Clinical Epidemiology

Question 1

Define Clinical epidemiology

Answer 1

This is a specialty area that involves application of epidemiology to screening, diagnosis,prognosis and treatment in clinical settings.

Question 2

What is the primary aim of Clinical epidemiology?

Answer 2

To promote quality of clinical and patient oriented healthcare.

Question 3

What does clinical epidemiology specifically focus on?

Answer 3

Focuses on patients patients and
application of epidemiologic methods to assess efficacy of
screening, diagnosis and treatment in clinical settings.

Question 4

What is classical epidemiology?

Answer 4

This is the study of health related events in the population.

Question 5

Define screening

Answer 5

Refers to processes of detecting disease among individuals in a population without signs of the health problem.
Done to reduce morbidity and mortality by identifying asymptomatic individuals.

Question 6

List the types of screening

Answer 6

•mass or population
•case finding
•selective screening and targeted screening
•multiphasic screening

Question 7

What does a base rate of 50% mean?

Answer 7

It means before the test is done,the probability of having the disease is,50%.

Question 8

What does a lower base rate mean?

Answer 8

It means there are fewer people who have the disease and the specificity will be higher.

Question 9

When are positive and negative likelihood ratios used?

Answer 9

If the base rate is less than ,50% meaning the sensitivity is low

Question 10

What are likelihood ratios less sensitive to?

Answer 10

Variations in base rates

Question 11

What happens when the base rate is 50%

Answer 11

Sensitivity,specificity, positive and negative likelihood ratios yield the same results.

Question 12

When are likelihood ratios preferred?

Answer 12

If the base rate is high or low.

Question 13

What does a positive likelihood ratio reflect?

Answer 13

The level of confidence we can have that a person who obtains a score in the affected range truly has the health problem.

Question 14

What does a negative likelihood ratio reflect?

Answer 14

The confidence that a score in the unaffected range comes from a person who truly does not have the health problem

Question 15

When do we use positive predictive values/negative predictive values?

Answer 15

When we have prevalence

Question 16

When do we use likelihood ratios?

Answer 16

When we have base rates.

Question 17

How do you interpret a positive likelihood ratio?

Answer 17

A value greater than or equal to 10 means very positive.
3 is moderate
1 is inconclusive

Question 18

How do you interpret a negative predictive value?

Answer 18

A value equal to or less than 0.10 is very negative.
0.30 is moderate
1 is inconclusive

Question 19

Define prognosis

Answer 19

The likely outcome of a disease

Question 20

What are prognostic indicators?

Answer 20

These tell the doctor the likely behavior or progress of a health problem.
For example case fatality rate.

Question 21

What do we use for acute conditions?

Answer 21

Case fatality rates

Question 22

What do we use for chronic conditions?

Answer 22

Survival rates

Question 23

Which model is used for analysing survival data?

Answer 23

Cox model (also called the proportional hazards model)

Question 24

Define Lead time bias

Answer 24

The inflation of survival when lead time is counted in the survival time.
This is when you die from a disease that you have been screened for.

Question 25

Define Lead time

Answer 25

Difference in time between date of diagnosis from screening and date of diagnosis without screening

Question 26

Define length bias

Answer 26

This refers to the fact that cases of a disease with a better prognosis are more likely to be identified than faster progressing cases of a disease with a poorer prognosis.

Question 27

Define over-diagnosis

Answer 27

Occurs when screening identifies an illness that would not have shown clinical signs before the person’s death from other causes

Question 28

Define serendipity

Answer 28

Chance finding

Question 29

If a cute is necessary but not possible should you screen?

Answer 29

No

Question 30

If a cute is not necessary but possible, should you screen?

Answer 30

No
(Waste of resources)

Question 31

If a cute is necessary and may be possible should you screen?

Answer 31

Yes

Question 32

What does outcomes research seek to understand?

Answer 32

Seeks to understand the end results of clinical practices and interventions.

Question 33

Define Overdiagnosis

Answer 33

When screening identifies an illness that
would not have shown clinical signs before the person’s death
from other causes.

Question 34

How do we avoid biases?

Answer 34

Use RANDOMIZED controlled trials.

Question 35

What does outcomes research seek to understand?

Answer 35

Seeks to understand end results of
clinical practices and interventions.

Question 36

Outcomes research has become
important in developing better ways to monitor and improve
clinical care based on what assumption?

Answer 36

That every intervention produces
changes that can be measured and can improve quality of
care.

Question 37

Define Prognostic indicators.

Answer 37

These tell the doctor the likely behavior or
progress of a health problem.

Question 38

Define Validity.

Answer 38

looks at how well the test actually measures
what it is supposed to measure.

Question 39

What disease is screened using a purified protein derivative (PPD)?

Answer 39

Tuberculosis

Question 40

What does reliability mean?

Answer 40

Consistency of the test results

Question 41

What does yield mean?

Answer 41

Refers to the amount of disease detected through the screening process that would not have been identified otherwise.

Question 42

Define mass screening

Answer 42

Refers to screening large groups of people regardless of whether they show symptoms,usually applied to populations.

Question 43

Define multiphasic screening

Answer 43

Involves using multiple tests during one visit to screen for different diseases or conditions.

Question 44

Define targeted screening

Answer 44

Involves screening specific groups of individuals who are at high risk for a particular condition.