Experimental Design Flashcards
what is a case report or case series?
A report on a single patient or a single treatment/intervention or small set of patients without any control groups
What is a Case-control study?
prevalence of exposure > in (cases) than (controls)
Study patients with a specific condition compared with people who do not have the condition; less reliable than randomized controlled trials. Both groups are expose to a factor
what are the pros of a Case-control study?
- Fairly easy and cost-effective
- Tend to support, but not prove causal hypotheses
1.
what are Observational Cohort studies?
Evaluate and follow patients who have a specific exposure or receive a particular treatment over time and compare them with another group that is similar but has not been affected by the exposure being studied
What are the pros of Observational Cohort studies?
Best method for determining the incidence and natural history of a condition
- Determine whether there is an association between a factor and development of disease
- Derive inferences appropriate regarding possible causal relationships
what means that a study is double blinded?
both the investigators and the subjects do not know whether they received an active medication or a placebo
what are Randomized controlled trials (RCTs)?
Subjects are randomly assigned to a treatment or a control group that received placebo or no treatment; only difference between the two groups is the intervention being studied.
Can be single or double blinded
what are the study phases?
Phase I
- Small N
- Toxic and pharmacologic effects
Phase II:
- Larger N
- Safety and efficacy studies
Phase III (RCT)
- Large scale randomized controlled trials
- Effectiveness and relative safety
- Often multicenter
- Certain side effects may not be evident for years
Phase IV
- Postmarketing surveillance
- Important for monitoring new agents as they come into general use by public
What are the pros of Randomized controlled trials (RCTs)?
-RCTs are the gold standard design to test therapeutic interventions
- Determine whether the intervention had a significant impact relative to the no-intervention
group. Best for: Determining cause-effect
- Studying definable treatments or exposures