Behavioral Science - First Aid Flashcards
Cross-sectional study (observational) design
collects data from a group of people to assess frequency of disease at a particular point in time
(asks what is happening)
Measures of a cross-sectional study
- disease prevalence
- can show risk factor association with disease, but does not establish causality
Case-control study (observational/retrospective) design
compares a group of people with disease to a group without disease; looks for prior exposure or risk factor
(asks what happened)
Measures of a case-control study
-odds ratio
Cohort study (observational/prospective or retrospective) design
compares a group with a given exporsure or risk factor to a group without such exposure; looks to see if exposure increases the likelihood of disease
(prospective - asks who will develop disease)
(retrospective - asks who has developed the disease)
Meausres of a cohort study
-relative risk
Twin concordance study design
compares the frequency with which both monozygotic twins or both dizygotic twins develop the same disease
Meausres of a twin concordance study
heritability and influence of environmental factors
Adoption study design
compares siblings raised by biological vs adoptive parents
Measures of an adoption study
heritability and influence of environmental factors
A clinical trial is an experimental study involving humans that compares…
the therapeutic benefits of 2 or more treatments, or of treatment and placebo.
Study quality of a clinical trial is improved when the study is…
randomized, controlled and double-blinded.
Triple-blind refers to the…
additional blinding ofo the researchers analyzing the data.
Phase I Trial
- small number of healthy volunteers
- “Is it safe?”
- Assesses safety, toxicity and pharmacokinetics
Phase II Trial
- small number of patients with disease of interest
- “does it work?”
- Assesses treatment efficacy, optimal dosing, and adverse effects.
Phase III Trial
- large number of pts randomly assigned either to the treatment under investigationor to the best available treatment/placebo
- asks “is it as good or better?”
- compares new treatment to current standard of care
Phase IV Trial
- posmarketing surveillance trial of pts after approval
- “can it stay?”
- detects rare or long term effects
Sensitivity is the…
proportion of all people with a disease who test positive or the probability that a test detects disease when it is present. (true-positive rate)
A sensitivity value approaching 100% is desirable for…
ruling out disease and indicates a low-false negative rate.
High sensitivity tests should be used for screening in diseases with..
low prevalence.
Sensitivity =
TP/(TP +FN)
Specificity is the…
proportion of all people without disease who test negative or the probability that a test indicates non-disease when disease is absent. (true-negative rate)
Specificity value approaching 100% is desirable for…
ruling in disease and indicates a low false-positive rate.
High specificity tests should be used for…
confirmation after a positive screening test.