Interventional Study Designs Flashcards
What study designs are thought to be the only ones that can prove causation?
interventional studies
What are some other terms for interventional studies?
clinical trial, clinical study, experimental study, human study, investigational study
What is the key difference between interventional and observational studies?
In interventional, investigator selects interventions and allocates study subjects to forced-intervention groups. They are more “rigorous” in ability to demonstrate causation.
What is the pre-clinical phase of an interventional study?
study phase that does NOT involve humans; it may involve animals.
In general, the higher the phase, the higher the _____
population.
What is phase 1 of an interventional study?
phase in which healthy volunteers (20 - 80) are used to asses safety, dose, toxicity of a drug. It is a short duration.
What is phase 2 of an interventional study?
phase in which 100 - 300 patients with condition of interest are used to determine efficacy; safety is still important. It is short to medium in duration.
What is phase 3 of an interventional study?
Phase in which 1000 - 3000 patients with condition of interest are tested, with a PRIMARY purpose of efficacy. It also uses superiority, non-inferiority and equivalency formats.
What is another word for placebo?
Dummy
What is phase 4 of an interventional study?
Long term effects of a drug in a large population are assessed. The goal is maintain long-term safety. It may rely on registries and surveys and can also be considered an observational study.
What kind of study is phase 4 sometimes considered to be?
observational
What are the advantages of interventional trials?
they can show causation and they are the only studies used by the FDA.
What are the disadvantages of interventional trials?
cost, time, ethics, and most importantly external validity - are the conditions of the study applicable to the general population?
What is a feature of explanatory studies?
they are generally restrictive in the amount of dosages, etc. given to each patient. They do not have much flexibility.
What is a feature of pragmatic studies?
they are more flexible - drug combinations may be compared, placebos may not be used, and regulat people with multiple comorbidities are studied.
What is a simple interventional study?
A study in whcih patients are randomized only once. Patients are divided into two groups, and a single hypothesis is tested.
What is a factoral interventional study?
A study in which subjects are randomized at least twice; groups are divided into sub-groups. It is used to test multiple hypotheses at the same time.
What is a negative of a factorial study?
More participants are needed in order to answer more questions.
What are benefits of a factorial study?
Efficiency, sample size, complexity are improved, and the study is not as generizable.
What are parallel interventional studies?
Studies in which groups are randomized, and no switching of intervention groups occurs after that.