Behavioral Flashcards
(41 cards)
Describe a Case control study. What does it compare and ask?
Compares a group with a disease to another group w/o disease.
Looks for prior exposure or risk factor
asks: “What happened?”
What is measurement for case control study?
Odds ratio
What does a Cohort study ask?
If prospective: “Who will develop disease?”
If retrospective: “Who developed the disease [exposed vs nonexposed]?”
What does cohort study look at?
See if exposure increases chances of disease
Compares group with exposure to group w/o it
Measure used in cohort study?
Relative Risk
Describe a cross-sectional study
Collects data from a group of people to assess frequency of disease (and related risk factors) at a particular point of time
Disease prevalence & risk factor association w/ disease (but not established casually)
What is a Adoption study?
Compares siblings raised by biological Vs. Adoptive parents
Measures heritability influence and environmental influence
Describe Twin concordance study
Compares frequency to develop same disease between monozygotic twins or both dizygotic twins
Measures heritability
what is double-blinded characteristic of a clinical trial?
Neither patient nor doctor knows whether patient is in the Tx or control group
What is a triple-blinded characteristic of a clinical trial?
Neither patient nor doctor knows whether patient is in the Tx or control group
PLUS, researchers analyzing data are blinded
What improves a clinical trial quality?
- Randomized
- Controlled
- Double-blinded
What does a clinical trial look at?
Compares therapeutic benefits between:
- 2 or more treatments
- or bwn treatment & placebo
What does phase 1 of study look at?
Sample size?
Looks at
- safety
- toxicity
- pharmacokinetics
size: small # healthy volonteers
Phase II of a study purpose and size
assess
- Tx efficacy (the ability to produce a desired or intended result.)
- Optimal dosing
- S/E
size: small # of patients w/ interested disease
Phase III study purpose and size
Compares new Tx to current standard of care
size: large # pts, randomly assigned to:
- tested Tx or current Tx
- tested Tx or placebo
Describe phase 4 study size and purpose
Detect rare or long term S/E
size: Postmarketing surveillance trial of patients AFTER APPROVAL
Formula for Sensitivity?
= TP/ (TP+FN)
= 1- FP rate
What is sensitivity for test?
Proportion of all people with disease (TP + FN) who test positive for disease (TP)
Sensitivity Rules out (SNOUT!)
What does a test near 100% sensitivity mean?
Low FN rate
If it = 100%, then FN = 0
Formula for Specificity?
= TN/ (TN + FP)
= 1- FP rate
What is Specificity?
- Proportion of all people w/o disease tested negative
- Ruling In, “SPIN”!
meaning of test with near or exact 100% specificity?
Indicates low FP rate. If = 100%, then FP = 0
When is specificity used? (What type of test)
Confirmatory test!
i.e. for HIV, Western blot has highly specific w/ a high false negative rate
(compare to ELISA, w/ high FP and more sensitive)
Whast is PPV formula?
TP/ (TP +FP)
