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Epidemiology - Heckert > Lecture #7-9 - Interventional Studies > Flashcards

Lecture #7-9 - Interventional Studies Flashcards

1
Q

Definition: All individuals making up a common group; from which a
sample (smaller set) can be obtained, if desired

A

Population

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2
Q

Definition:A subset or portion of the full, complete population

(“representatives”)

A

Sample

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3
Q

Null Hypothesis (H0)

A

o A researcher‐perspective which states there is no (true)
difference between the groups being compared
Most conservative and commonly utilized

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4
Q

Alternative Hypothesis (H1)

A

Opposite of the Null Hypothesis – A study hypothesis
(researcher‐perspective) which states there is a (true)
difference between the groups being compared

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5
Q

In interventional studies are exposures assigned or not assigned?

A

assigned

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6
Q

The following terms all are another name for:

Clinical Trial, Clinical Study,
Experimental Study, Human Study, Investigational
Study

A

Interventional Study

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7
Q

What is the key difference between observational studies and interventional studies?

A

In interventional studies the investigator selects interventions and allocates study subjects to forced intervention groups.

Interventional can show causation, observational cannot

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8
Q

The following describes which state of Interventional Studies:

prior‐to human investigation

A

Pre-clinical

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9
Q

The following describes which stage of interventional studies:

Small N (~20‐80), healthy volunteers, used for the first time in
humans to assess safety, toxicity and pharmacokinetics

SHORT DURATION

A

Phase 1

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10
Q

The following describes which stage of Interventional Studies:

Larger N (~100‐300), commonly utilize patients with condition
of interest, used to expand on purpose of the earlier phase
(safety) but also to begin assessing efficacy in diseased
population

A

Phase 2

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11
Q

Which stage is likely to have a narrower inclusion criteria?

Phase 1 or Phase 2

A

Phase 2

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12
Q

The following describes which stage of Interventional Studies:

Even Larger N (~1,000‐3,000), used in patients with condition
of interest to continue determination of safety, with primary
purpose to assess efficacy

Long duration (months to years)

A

Phase 3

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13
Q

The following describes which stage of Interventional Study:

Long‐term effects (risks & benefits) in a large population of
diseased patients (expanded use population (age, ethnic))

Post-marketing

A

Phase 4

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14
Q

What are the disadvantages of Interventional Trials (state 2 - there are 4)

A

o Cost
o Complexity/Time (development/approval/conductance)
o Ethical considerations (Risk vs. Benefit evaluation)
o Generalizability (a.k.a.; External Validity) – Is study
population similar to general population and will
methodology and findings be applicable to them?

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15
Q

Which design of interventional studies divides groups into 2 or more groups and includes only one randomization process. This is typically used to test a single hypothesis.

A

Simple

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16
Q

Which design of interventional studies divides the subjects into two or more groups AND ALSO additionaly subdivides each of the groups into two or more groups

A

Factorial

(3x3x2 etc)

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17
Q

What are the properties of a Factorial type design?

A
  • Improves efficiency for answering clinical questions
  • Increases study population sample size (due to increased group #)
  • Increases complexity (which may be a barrier to recruitment)
  • Increases risk of drop outs (due to complexity), and
  • May restrict generalizability of results
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18
Q

What type of study design has groups simultaneously and exclusively managed
with no switching of intervention groups after initial randomization

A

Parallel

• All Simple and Factorial study designs are also Parallel

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19
Q

What type of study design has Groups serve as their own control by crossing over from one intervention to another during the study

A

Cross-over (aka Self-control)

  • Allows for smaller total “N” (sample size)
  • Each patient contributes additional data
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20
Q

What are TWO disadvantages of cross-over design?

A

o Only suitable for long‐term conditions which are not curable for which treatment provides short‐term relief
o Duration of study for each subject is longer
o Carry‐over effects during cross‐over (wash‐out required; which prolongs study duration)
o Treatment‐by‐Period interaction- Differences in effects of treatments during different time periods
o Smaller N requirement only applicable if within‐ subjects variation less than between‐subjects variation
o Complexity in data analysis

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21
Q

What is the difference between a “wash-out” and “lead-in” phase?

A

lead in is before the trial. Wash-out is in the middle and normally as one group is crossing over to test a different variable.

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22
Q

Define the following referring to Outcomes/Endpoints:

  • Primary
  • Secondary / Tertiary / etc…
  • Composite
A

o Primary- Most important, key outcome(s)
• Main research question (hypothesis) used for developing/conducting
study

o Secondary / Tertiary / etc…
Lesser importance yet still valuable
Possible for future hypothesis generation

o Composite - Combines multiple endpoints into a single outcome

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23
Q

The following are examples of what kind of Endpoints?

 Death
 Stroke or Myocardial infarction
 Hospitalization
 Preventing need for dialysis

A

Direct Endpoints

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24
Q

What would you describe the following as (elemends used in palce of evaluating direct endpoints)

 Blood pressure (for risk of stroke)
 Cholesterol (for risk of heart attack)
 Change in SCr (for worsening renal function)

A

Surrogate Markers

25
Q

Define Non-random group allocation:

A

Subjects don’t have an equal probability of being selected or
assigned to each intervention group (e.g., Convenience
Sampling/Non‐probabilistic allocation)

example: first 100 patients admitted to a hospital

26
Q

Define Random group allocation:

A

Subjects do have an equal probability of being assigned to each intervention group

27
Q

What is the purpose of randomization?

Where would you find information on randomization in a paper?

Is equality guaranteed?

A

to make groups as equal as possible; based on
known and unknown important factors (confounders)

Table 1

No

28
Q

Which form of randomization Ensures balance within each intervention group to ensure all groups are equal in size

A

Blocked

29
Q

Which form of randomization Ensures balance with known confounding variables like age, gender, disease severity?

A

Stratified

30
Q

The following refers to what type of masking?

Study subjects are not informed which intervention they are
receiving (but clinicians/researchers are!)

A

Single‐Blind

31
Q

The following refers to what type of masking?

Neither investigators nor study subjects are informed which
intervention each subject is receiving

A

Double‐Blind

32
Q

The following refer to what type of masking?

Everyone knows which intervention each subject is receiving

A

Open‐Label

33
Q

How could you assess the adequacy of blinding?

A

post-hoc surveys

34
Q

Placebo (“Dummy” therapy) refers to:

A

Inert treatments made to look identical in all aspects to the active
treatments

Double‐Dummy – more than 1 placebo used

35
Q

What is the Placebo effect?

A

Improvement in condition; by power of suggestion & due to the
care being provided

Can be as large as 30‐50%!

36
Q

What is the Hawthorne‐effect

A 
Desire of study subject to “please” investigators by reporting
positive results (improvement), regardless of treatment allocation
37
Q

Discuss:

o Inclusion/Exclusion criteria (interventional studies) & Case‐
and Exposure‐defined (observational studies)

 Desired vs. Logical vs. Plausible

 These absolutely impact generalizability!

• External Validity

A
38
Q

Define: Autonomy

A

Self‐rule/Self‐determination. Participants must…
• Have full & complete understanding of the risks and benefits

  • No misinformation, incomplete information, or ineffectively‐conveyed information (language or education level)
  • Decide for ones‐self, without outside influences
  • No coercion, reprisal, financial manipulation
39
Q

Define: Beneficence

A

To benefit, or do good for, the patient (not society)

40
Q

Define Justice in regards to bioethics

A

Equal & Fair treatment regardless of patient characteristics

41
Q

Define Nonmaleficence with regard to Bioethics

A

 Do no harm. Researchers must not…
• Withhold information
• Provide false information
• Exhibit professional incompetence

42
Q

What is the difference between consent and assent?

A

Consent:Agreement to participate, based on being fully and
completely informed [given by mentally‐capable individuals
of legal consenting age (i.e., adults; age 18 in most states)]

(FOR CHILDREN) Assent: Agreement to participate, based on being fully and
completely informed, given by mentally‐capable individuals
not able to give legal consent (i.e., children and adolescents)

43
Q

1978; issued by National Commission for Protection of
Human Subjects of Biomedical and Behavioral Research

A

Belmont Report

The Belmont Report attempts to summarize the basic ethical principles identified by the Commission in the course of its deliberations.

44
Q

What is the role of the IRB? What type of studies MUST be reviewed?

A

to protect human subjects from undue risk (not
complying with principles of bioethics)

All human subject studies MUST be reviewed by an IRB prior
to study initiation

45
Q

Define:

Equipoise

A

genuine confidence that an intervention
may be worthwhile (risk vs. benefit) in order to use it in
humans

46
Q

What officer enforces the regulations of the IRB?

What officers develops regulations for the IRB?

A

Office of Human Research Protections (OHRP)

Department of Healthand Human Services (DHHS)

47
Q

Which level of IRB:

– used for ALL interventional trials with
more than minimal/no risk to patients
 All medication‐related studies

A

Full Board

48
Q

Which level of IRB:

has minimal risk and no patient identifiers

A

Expedited

49
Q

Which level of IRB:

has no patient identifiers, low/no risk, de‐
identified dataset analysis, environmental studies, use
of existing data/specimens (de‐identified)

A

Exempt

50
Q

Do studies that qualify for exempt level of IRB have to be submitted at all?

A

YES

51
Q

WHO gets to decide level of review?

A

The IRB

52
Q

What does the Data Safety & Monitoring Board (DSMB) do?

A

Semi‐Independent committee not involved with the conduct
of the study but charged with reviewing study data as study
progresses, to assess for undue risk or benefit

53
Q

When managing drop outs/ LTFs:

Intent‐to‐Treat (most conservative decision) involves..

A

• Last known assessment (observation) used for (carried forward)
all subsequent, yet missed assessments (LOCF)

• Convert all subsequent yet missed assessments for a subject to a
null‐effect (no benefit)

54
Q

Intent‐to‐Treat results in what?

A

 Preserves randomization process
 Preserves baseline characteristics and group balance at
baseline which controls for known and unknown confounders
 Maintains statistical power (original sample size)

55
Q

If a patient wants to / have to switch groups, this would be defined as:

A

o Treating them “as treated”

• Ignores group assignments;
• Allows subjects to switch groups and be evaluated in group they
moved to, end in, or stay in most

56
Q

The third option other than as treated and intent-to-treat would be:

A

to ignore themm (include only compliant or completing
subjects)

57
Q

What are ways you could assess adherence (compliance)?

A

o Drug levels (multiple useful sites)
o Pill counts at each visit
o Bottle counter‐tops

58
Q

What are some ways you could improve adherence (compliance)?

A

o Frequent follow‐up visits/Communications
o Treatment alarms/notifications
o Medication blister packs or dosage containers

59
Q

CHEST GUIDELINES? Do we need to know?

A

Epidemiology - Heckert (7 decks)

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