BATES' GUIDE TO PHYSICAL
EXAMINATION AND HISTORY TAKING
CH. 1-5 EXAM QUESTIONS AND
ANSWERS 2026 VERIFIED.
Validity - ANS Does the test accurately identify whether a patient has a disease?
This involves comparing the test against a "gold standard" (the best measure of wether a
patient has disease).
The initial step in evaluating a diagnostic test.
Sensitivity - ANS 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.
Specificity - ANS The probability that a non-diseased person has a NEGATIVE test.
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,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.
A negative result from a test with high sensitivity... - ANS ...usually means you can exclude
the disease.
(high sensitivity = very low false-negative rate)
SnNOUT Acronym - ANS a Sensitive test with a Negative result rules OUT disease
SpPIN Acronym - ANS a Specific test with a Positive result rules IN disease
Positive Predictive Value (PPV) - ANS 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.
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, Negative Predictive Value (NPV) - ANS 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.
Prevalence of a disease - ANS The proportion of subjects that have the disease
Likelihood Ratios - ANS 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.
Likelihood ratio (LR) for a positive test - ANS 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
Likelihood Ratio (LR) for a negative test - ANS 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
LRs 1-2 and 0.5-1 - ANS Alter the probability (pre-test to post-test) to a small degree that is
very rarely important
LRs > 10 or < 0.1 - ANS Generate large changes
LRs > 1 - ANS Associated with positive results and an increased probability for disease
@COPYRIGHT ALL RIGHTS RESERVED PAGE 3 OF 16
EXAMINATION AND HISTORY TAKING
CH. 1-5 EXAM QUESTIONS AND
ANSWERS 2026 VERIFIED.
Validity - ANS Does the test accurately identify whether a patient has a disease?
This involves comparing the test against a "gold standard" (the best measure of wether a
patient has disease).
The initial step in evaluating a diagnostic test.
Sensitivity - ANS 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.
Specificity - ANS The probability that a non-diseased person has a NEGATIVE test.
@COPYRIGHT ALL RIGHTS RESERVED PAGE 1 OF 16
,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.
A negative result from a test with high sensitivity... - ANS ...usually means you can exclude
the disease.
(high sensitivity = very low false-negative rate)
SnNOUT Acronym - ANS a Sensitive test with a Negative result rules OUT disease
SpPIN Acronym - ANS a Specific test with a Positive result rules IN disease
Positive Predictive Value (PPV) - ANS 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.
@COPYRIGHT ALL RIGHTS RESERVED PAGE 2 OF 16
, Negative Predictive Value (NPV) - ANS 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.
Prevalence of a disease - ANS The proportion of subjects that have the disease
Likelihood Ratios - ANS 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.
Likelihood ratio (LR) for a positive test - ANS 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
Likelihood Ratio (LR) for a negative test - ANS 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
LRs 1-2 and 0.5-1 - ANS Alter the probability (pre-test to post-test) to a small degree that is
very rarely important
LRs > 10 or < 0.1 - ANS Generate large changes
LRs > 1 - ANS Associated with positive results and an increased probability for disease
@COPYRIGHT ALL RIGHTS RESERVED PAGE 3 OF 16
