Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Clinical Pharmacology & Intro to Prescribing > Session 1: Clinical Trials > Flashcards

Session 1: Clinical Trials Flashcards

1
Q

Definition of a clinical trial.

A

Any form of planned experiment which involves patients and is designed to elucidate the most appropriate method of treatment for future patients with a given medical condition.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the purpose of a clinical trial?

A

To provide reliable evidence of treatment efficacy and safety.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Define efficacy.

A

The ability of a health care intervention to improve the health of a defined group under specific conditions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Define safety

A

The ability of a health care intervention not to harm a defined group under specific conditions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

In order to be able to give a fair comparison of effect and safety, what does a clinical trial need to be?

A

Reproducible

Controlled (comparison of interventions)

Fair (unbiased)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are clinical trial vulnerable to?

A

Random variation (chance)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How is chance reduced?

A

By increasing sample size

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the difference between efficacy and effectiveness?

A

Efficacy = ideal clinical conditions (sterile)

Effectiveness = real world clinical experience (reality)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Give the different stages in drug development.

A

Pre-clinical phase with animals

Phase 1 with volunteers

Phase 2 is a treatment study with patients (effects and dosages as well as side effects)

Phase 3 is the clinical trial with patients (comparison with standard treatments)

Phase 4 is to whole population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Explain the disadvantages of non-randomised clinical trials.

A

Allocation bias by patient, clinician or investigators

Confounding factors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Explain the disadvantages of comparison with historical controls.

A

Selection is often less well defined and less rigorous

Treated differently from new treatment group

Less information about confounders and potential bias

Unable to control for confounders

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Explain the steps in a RCT conducting the trial.

A

Eligible patients

Invite patients

Consent

Allocate treatment fairly (no bias, no confounding)

Follow-up (also minimise losses)

Maximise adherence to treatments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Reasons for Pre-defining outcomes

A

Need to define what, when and how outcomes are to be measured before start of the clinical trial.

This is to prevent data dredging and repeated analyses.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are primary outcomes?

A

Preferably only one primary outcome of your desired effect.

This is used in the sample size calculation.

E.g. mortality

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are secondary outcomes?

A

Other outcomes of interest that may appear in the clinical trial.

They often include occurrence of side-effects.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Give examples of types of outcomes.

A

Patho-physiological (tumour, thyroxine levels, ECG changes)

Clinical defined (death, disease, disability)

Patient-focused (quality of life, psychological well-being, social well-being, satisfaction)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Give examples of an ideal outcome.

A

Appropriate and relevant

Valid and attributable

Sensitive + specific

Reliable and robust

Simple and sustainable

Cheap and timely

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Why is the timing of measurement important?

A

Using a baseline in order to monitor inadvertent differences in groups.

Monitor the possible effects as well as monitoring for adverse effects.

Final measurements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the issues with non-random allocation?

A

Selection bias

Confounding factors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the advantages of random allocation?

A

Minimal allocation bias

Minimal confounding factors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Issues with knowing the treatment allocation.

A

May bias the results of the clinical trial by:

Behaviour effect (patient may alter their behaviour)

Non-treatment effect (clinician might alter their interest in the patient depending on treatment of the patient)

Measurement bias (investigators)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Give an example of minimising allocation bias.

A

Blinding/masking

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Give examples of blinding.

A

Single blind (patient doesn’t know treatment allocation)

Double blind (patient + clinician/assessor don’t know treatment allocation)

Triple blind (usually synonymous with double blind)

24
Q

Examples where blinding is difficult.

A

Surgical procedures

Psychotherapy

Alternative medicine

Lifestyle interventions

Prevention programmes

25
Q

Advantages of blinding

A

Reducing selection bias

Reducing recall or reporting bias

Reducing observer bias

26
Q

Explain the placebo effect

A

Even if therapy is irrelevant to the patient’s condition, the patient’s attitude to his or her illness and indeed the illness itself, may be improved by a feeling that something is being done about it.

27
Q

What is a placebo?

A

An inert substance made to appear identical in every way to the active formulation with which it is compared to.

28
Q

What is the aim of a placebo?

A

To cancel out any placebo effect that may exist in the active treatment.

29
Q

Ethical implications of placebo.

A

A placebo should only be used when no standard treatment is available.

Use of a placebo is a form of deception.

Important to inform the participants that they may receive a placebo.

30
Q

Give different losses to follow-up.

A

Appropriate loss of follow up (clinical condition may necessitate removal from trial)

Unfortunate loss of follow up (patient may choose to withdraw)

31
Q

How to minimise losses to follow up.

A

Make follow-up practical and convenient

Be honest about commitment required

Avoid coercion or inducements

Maintain contact

32
Q

Give examples of non-compliance

A

Misunderstanding of instructions

Not like treatment

Treatment not working

Prefer to take another treatment

Can’t be bothered

Forget

33
Q

How to maximise compliance with treatments

A

Simplify instructions

Ask about compliance

Ask about effects and side-effects

Monitor compliance and remind, etc…

34
Q

Give two interpretations of ‘Is the new treatment better than the standard treatment?’.

A

Is physiological action of new treatment better than standard treatment?

Is the new treatment better than the standard treatment in routine clinical practice?

35
Q

Explain the Explanatory Trial: As-treated analysis.

A

Analyses only those who completed the follow-up and complied with treatments.

Compares physiological effects of the treatments.

36
Q

Disadvantages of Explanatory Trial: As-treated analysis.

A

Loses effects of randomisation where non-compliers are likely to be systematically different from compliers leading to selection bias and confounding.

37
Q

Explain pragmatic trail: Intention-to-treat analysis.

A

Analyses accodring to the original allocation to treatment groups regardless of follow-up or compliance.

Compares the likely effects of using the treatments in routine clinical practice

This means that it preserves the effects of randomisation.

38
Q

Differences between As-treated and Intention-To-Treat analyses.

A

As-Treated analyses tend to give larger sizes of effect.

Intention-To-Treat analyses tend to give smaller and more realistic sizes of effect.

This means that clinical trials should normally be intention-to-treat.

39
Q

Give examples of what is important to think of in order to get a good RCT.

A

Randomisation

Blinding

Intention-to-treat

40
Q

What is collective ethic?

A

All patients should have treatments that are properly tested for efficacy and safety.

41
Q

What is individual ethic?

A

Principle of beneficence (Will my clinical trial benefit patients?)

Priniciple of non-maleficence (Will my clinical trials hurt anyone?)

Principle of autonomy (Can I guarantee patient choice?)

Priniciple of justice (Is my clinical trial just?)

42
Q

Explain individual ethics concerning RCTs.

A

RCTs may not guarantee benefit

RCTs may result in harm

RCTs may allocate treatment by chance

RCTs may place burdens and confer benefits

43
Q

Explain clinical equipoise.

A

When there is reasonable uncertainty or genuine ignorance about the better treatment or intervention.

44
Q

Issues with clinical equipoise.

A

Is the uncertainty or ignorance by the individual clinician or the scientific community as a whole?

What constitutes reasonable uncertainty?

How is ‘better’ defined for the individual patient or for society as a whole?

45
Q

Explain why an RCT should be scientifically robust.

A

Adress a relevant or important issue

Ask a valid question

Can justify use of the comparator treatment or placebo

46
Q

Explain issues with ethical recruitment of inclusion.

A

Participants from communities that are unlikely to benefit. E.g. AIDS drug trials in developing world countries.

Participants with a high risk of harm with respect to potential benefits. E.g. pregnant women.

Participants likely to be excluded from analysis. E.g. a small sub-group of Chinese

47
Q

Explain issues with ethical recruitment of inapproriate exclusion.

A

People who differ from an ideal homogenous group. E.g. non-white, women, co-morbidities

People who are difficult to get valid consent from. E.g. immigrants, mentally ill, children, prisoners

48
Q

What does valid consent consist of?

A

Knowledgeable informant

Appropriate information - verbal and written consent, a cooling off period, freedom to opt out

An informed participant, competent decision maker and a legitimate authoriser.

49
Q

Is signed consent valid consent?

A

Signed consent form as evidence of valid consent but it does not equate to valid consent.

50
Q

Explain voluntariness.

A

A pre-requisite for consent to be valid.

The decision should be free from coercion or manipulation or the perception that coercion or manipulation may take place.

Perceived coercion or manipulation invalidates consent as much as actual coercion or manipulation.

51
Q

Give examples of coercion.

A

Non-access to best treatment

Lower quality of care

Disinterest by clinician

52
Q

Give examples of manipulation.

A

Exploitation of emotional state

Distortion of information

Financial inducements

53
Q

Give another issue of voluntariness.

A

If undue influence is being exerted causing the potential participant to act in an uncharacteristical way then that influence is regarded as unethical.

54
Q

What do research ethics committees focus on?

A

Scientific design and conduct of the study

Recruitment of participants

Care and protection of participants

Protection of participant’s confidentiality

Informed consent process

Community considerations

55
Q
A

Clinical Pharmacology & Intro to Prescribing (24 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions