Population Study

Question 1

What is confidence interval?

Answer 1

→‘estimates’ or ‘means of something of interest’ is defined by the 95%
confidence interval

Question 2

What does a narrow confidence interval mean?

Answer 2

→ precise estimate

Question 3

What is 95% reference range?

Answer 3

→A measure of the spread of the continuous numerical data only

Question 4

What is 95% confidence interval?

Answer 4

→A measure of the precision of a sample estimate (95% probability
that interval contains the true population value for any parameter of
interest)

Question 5

What is the formula for reference range?

Answer 5

→Mean +/- 2 Standard Deviations

Question 6

What is the formula of confidence interval?

Answer 6

→Mean +/- 2 Standard Errors

Question 7

What are the phases of clinical trials?

Answer 7

→Preclinical
→Phase 1- 20-80, safety study
→Phase 2 100-300, side effects and effectiveness
→Phase 3 1000-3000 people
→Phase 4- long term side effects

Question 8

What are the objectives of Phase 1 study?

Answer 8

→To assess a safe & tolerated dose

2. To see if pharmacokinetics differ much from animal
   to man
3. To detect any predictable toxicity

Question 9

What demographic is excluded from Phase 1 studies?

Answer 9

→women of child bearing age

→children

Question 10

What is the inclusion criteria for Phase 1 study?

Answer 10

→Uniformity of subjects: age, sex,

nutritional status

Question 11

Which group of people are involved in Phase 2 drugs?

Answer 11

→20 – 200 patients with relevant disease

Question 12

What are the objectives of Phase 2?

Answer 12

→Therapeutic benefits & ADRs evaluated

→Establish a dose range to be used in late phase

→Single blind [Only patient knows] comparison with standard drug

→6 months to 2 years [ 35% success rate]

Question 13

Who performs Phase 3?

Answer 13

→Clinicians in the hospital

Question 14

What is the target population in Phase 3?

Answer 14

→250 – 1000 patients

Question 15

What are the objectives of Phase 3?

Answer 15

→Vigilant recording of all adverse drug reactions

→ Rigorous statistical evaluation of all clinical data

→up to 5 years [25% success]

Question 16

Describe Phase 4

Answer 16

→No fixed duration / patient population

→Starts immediately after marketing

→Report all Adverse reactions

Question 17

What are the objectives of Phase 4?

Answer 17

→rare ADRs

→ Drug interactions

→Also new uses for drugs

Question 18

Who are the participating parties in clinical trials?

Answer 18

→Patient / Healthy volunteer

→Clinical Pharmacologist, Clinical
Investigator & team: [Qualified and
competent]

→ Institution where trials are held :
[Approval required]

→Research Ethics Committee (REC) or
Institutional Ethical Committee

→Sponsor

→Regulatory Authorities:

Question 19

What are the roles of the Sponsor in clinical trials?

Answer 19

→Pays for all expenses;
→ Appoints competent investigators,
→Ships all drugs for the trial,
→ Files all papers to legal / regulatory authorities,

Question 20

Describe cohort studies

Answer 20

→A group of subjects followed over time

→Purpose: defining the incidence and investigating potential causes of a
condition (incidence)

→Can be prospective – investigator chooses a sample group and measures
characteristics in each subject over a period of time that might predict
outcomes

→Can be retrospective – same as prospective, except all data collection and
follow-up has happened in the past; only possible if adequate data is
available

Question 21

What are the strengths of experimental studies?

Answer 21

→Can demonstrate causality

Question 22

What are the types of interventions?

Answer 22

→behavioural
→drug
→device

Question 23

Compare parallel and crossover designs

Answer 23

→Parallel: simple treatment versus placebo

→Crossover: Comparison of treatment and placebo made in each subject

→Allows each subject to be a control such that treatments can be assessed in each subject (advantage)

→Period effects, carry-over effects, sequence effects all need to be considered (disadvantage)

→Longer duration and more complex stats (disadvantage)

→Smaller study sample required for power (advantage)

Question 24

Describe the timeline of a trial

Answer 24

→• 1) recruitment (adverts)
• 2)Screening (inclusion/exclusion criteria)
• 3) Informed Consent after patient information sheet
• 4)Randomisation/blinding
• 5) Protocol visits step by step procedures (deviations have to be communicated to sponsor and ethics research committee)
• 6) Reports of adverse events
• 7) Store investigatory product
• 8)Subject compensation
• 9) Electronic data collection
• 10) Study closure

Question 25

Describe informed consent

Answer 25

→Voluntary
• Explained in simple nontechnical language
• Translated in the native language of the subject
• Comprehensive information regarding the trials
• Benefit of new therapy over existing ones
• Alternative treatments available
• All possible adverse reactions
• Freedom to withdraw from the trial

Question 26

What is a confounder?

Answer 26

→Associated with the exposure of interest

→Independently associated with the risk of developing the outcome

Question 27

What can confounding lead to?

Answer 27

→under- or over-estimation of a real association between Exposure and Outcome

→Produce a spurious positive or negative association between Exposure and Outcome

Question 28

What can be calculated from the results of a cohort study?

Answer 28

→Risk ratio or relative risk (RR)

Question 29

What can be interpreted in RR>1?

Answer 29

→increased risk in exposed group compared to unexposed group