Experimental study

Question 1

Introduction

Answer 1

Research hypothesis: Relationship between independent & dependent/responding variable

Observational/Non-interventional studies:

Descriptive observational study has no comparison group

Analytical observational study has to have comparison group & research hypothesis, which requires scientific evidence

Question 2

Epidemiologic Study

Answer 2

Question 3

Experimental study

Answer 3

Definition:

A study of which the researcher is the one who controls OR assigns the situation of the study directly

Question 4

Types of experimental study

Answer 4

3 Types of experimental studies:

1. )Laboratory experiment
2. )Animal experiment
3. )Human experiment

Question 5

1.)Laboratory experiment

Answer 5

1. )Laboratory experiment:
   - Physical, chemical properties & analysis of drugs etc
   - Find out sub-therapeutic therapeutic and lethal dose of any drug & associated allergies
   - Plasma half-lives of drugs

Question 6

2.)Animal experiment

Answer 6

2. )Animal experiment:
   - Experimentation reproduction of human disese to confirm etiology
   - Testing the efficacy of preventive & therapeutic measures
   - Completing the natural history of disease

Question 7

3.)Human experiment

Answer 7

3. )Human experiment
   - To confirm an etiological hypothesis in testing the cause effect relationship
   - To evaluate OR assess the effectiveness of therapeutic OR preventive measure before applying them to the community

Question 8

The first clinical trial

Answer 8

The first clinical trial is by:

James F Lind 1716-1794

Vitamin C & Scurvy [1747]

Question 9

Vitamin C & Scurvy [1747]

Answer 9

Details regarding the 1st clinical trial:

• There were a total of 12 patients that took part in the study
• Each 2 patients were provided with 6 different types of remedies to cure scurvy, such as:
  1. )Cider
  2. )Vinegar
  3. )Oranges & Lemon
  4. )Seawater
  5. )Nutmeg
  6. )Elixir & Vitriol
• After 2 weeks, there were no improvements with other different cures, except for those patients who were treated with oranges & lemon, recovered in 6 days time

Question 10

Experimental study

Answer 10

3 Principle features of experimental study:

1. )Prospective study [Assigned intervention-by investigator]
2. )Control group
3. )Randomization

Question 11

Experimental study

Answer 11

Unethical to perform experiments on people if assigned exposure is harmful

Investigator intervenes the study group by deliberate application OR withdrawal of the suspected cause

Control group -> no intervention

Question 12

Subtypes/Subdivisions of experimental study

Answer 12

3 Subtypes/Subdivisions of experimental study:

1. )Clinical trial [Randomized controlled trials-RCT]
2. )Field trial
3. )Community intervention trial

Question 13

1.)Clinical trial [Randomized controlled trials-RCT]

Answer 13

Interventions are assigned to the patients

Question 14

2.)Field trial

Answer 14

Interventions are assigned to individual community member

Question 15

3.)Community intervention trial

Answer 15

Interventions are assigned to the whole communities

Question 16

1.)Clinical trial [Randomized controlled trials-RCT]

Answer 16

Interventions are assigned to the patients only

Example:

The study of the efficacy of short course Antiretroviral(AZT) treatment for the prevention of mother-to-child(vertical) transmission of HIV-1

Question 17

Phases of clinical trials [Randomized controlled trials-RCT]

Answer 17

4 Phases of clinical trials [Randomized controlled trials-RCT]

Phase 1: Safety & Pharmacologic studies

[Pharmacologic studies: Pharmacodynamic & Pharmacokinetic of drugs]

Phase 2 : Pilot efficacy studies

[Whether the study is feasible or not?]

Phase 3 : Extensive clinical OR field trials

[Whether done extensively OR not?]

Phase 4 : Post-marketing surveillance

[Whether safe OR not to consume? Eg: Captopril is withdrawn from the market as it causes dry cough, so enalapril is used instead]

Question 18

Phase 1 of clinical trial [Randomized controlled trials-RCT] :

Safety & Pharmacologic studies

Answer 18

1. )First introduction of a candidate vaccine OR drug into human population
2. )Study safety(pharmacovigilance) & pharmacologic profiles [pharmacodynamics-what drug does to the body? ; pharmacokinetic-what does body does to the drug?]
3. )Involve fewer than 100(20-80) volunteers

Question 19

Phase 2 of clinical trial [Randomized controlled trials-RCT] :

Pilot efficacy studies

Answer 19

1. )Focus on immunogenicity(with vaccine), safety & efficacy in comparison to other existing regimen(with drug)
2. )Involves 200-500 volunteers
3. )Usually, but not always, subjects are randomly allocated to study & control group

Question 20

Phase 3 of clinical trial [Randomized controlled trials-RCT] :

Extensive clinical OR field trials

Answer 20

1. )Complete assessment of safety, efficacy & effectiveness
2. )Involve thousands of volunteers
3. )Usually with random allocation to study & control groups
4. )Maybe a “Multi-center trial”

Question 21

Phase 4 of clinical trial [Randomized controlled trials-RCT] :

Post-marketing surveillance

Answer 21

1. )
2. )