Lecture 6, part 1

Question 1

What is a trial? What is the design?

Answer 1

A planned experiment
Designed specifically to evaluate the efficacy of a tx or intervention

Question 2

What does the investigator do in a trial?

Answer 2

Manipulates the exposure- compare outcomes in a group with intervention to outcomes in a comparable group without intervention

Question 3

What are common types of trials?

Answer 3

Field
Community
Clinical

Question 4

More details about field trials

Answer 4

Preventive interventions at the individual levle
Carried out in the field, on people who are not pts (initially dz-free)

Question 5

Definition of community trials

Answer 5

Preventive intervention applied to groups of ppl

Question 6

Definition of clinical trials

Answer 6

Therapeutic intervention applied to pts

Question 7

What do clinical trials do? What is the aim?

Answer 7

Experiment with pts (ppl who already have the dz/outcome) as subjects, generally aimed at preventing various sequelae

Question 8

What do clinical trials include?

Answer 8

Uncontrolled trials
Non-randomized control trials
Randomized control trials

Question 9

Why are trials useful?

Answer 9

Evaluate the efficacy of new drugs or other txs for dz
Evaluate new medical/healthcare tech
Evaluate new methods of prevention
Evaluate new programs for screening and dx
Evaluate new methods of providing care
Evaluate new healthcare policies

Question 10

How trials are designed

Answer 10

The population is divided into eligible and not eligible
The eligible participants are divided into intervention/tx and placebo/usual care groups
Both intervention/tx and placebo/usual care groups are monitored to see whether or not the outcome develops

Question 11

A trial is essentially a _______ _______ _______ except that the investigator manipulates the exposure.

Answer 11

Prospective cohort study

Question 12

What should be considered with the placebo group?

Answer 12

Whether use is ethical
If not ethical, compare new tx to standard tx

Question 13

What outcomes could be measured?

Answer 13

Dz
Recurrence of dz
A precursor to dz
Improved quality of life
All need to be measurable and well-defined before starting the study

Question 14

Why are comparison groups necessary?

Answer 14

Want to be able to derive a causal interference regarding the relationship between a tx and a subsequent outcome
Without a comparison group, we cannot attribute any improvement (or decline) in condition to the administration of the tx rather than other sources

Question 15

What is investigated in prevention trials?

Answer 15

Measures that prevent dz occurrence (primary prevention)

Question 16

What is investigated in therapeutic trials?

Answer 16

A measure that treats an existing condition (secondary prevention)

Question 17

Purpose of a prevention trial

Answer 17

Removal of a causal factor, addition of an agent, or behavior modification

Question 18

Purpose of a therapeutic trial

Answer 18

Txs or interventions intended to reduce recurrence, improve survival, or improve quality of life

Question 19

Among whom is a prevention trial conducted?

Answer 19

The general pop or high-risk individuals

Question 20

Among whom is a therapeutic trial conducted?

Answer 20

Pts or individuals with the condition of interest

Question 21

Parallel experimental trial design

Answer 21

Each group receives one tx
Txs are administered concurrently

Question 22

Crossover experimental trial design

Answer 22

Each group receives all txs one after another
The tx order differs for each group
Washout period may intervene between txs

Question 23

Simple experimental trial design

Answer 23

Each group gets one tx or intervention

Question 24

Factorial experimental trial design

Answer 24

Each group gets two or more txs or interventions

Question 25

Steps in conducting a randomized control trial

Answer 25

Select a sample
Randomize study participants
Measure baseline variables
Apply the intervention
Measure the outcome
Analyze the results