of disease.
Question:
Negative Predictive Value (NPV).
Answer:
The probability that a person with a negative test does not have disease [d / (c + b)]
Ex) Among men with a PSA level of 4.0 ng/mL or below, 85% are found to be cancer-free via
biopsy.
Question:
Prevalence of a disease.
Answer:
, The proportion of subjects that have the disease
Question:
Likelihood Ratios.
Answer:
The probability of obtaining a given test result in a diseased patient DIVIDED BY the probability
of obtaining a given test result in a non-diseased patient.
This ratio tells us how much a test result changes the pre-test disease probability (prevalence) to the
post-test disease probability.
Question:
Likelihood ratio (LR) for a positive test.
Answer:
a HIGHER value (much greater than 1) indicates that a positive test is much more likely to be
coming from a diseased person than from a non-diseased person, increasing our confidence that a
person with a positive result has the disease
Question:
Likelihood Ratio (LR) for a negative test.
Answer:
a LOWER value (much less than 1) indicates that the negative test is much more likely to be
coming from a non-diseased person than from a diseased person, increasing our confidence that a
person with a negative result does NOT have the disease
Question:
LRs 1-2 and 0.5-1.
Answer:
Alter the probability (pre-test to post-test) to a small degree that is very rarely important
Question:
Taking Final Exam KEY APLUS Questions
and Answers Verified Solutions Latest Update
2026/2027
Question:
Sensitivity.
Answer:
The probability that a person with disease has a POSITIVE test.
Also known as the "true positive" rate.
Useful for screening tests because if sensitivity is > 90%, you can rule OUT diseases (test is rarely
negative when the disease is present)
Ex) The probability that a patient with splenomegaly is associated with percussion dullness below
the left costal margin.
Question:
Specificity.
Answer:
The probability that a non-diseased person has a NEGATIVE test.
Also known as the "true negative" rate.
Useful as confirmatory tests because if specificity is >90%, it is safe to confirm diseases (test is
rarely positive when the disease is absent)
Ex) The probability that a patient WITHOUT splenomegaly will have percussion dullness is the
false positive rate for this physical maneuver.
Question:
A negative result from a test with high sensitivity....
Answer:
...usually means you can exclude the disease.
(high sensitivity = very low false-negative rate)
,Question:
SnNOUT Acronym.
Answer:
a Sensitive test with a Negative result rules OUT disease
Question:
SpPIN Acronym.
Answer:
a Specific test with a Positive result rules IN disease
Question:
Positive Predictive Value (PPV).
Answer:
The probability that a person with a positive test has disease [a / (a + b)]
Ex) Prostate Cancer screening, where a man with a PSA value greater than 4.0 ng/mL has only a
30% probability of having prostate cancer when tested via biopsy.
The predictive value will vary substantially according to the prevalence of disease.
Question:
Negative Predictive Value (NPV).
Answer:
The probability that a person with a negative test does not have disease [d / (c + b)]
Ex) Among men with a PSA level of 4.0 ng/mL or below, 85% are found to be cancer-free via
biopsy.
Question:
Prevalence of a disease.
Answer:
, The proportion of subjects that have the disease
Question:
Likelihood Ratios.
Answer:
The probability of obtaining a given test result in a diseased patient DIVIDED BY the probability
of obtaining a given test result in a non-diseased patient.
This ratio tells us how much a test result changes the pre-test disease probability (prevalence) to the
post-test disease probability.
Question:
Likelihood ratio (LR) for a positive test.
Answer:
a HIGHER value (much greater than 1) indicates that a positive test is much more likely to be
coming from a diseased person than from a non-diseased person, increasing our confidence that a
person with a positive result has the disease
Question:
Likelihood Ratio (LR) for a negative test.
Answer:
a LOWER value (much less than 1) indicates that the negative test is much more likely to be
coming from a non-diseased person than from a diseased person, increasing our confidence that a
person with a negative result does NOT have the disease
Question:
LRs 1-2 and 0.5-1.
Answer:
Alter the probability (pre-test to post-test) to a small degree that is very rarely important
Question:
