Lecture 8-More on Study Designs in Epidemiology:Experimental Trials

Question 1

nested case control

Answer 1

case-control studies nested within defined cohort

• data= prospectively collected
• different from case-cohort study based on how control is selected
• people who have not developed the disease are those who become the control

Question 2

case-cohort study

Answer 2

-identify cases and control based on data collected prospectively on exposure and outcome
controls are randomly chosen from the defined cohort at the beginning of the study

Question 3

Advantages of embedding case-control study in defined cohort? case-cohort study

Answer 3

data is obtained from beginning of study

• avoid recall bias
• cost effective
• cases and controls are from the cohort you started with

Question 4

clinical trial

Answer 4

assign people to different treatment groups to see if occurrence of disease complication or recovery occurs
-example: Tamoxifen and recurrence of breast cancer(reduces recurrence of breast cancer

Question 5

What are the components of an Experimental study design?

Answer 5

• goal: test how well intervention prevents an outcome
• treatment is assigned by investigator ??(i thought in lecture we said this wasn’t the case, introduces bias)
• can apply to individuals or communities

Question 6

How do RCT(Randomized controlled trials) differ from Community trials?

Answer 6

RCT- exposure assigned to individuals

community trials- exposure is assigned to groups of people/community

Question 7

What are the different types of experimental trials?

Answer 7

1. clinical trials
2. prevention trials
3. diagnostic trials
4. screening trials
5. quality of life

Question 8

FDA Phases of Clinical trials

Answer 8

Phase I: used to test new treatments using very small group of people
Phase II: after phase I, a bigger group is used to test safety and effectiveness
Phase III: used to compare new treatment to new commonly used ones. Bigger group is used(3,000-6,000 ppl)
Phase IV: monitor effects of treatment and whether there are any side effects