Phase I - 4
Phase I - 4
1. Conducted to generate preliminary PK/PD data
2. Conducted in healthy subjects when expected toxicity is minor or extremely ill patients if therapy is toxic
3. In severe diseases, the aim is to find the maximum tolerated dose
4. Typically single dose or only a few weeks of treatment
Phase II - 4
Phase II - 4
1. First time patients are exposed to drug
2. Small study of efficacy
3. Aim to find out more about PK/PD & common adverse reactions
4. Determine daily dosage & regimen to be tested more rigorously in phase III
Phase III – 3
Phase III – 3
1. Aim to give a definitive assessment of intervention’s toxicity & efficacy
2. Classified according to how the control is selected
3. Interventions can include new drugs, devices, trt methods e.g. surgical techniques
Double blind vs Single blind
Double blind vs Single blind
Double blind - Neither patient or physician/researcher knows the treatment being taken
Single blind - Patient or assessing physician does not know which treatment is being taken
Observational studies - 3
- Non-experimental: no risk to patients
- No control over exposures assigned but can select subjects included
- Confounding will occur
Hospital controls - 3
Hospital controls
1. Advantages : easy to recruit
Disadvantages :
2. might not come from the same population
3. might be more likely to have risk factors such as smoking / alcohol / poor diet than the general population
Community Controls - 3
Community Controls
1. Advantages: Might be more representative
Disadvantages:
2. Harder to recruit (less interest in study?)
3. More issues with recall bias?
Volunteer bias
Studies only include those who choose to participate
Cohort
- Take a group from the population who do not have the outcome of interest
- Follow them forward in time and see what happens.
- Exposure is known
- Compare outcomes in exposed and unexposed people in the cohort
- Calculate risk ratio
Case-Control
- Take a group with the outcome of interest (cases)
- Retrospectively identify an appropriate comparison group
- Compare exposures in cases and controls
- Calculate odds ratio
Teratology Information Services (TIS)
Place of contact for woman regarding utero exposures to drugs
Pregnancy prevention plans
Pregnancy prevention plans used for women who are using highly teratogenic products to ensure they are not pregnant
