Week 8 Flashcards
What are the two subcategories of experimental studies
Unplanned
Planned
What is an unplanned experimental study
Natural experiments
What is a planned experimental study
Cluster or community trials
Randomized trials
What is the defining feature of an experimental study
The investigator Assign exposure
Who conducted the first randomized clinical trial
Jame lind
What did Eward Jenner do
He did an experimental study with cowpox
What are some examples of ethical issues with experimental studies
The monster study (speech therapy)
What are the different groups in experimental studies
There is a treatment group from the source population
There is a comparison group
Over time you compare the incidence of outcome in treatment and comparison groups
Whats the difference between research questions for experimental vs observational studies
Experimental studies- involve prevention or treatment
It is feasible and ethical ( small population level effect expected)
Observational studies- prevention treatment and causal factor
And experimental study is not ethical or logical
Moderate large population level effect expe
What is prevention trial
Prevention trial
Agent given to healthy or high-risk individual to prevent disease occurance
What is a therapeutic trial
Agent given to diseased individuals to treat or cure cancer
What are the unit of allocation
Individual trial
Community cluster tiral
What are some things you need to consider when making a population
Want people at in population of intrest
Risk for outcome
Among whom the intervention could be effective
People with highlikelihood of compliance with treatment
Exlcude people with conditions with drug
What does generalizability mean
The extent to which the results from a study can be generalized (or extended) to people who did not partcipate in the study
What are some things that make the study loose generalizabilty
Inclsuion/exclusion criteria
What are some reference population groups to whom results are applicable
All humans
All men, women
Urban children at risk for lead poisoning
What is the population hierachy
Refrence population
Experimental source population ( potiental partcipants)
Study population ( willing and eligible)
Informed Consent Allocation
Treatment group
Comparison group
What board must approve the study
IRB
What is randomization
Each study participant has the same probability of receving treatment
How can radominzation be achieved
Toss a coin
Computer generated
What are bad ways to do randomization
Subject self studies
Day of week order of visit
What should you consider if your group is small
Stratified randomization
What is a confounder in experimental studies
A factor that distorts the true association between an exposure and outcome
What is the ultimate goal
Treatment is the only difference between study groups
When does the two groups are the same
Study is large enough
Treatment assignment is not indluenced by investigator
What is blinding or masking
Method of ensuring that participants and/or study investigators have no knowledge or whether a study participant has been assigned to the treatment or comparison group
What is single blind
Study participant does not know whether they are receiving treatment or no treatment
What is double blind
Neither the study participant or study investigator administering the treatment knows who is receiving treatment or no treatment
What is triple blind
Neither the study partcipant nor the study invesitgator adiministering the treatment or the study investigator monitoring the effects knows
What are some sceneraios where blinidng isnt possible
Such a surgery psychotherpaty
Excercise regimens
diets
What are some ways to minimize information bias
Use a placebo maeks exposded and unexposed groups experinces as comparable as possible
And compliance
What is compliance
Following the study protcol exactly as reqiored throughout the course of the trial
What are the different goals of complaince
- Have groups be alike as possible on other important characteristics (randomization)
- Have groups be as different as possible on exposure( intervetnion)
No contamaniation
What is the worst for compliance
contamination ( inadvertent apllication of the experimental procedure to the control group)