lecture 5 Flashcards

1
Q

What is the 4 bottom hierarchy of evidence?

A

4- Cohort studies
5- Case- control studies
6- Cross -sectional studies
7-Case reports

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

What are the bottom four hierarchy evidence called?

A

Observational studies

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

Apart from observational studies what other studies is part of the hierarchy system ?

A

Experimental studies

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

What other name is given for experimental studies?

A

Clinical trials

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

What does a clinical trial consist of?

A

Treatment group and control group

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

What is the difference between experimental and observational studies?

A

Observational studies have confounding

Experimental studies have no confounding

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

What if there is no control group?

A

Dummy control

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

What is the importance of a control arm?

A

you have a control group

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

What alternative trial is there?

A

Cross over trial

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

What does a cross over trial consist?

A

Two experiment periods separated by ‘wash out’

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

What is the advantage of cross over trial?

A

Minimise variability

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

What is the disadvantage of a cross over trial?

A

Not suitable if effect carried over

  • if experiment A works then it will not proceed to experiment B it will just stop
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What types of clinical trials are there?

A

Phase 1 and phase 2

phase 3 and phase 4

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

What is phase 1 and phase 2 trails?

A

Safe trails that are carried out in animals as the agent is too toxic and not safe for humans

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

What is phase 3 trail?

A

Randomised treatment comparison- which sometimes can be used in random humans

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

What is phase 4 trail?

A

Post marketing surveillance which are tests carried out in humans - to know that a treatment works and want to know if it continues to work under different clinical regimes

17
Q

In cross over trials what must be the same in each arm?

A

Subject on each arm must be the same

18
Q

How do you make sure the subject on each arm are the same?

A
  • Randomisation: random allocation
  • Making them the same: reduce bias (volunteer bias)
  • single blind or masked trial: placebo effect
  • Assessor bias
  • Double blind trail
19
Q

What is volunteer bias?

A

Cannot select px- no volunteering in what treatment they get as it is random allocation - px is not ware of their treatment

20
Q

What is the placebo effect?

A

dummy treatment given to the px to fool them

21
Q

What is assessor bias?

A

Assesors can choose what treatment they want to give which px- assessors can often bias the results for other reasons

22
Q

What 5 different ethical issues are there in clinical trails?

A

Numerous
Research and ethics committees
Declaration of helsinki
Informed consent: px must just receive placebo
Sample size- (too small or too large can be unethical)

23
Q

What other issues are there?

A

> Non compliance ( intention to treat)
Publication bias (negatives finding not published)
Multi-centre trails (trails used in different hospitals)
Meta analysis- combining results from different trails- systemic reviews

24
Q

What is non compliance ( intention to treat)

A

If they do not get treated results used as if they are treated

25
Q

What is publication bias?

A

results that did not work does not get published, but now has to be published

26
Q

> What is multi centre trials?

A

collect data from different places ie hospitals

27
Q

What is meta analysis-?

A

Combining different results from different trails- researchers get results from different trails to get the answer for same study. this is the best type of research evidence?

28
Q

What type of research is the meta anaylses?

A

Secondary research

29
Q

What are the RCTs and meta analysis of RCT?

A

gold standard for evidence based medicine

30
Q

What gold standard for evidence based medicine trails are there

A

RCTs or meta analysis for RCT

31
Q

What is the 7 heirarachy of evidence?

A
1- Meta analysis for RCTs 
2-RCTs with positive findings 
3-RCTs with negative findings
4-Cohort studies
5-Case control studies 
6- Cross sectional studies 
7-case reports
32
Q

What is RCTs for negative findings?

A

When the treatment does not work

33
Q

if you follow up four study groups over a period of 20 years to identify the impact of regular small doses of the drug what study is this ?

A

observational cohort studies

34
Q

in a study austrialian research looked at past randomised trails comparing steriod injectios into the tendon placebo which is equivalent to no treatment at all what study is this

A

Experimental meta analysis

35
Q

the employees were asked to complete a questionnaire what study is this?

A

observational cross section