Lecture 16 9/23/24

Question 1

What are the characteristics of randomized controlled trials?

Answer 1

-gold standard for evaluating efficacy of therapeutic and preventive interventions
-all participants have the same chance of being assigned to each of the study groups

Question 2

What should be considered before a clinic becomes a trial participant site?

Answer 2

-formally stated protocol
-protocol freely provided to enrollees upon request
-appropriate review of the study
-enrollment expectations and time commitments for enrollees and clinicians

Question 3

What needs to be included in the protocol for a clinical trial?

Answer 3

-rationale/background
-specific objectives
-statement of design
-inclusion/exclusion criteria
-outline of treatment procedure
-definition of clinical and lab. methods
-methods
-major and minor endpoints
-provisions for observing/recording side effects
-procedures for handling problems
-procedure for informed consent
-sample size calculations and plan for analyzing results
-forms and support letters

Question 4

Which steps should occur prior to study enrollment?

Answer 4

-study design and funding
-protocol and forms creation
-clearance process

Question 5

What are the challenges that complicate study enrollment?

Answer 5

-researcher availability at enrollment site
-willingness of potential participant to be contacted
-additional time required to discuss and consent
-combination of clinical knowledge and interpersonal skills

Question 6

What must be included on the owner consent form?

Answer 6

-purpose of study
-expected duration of participation
-possible discomforts/risks
-treatment and potential benefits
-alternative treatment
-financial obligations
-disclosure of results
-right to withdraw
-termination of participation by investigator
-written consent

Question 7

What is the most important aspect of owner’s consent?

Answer 7

owners understanding the risk and benefits

Question 8

What are the important features of randomized clinical trials?

Answer 8

-randomization
-blinding

Question 9

What are the characteristics of randomization?

Answer 9

-ensures that groups in clinical trials are comparable
-reduces risk of selection bias
-most powerful method of eliminating known and unknown confounding variables

Question 10

What is the benefit of stratified randomization?

Answer 10

ensures balanced groups that are both equal in size and with regard to potential confounders

Question 11

What is parallel-group study design?

Answer 11

participants are randomly assigned to groups; all participants in the group receive or do not receive intervention

Question 12

What is crossover study design?

Answer 12

participants receive or do not receive intervention in a random sequence over time

Question 13

What is cluster study design?

Answer 13

pre-existing participant groups randomly selected to receive or not receive intervention

Question 14

What is factorial study design?

Answer 14

participants randomly assigned to group that receives a particular combination of interventions or non-interventions

Question 15

What are the characteristics of an explanatory outcome RCT?

Answer 15

-tests efficacy of an intervention in research setting
-rigorously selected participants
-highly controlled conditions

Question 16

What are the characteristics of a pragmatic outcome RCT?

Answer 16

-tests effectiveness of intervention in everyday practice
-relatively unselected participants
-flexible conditions

Question 17

What is a superiority trial?

Answer 17

one intervention is hypothesized to be superior to another in a statistically significant way

Question 18

What is a non-inferiority trial?

Answer 18

determine whether a new treatment is no worse than a reference treatment

Question 19

What is an equivalence trial?

Answer 19

tests hypothesis that two interventions are indistinguishable

Question 20

What are the comparison group types?

Answer 20

-no intervention
-observation
-placebo treatment
-standard treatment

Question 21

What are the characteristics of the no-intervention group?

Answer 21

-control group receives no intervention whatsoever
-can have a historically controlled study when comparing intervention groups with a similar group from the past who received no interventions

Question 22

What are the characteristics of the observation group?

Answer 22

-control group does not receive any intervention AND is carefully monitored
-helps account for Hawthorne effect

Question 23

What is the Hawthorne effect?

Answer 23

observed effect attributable to being included in a scientific study; knowledge of study participation influences behavior

Question 24

What are the characteristics of the placebo treatment group?

Answer 24

-placebo is an inactive substance given as a comparison to the treatment under study
-unethical to withhold treatment via use of placebo for life-threatening/serious illness; must give routine treatment and compare to novel treatment

Question 25

What is the placebo effect?

Answer 25

observed effect that is usually beneficial and attributable to the expectation that the regimen will have an effect

Question 26

What are the characteristics of the standard treatment group?

Answer 26

group that receives current market leader or the drug that has been available the longest

Question 27

What is blinding?

Answer 27

individuals involved in the study are kept unaware of the assigned intervention

Question 28

What are the types of blinding?

Answer 28

-single: patient/owner is blinded
-double: patient/owner and clinician are blinded
-triple: patient/owner, clinician, and data analyst are blinded

Question 29

What are the benefits of blinding?

Answer 29

-minimize observation bias
-improve patient compliance and retention
-reduce co-interventions

Question 30

What is intention-to-treat analysis?

Answer 30

-use every subject who was randomized according to treatment assignment
-ignore non-compliance, protocol deviations, withdrawal, and anything that happens after randomization

Question 31

Why is intention-to-treat analysis used?

Answer 31

-analysis based on compliant participants only can lead to a skewed positive response rate due to systematic bias and confounding effect
-ITT analysis reduces likelihood of systematic error

Question 32

What is a primary study?

Answer 32

study where the investigators enroll the study participants themselves and/or follow them throughout the study

Question 33

What is a secondary study?

Answer 33

study that synthesizes several primary studies with a goal of addressing a unique hypothesis

Question 34

What is a systematic review?

Answer 34

answers a defined research question by collecting and summarizing all empirical evidence from primary studies that fits pre-specified eligibility criteria

Question 35

What is a meta-analysis?

Answer 35

use of statistical methods to summarize the results of systematic reviews