epidemiological studies (RCT)

Question 1

what is a clinical trial ?

Answer 1

it is a prospective study comparing the effect of an intervention against a placebo or conventional treatment in human beings

Question 2

what is a single armed clinical trial ?

Answer 2

means that everyone enrolled in the clinical trial will be treated the same way

Question 3

what is a cross-over design ?

Answer 3

each subject receives all the products in phases , each phase is separated by a wash out period

Question 4

what are selection of subjects based upon ?

Answer 4

exclusion and inclusion criteria

unlike with case control participants are chosen using eligibility criteria and diagnostic criteria

Question 5

what are some ethical considerations when selecting subjects for RCT ?

Answer 5

involvement of children

Question 6

what is the purpose of randomization ?

Answer 6

to ensure that neither investigator nor patient decides the treatment to be assigned
balances the known and the unknown factors
a method to deal with the confounding factors

randomization is the method of choice used to get rid of confounding factors in RCT

Question 7

what is allocation concealment ?

Answer 7

critical to prevent selection bias , ensures that the patients dont know their allocation

Question 8

what are the two important methods for removing bias in clinical trials ?

Answer 8

randomization

blinding

Question 9

what are the levels of blinding ?

Answer 9

individual
investigators
analysts

Question 10

in what type of studies may blinding of treatment be difficult ?

Answer 10

surgical vs medical treatment

non-pharmacological and behavioural interventions

Question 11

what is placebo ?

Answer 11

ann inert compound given to subjects in a clinical trial

Question 12

when is using placebo arms unethical ?

Answer 12

when there is an established intervention

Question 13

what are the types of RCT endpoints ?

Answer 13

primary endpoints
surrogate endpoints
composite endpoints
safety outcomes

Question 14

what is a primary endpoint ?

Answer 14

main measurement for a trial

Question 15

what is a surrogate endpoint ?

Answer 15

biomarker intended for the substitution of a clinical endpoint
reflects how a patient feels

Question 16

what are composite endpoints ?

Answer 16

where the intervention is considered a success or a failure

Question 17

what is meant by safety outcomes in RCT ?

Answer 17

rate of adverse events

Question 18

which documentation should be considered for ethical purposes when wanting to perform a clinical trial ?

Answer 18

helsinki declaration

Question 19

when should a trial be stopped ?

Answer 19

1. if severe or unexpected side effects or complications occur
2. if the benefit from the intervention becomes evident and undeniable

Question 20

how is monitoring of the events in an RCT achieved ?

Answer 20

through interim analyses, sample size must be adjusted for the number of interim analyses
abl ma nelem el wara2 interim analysis is made

Question 21

which committee is responsible for data throughout the duration of the study ?

Answer 21

data and safety monitoring board ( DSMB)

Question 22

what is the difference between :
intent to treat analysis
and
per protocol analysis ?

Answer 22

1. ITT: involves all participants that are enrolled in the trial regardless if they completed it or not
2. per protocol analysis: includes only those who completed the trial

Question 23

how is efficacy calculated ?

Answer 23

incidence in placebo - incidence in treatment
____________________________________
incidence in placebo

Question 24

how do you calculate number needed to treat?

Answer 24

1
______________
incidence in control - incidence treated