FOM 2.4.3

Question 1

A study is conducted to determine the amount of people in the army with hearing loss. This is an example of what?

Answer 1

Prevalence

Question 2

Men and women who had normal hearing during the first examination are given hearing tests two years later. The number of these soldiers that have new onset hearing loss is an assessment of what?

Answer 2

Incidence

Question 3

What is observational vs experimental design?

Answer 3

Observational: examines conditions/events that already occurred or will occur anyways

Experimental: Conditions under the direct control of the investigator.

Question 4

What is directionality and what is the difference between forward and backwards?

Answer 4

Forward directionality is moving forward in time to see how a disease develops

Backwards is starting with the disease and going back to see what the possible risk factors were

Question 5

A non-directional study is often referred to as what?

Answer 5

Cross-sectional study

Question 6

What is an example of cross-sectional study?

Answer 6

Urine BPA levels in relation to obesity in school-age children

Baseball players developing mucosal lesions with or without chewing tobacco

Question 7

What are advantages of a cross-sectional study?

Answer 7

Convenient and inexpensive
Can evaluate several exposures/diseases
Can estimate population disease/ exposure

Question 8

What are disadvantages of a cross-sectional study?

Answer 8

Cannot establish whether exposure preceded disease or disease influenced exposure
Can identify only prevalence but not incidence
May miss disease with short duration

Question 9

What is an ecologic study?

Answer 9

Uses populations rather than individual people

Question 10

What are advantages of Ecologic studies?

Answer 10

Pre-existing data may exist
May help generate a hypothesis
Useful in evaluating effects of interventions at population level

Question 11

What is the main limitation of an ecological study?

Answer 11

Looks at the group overall and not individuals

Question 12

What is a case-control study?

Answer 12

Working back to see a place of exposure. Starts with a disease then obtain a history of exposure to find a possible relationship Ex Heat Related deaths during 1999 heat wave in chicago

Question 13

What are advantages of a case-control study?

Answer 13

Allows study of rarer diseases allows the study of several exposures at the same time.

Question 14

What are disadvantages of case-control?

Answer 14

Subject to systematic error or bias

Does not allow for the study of several diseases

Question 15

What is a cohort study?

Answer 15

Subjects are diesease free at baseline and must follow subject for an amount of time to see who develops a disease

Question 16

What is a prospective cohort?

Answer 16

The cohort is assembled in the present and followed into the future?

Question 17

What is a retrospective cohort?

Answer 17

The cohort is identified by past records and followed into the future

Question 18

What are some advantages of a cohort?

Answer 18

Ability to establish incidence due to forward directionality

Less prone to bias

Question 19

What are disadvantages?

Answer 19

Costly
Loss of subjects
Does not work with rare diseases

Question 20

What are disadvantages of observational studies?

Answer 20

How to deal with extraneous difference between exposed and non-exposed groups to mimic experiment

Question 21

Why is randomization critical in clinical research?

Answer 21

ensures the similarity of characteristics at start of comparison
Avoids bias on part of the investigator or patient

Question 22

What are goals of randomization?

Answer 22

Study groups should be comparable on all levels except for exposure status

Question 23

What is blinding and what are the levels of it?

Answer 23

Open, Single, and double

Degree of who knows what people are getting

Question 24

What is open label blinding?

Answer 24

Patient and physician know treatment assignment

Question 25

What is single-blinded?

Answer 25

Patient does not know treatment, but physician does

Question 26

What is double-blinding?

Answer 26

Neither patient nor physician know treatment assignment

Question 27

What is the placebo effect?

Answer 27

Pts who take a placebo report improvement up to 40% of the time

Question 28

What are the types of endpoints?

Answer 28

Binary- died vs lived; success vs failure

Survival - time to death, time to failure

Question 29

What is a systematic review?

Answer 29

A review of many literature that are relevant to the subject

Question 30

What is meta-analysis?

Answer 30

An statistical analysis of many results that are similar