Introduction to Pathology & Patient Care

Question 1

What is a prognosis?

Answer 1

likely outcome without treatment or with best treatment

Question 2

Define risk

Answer 2

exposures/events that can promote disease

Question 3

Define etiology

Answer 3

cause of disease

Question 4

Define pathogenesis

Answer 4

mechanisms of cause of disease

Question 5

Define pathophysiology

Answer 5

mechanisms of how disease progresses

Question 6

What are the kinds of pathological evaluations?

Answer 6

• autopsy
• organs (surgical removal)
• Tissues (biopsy)
• cells (cytology – fine needle aspiration or exfoliative)
• fluids

Question 7

What is clinical labratory medicine?

Answer 7

• typically dealing with patient fluids (blood, serum, etc)

- provides additional patient data and supports history, osteopathic structural exam, radiological studies, etc

Question 8

Why perform a clinical test?

Answer 8

• determine probability that patient has disease
• assess severity of disease
• predict outcome of disease (prognosis)
• monitor effectiveness of disease intervention

Question 9

Difference between a diagnosis and screening

Answer 9

Diagnosis is clinical test determining probability of disease in patient – greater confidence of diagnosis
Screening is clinical test determining probability of disease in population – determines who likely has it

Question 10

How do we use population data in medicine?

Answer 10

• better understanding of health and disease
• population-based decisions (preventative care)
• apply data to individual

Question 11

How do we determine if a test is abnormal?

Answer 11

if it is sufficiently outside the homeostatic range

Question 12

5 approaches to interpreting test results:

Answer 12

• reference range (most common)
• threshold to diagnose
• prognosis/desirable
• therapeutic range
• self-comparison

Question 13

Interpreting results: reference range

Answer 13

• random sampling of normal patients

- range of 95% of test results defines normal range

Question 14

Interpreting results: prognosis/desirable

Answer 14

(ideal is not necessarily normal)

• established based on desired levels - based upon knowledge of what’s healthy
• can’t use 95% because too many people are prognostically undesirable (cholesterol)

Question 15

Interpreting results: threshold to diagnose

Answer 15

-the normal is low or undetectable
-abnormal is above threshold of detection
-yields either positive or negative results (not range)
(pregnancy tests, creatinine kinase-MB)

Question 16

Interpreting results: therapeutic drug reference range

Answer 16

maximize benefit, minimize risk of toxicity

Question 17

Interpreting results: self-comparison

Answer 17

• not good for intial diagnosis
• not always present (tumor markers)
• use to follow treatment efficacy and monitor for reoccurence

Question 18

Define sensitivity

Answer 18

ability to accurately detect ALL those with the disease

-detect possible disease (screening)

Question 19

Define specificity

Answer 19

ability to accurate;y identify ALL those withOUT disease

-used to confirm diagnosis

Question 20

What is the ideal test threshold?

Answer 20

diagnostic threshold completely separates those with disease and those without

Question 21

What happens when you maximize sensitivity of a test?

Answer 21

• identify all those with disease correctly

- a lot of false positives

Question 22

What happens when you maximize specificity of a test?

Answer 22

• identifies all those without disease correctly

- a lot of false negatives

Question 23

Equation for specificity

Answer 23

true negative/(false positive + true negative)

Question 24

Equation for sensitivity

Answer 24

true positive/(false negative + true positive)

Question 25

sensitivity and sensitivity are not dependent on _________

Answer 25

disease prevalence

Question 26

What part of a test is dependent on disease prevalence?

Answer 26

utility (PPV and NPV)

Question 27

What is the pre-analytical phase?

Answer 27

• time from patient preparation through the time of sample collection until sample arrives in lab
• any errors here are due to people

Question 28

What is the analytical phase?

Answer 28

• time that the sample is being analyzed in the lab

- any errors here are due to technology

Question 29

What is the post-analytical phase?

Answer 29

• begins when result is generated and ends when the result is reported to ordering physician
• any errors here are due to people

Question 30

What are the pre-analytical variables that affect test results?

Answer 30

• age, gender, body mass of patient
• patient prep (not fasting, etc)
• drugs that interfere with testing process
• method of sample collection (patient posture for blood collection, differences in blood from different blood vessels)
• enough sample collection
• time for transport to the lab
• storage of sample before analyzation

Question 31

What are the analytical variables that affect test results?

Answer 31

(least common of the phases)

• use of instrument
• use of proper reagents
• incorporation of proper controls
• use of blood samples with hemolysis, elevated bilirubin, markedly elevated TAGs

Question 32

What are the post-analytical variables that affect test results?

Answer 32

• delay in time to enter results
• incorrect data entry
• reporting results to the wrong patient