Clinical trials

Question 1

Name 4 different trials

Answer 1

Double blind
Single blind
Prospective
Retrospective

Question 2

Double blind

Answer 2

Doctor nor patient know if active or placebo drug is given to the patient, kept secret to the end of the trial

Question 3

Single blind

Answer 3

Patient doesn’t know but doctor does id the patient is give the active or the placebo drug

Question 4

What is the purpose of pilot studies

Answer 4

Not to estimate outcome but to study pilot design

Question 5

Prospective

Answer 5

design study, recruit patient and follow them up = study over time

Question 6

Reterospecive

Answer 6

Not the data you have collected for the trial but compare other data from previous medical history

Question 7

Placebo contolled study

Answer 7

half patents are given active drug while the other half receive placebo - comparisons made between similar patients who differ in certain characteristics

Question 8

Cross over design

Answer 8

Half study drug other compared therapy
Wash out period
swap over treatment and see if treatment is better

Question 9

Disadvantages of randomised control clinical trials

Answer 9

Subjects may not represent general patients
Tend to be better at complying
Recruitment = need twice as many patients
Some patients or physicians will refuse to randomise
Administrative complexity

Question 10

Designing a study

Answer 10

Clear hypothesis 
Should have an End point
Randomised double blind comparison 
Number of subjects - need enough to be able to detect or reject 
Decide your placebo "control drug"

Question 11

What is the choice of patients dependant on

Answer 11

age
sex
race
any concurrent diseases + medication or drugs /
will they comply or continue to follow instructions

Question 12

What kind of people may need to be excluded from studies

Answer 12

pregnant 
children 
seriously ill
elderly 
side-effect risk patients

Question 13

What are the features of Ethics with clinical trials

Answer 13

consent 
ehtics comittee 
decide on placebo 
Children 
Study designs 
Policing studies 
Make sure you have insurance 
follow the law

Question 14

Why are clinical trial necessary

Answer 14

provide evidence (medical practise = evidence based; need to critically evaluate evidence)
what works in theory might not be best in practise
test efficacy compared with placebo / another drug /
test safety = protect public
provide evidence to help rational prescribing
help inform doctors treating patients appropriately

Question 15

What do clinical trials provide

Answer 15

evidence

Question 16

What is phase one clinical studies

Answer 16

volunteer studies = some given active drug whilst some given placebo; usually paid + regulated environment

Question 17

What is phase two clinical studies

Answer 17

patient studies = involves a fixed number of patients to investigate kinetics / dynamics in patients

Question 18

what is phase three clinical studies

Answer 18

formal therapeutic trials = evidence of safety obtained; involves much larger group of patients; data compiled + submitted as an application to a regulatory authority for a licence to sell the drug

Question 19

what is phase four clinical studies

Answer 19

post-marketing surveillance of drug to ensure long term safety = involves thousands of patients
MHRA = medicines + healthcare devices regulatory authority (committee on safety of medicines); uses yellow card system = GPs / hospital doctors / pharmacists

Question 20

what is phase five clinical studies

Answer 20

drug in widespread clinical use = relative comparisons (is X > Y / Z); exploration of new uses for the drug

Question 21

what is the placebo effect

Answer 21

patient makes an improvement

Question 22

what does p=0.05 mean

Answer 22

p-value less than 0.05 leads us to conclude that there is evidence against the hypothesis