module 5

Question 1

whenn is quasi experiments used

Answer 1

under conditions where true experimental designs are not possible or are too expensive

cannot be usedd to infer causation as conclusively as true experiantal trials since it has a poorer internal validity

most used if:
- control is exerted where possible
- masking (blinding procedures are used)

Question 2

what is missing in a quasi-expernimental research

Answer 2

control group

random assighnment or both

Question 3

what are the weaknesses and why might you use a of a non-equivalent pre-test -post-test control group design ( no random assighnment)

Answer 3

weaknesses: the groups might not be equivalent, howewever ther was a pre-test

might use it when you have pre-existing groups (e.g. grade 3 classroom)

Question 4

weaknesses and when to use a one group pre-test-post-test design ( no random assighnment and no control group, no supplementation)

Answer 4

• no control grouop - poor internal validity

when to use
- it is ethical
- time frame is really short

Question 5

what can the repeated measures in a quasi-expermental design have

Answer 5

• pre/post
  -interim assesment(s)
  -follow-up assesment(s)

Question 6

time-series design what it is what type and how it can be a quasi-experimental design

Answer 6

• multiple measures to doccument patterns or trends in behaviour ober time
• purpose is to determine trend in outcome overtime
• it is a observational study
• in order to be a quasi-experimental design it needs to be manipulate variables, control

Question 7

interrupted time-series design

Answer 7

time series is “ interrupted” by an intervention within the series of measurements

used for population level interventions
- randomization not generally possible, thus, quasi-experimental
- may or may not have a control group

Question 8

advantages of time series

Answer 8

multiple measurements enhances confidence that there was a real change
- versus normal variation
-versus repeated testing effects -> learning by doing repeated testing

Question 9

disadvantes time series

Answer 9

• lack of randomization and /or control still reduces internal validity relative to experimental design
• also, may be a confounding (e.g., historical) event that occurred at same time as intervention

Question 10

randomize controoled trial

Answer 10

a study design that randomly assigns participants into an experimental group or a control group. as the study is conducted, the only expected difference between the control and experimental groups in a randomized controlled trial (RCT) is the outcome variable bieng studied

Question 11

randomized clinical trial

Answer 11

A study in which the participants are divided by chanve into seperate groups that compare different treatmentsor other interventions. using chance to divide people into groups means that the groups will be similar and that effects pf the treatments they can be compared fairly. at the time of the trial, it is not known which treatmeent is best

Question 12

clinical trial

Answer 12

A research study in which one or more human subjects are propectively assigned to one or more interventions (which may include placebo or other control) to evaluate the eddects of those more interventions on health-related biomedical or behavioral outcomes.

Question 13

phases of the clinical trial

Answer 13

preclinical trail
- phase 0 trial
- Phase 1 trial
- Phase II trial
- Phase III trial
- Phase IV trial

Question 14

preclinical trial

Answer 14

• non-human in labrotory conditions
• screens many potetial compounds
• if promising, request to move to human trials

Question 15

Phase 0 trial

Answer 15

• First trial in humans
• very small number of healthy people (n = 10-15)
• very small dose to ensure safety

Question 16

Phase I trial

Answer 16

• Determines the largest dose without serious side effects
• Larger sample of healthy adults, but still reletively small (N=50-200)
• Dosage, timing, side effects

Question 17

Phase II trial

Answer 17

• given dose found to be most beneficial in Phase I
• small sample of people with disease/at risk for disease
• effec should be greater or equal to standard treatment to continue trials

Question 18

Phase III trials

Answer 18

• Randomized controlled trial (masked/ blinded)
• Large studies with thousands of participants - years
• New therapy vs. Standard treatment /placebo
  approval occurs between phase III trials and Phase IV trial

Question 19

Phase IV trial

Answer 19

• post aproval
• alternate populations
• Risk factors, benefits, optimal use

Question 20

type of research in quasi-experimental group

Answer 20

preclinical
phase 0 trial
phase I trial

Question 21

quasi-experimental or experimental (drug vs. usual care)

Answer 21

Phase II trial

Question 22

Experimental (RCT, Placebo, blinded)

Answer 22

Phase III trial
Phase IV trial