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Flashcards in Behavioral Science - First Aid Deck (160)
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1

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)

2

Measures of a cross-sectional study

-disease prevalence
-can show risk factor association with disease, but does not establish causality

3

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)

4

Measures of a case-control study

-odds ratio

5

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)

6

Meausres of a cohort study

-relative risk

7

Twin concordance study design

compares the frequency with which both monozygotic twins or both dizygotic twins develop the same disease

8

Meausres of a twin concordance study

heritability and influence of environmental factors

9

Adoption study design

compares siblings raised by biological vs adoptive parents

10

Measures of an adoption study

heritability and influence of environmental factors

11

A clinical trial is an experimental study involving humans that compares...

the therapeutic benefits of 2 or more treatments, or of treatment and placebo.

12

Study quality of a clinical trial is improved when the study is...

randomized, controlled and double-blinded.

13

Triple-blind refers to the...

additional blinding ofo the researchers analyzing the data.

14

Phase I Trial

-small number of healthy volunteers
-"Is it safe?"
-Assesses safety, toxicity and pharmacokinetics

15

Phase II Trial

-small number of patients with disease of interest
-"does it work?"
-Assesses treatment efficacy, optimal dosing, and adverse effects.

16

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

17

Phase IV Trial

-posmarketing surveillance trial of pts after approval
-"can it stay?"
-detects rare or long term effects

18

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)

19

A sensitivity value approaching 100% is desirable for...

ruling out disease and indicates a low-false negative rate.

20

High sensitivity tests should be used for screening in diseases with..

low prevalence.

21

Sensitivity =

TP/(TP +FN)

22

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)

23

Specificity value approaching 100% is desirable for...

ruling in disease and indicates a low false-positive rate.

24

High specificity tests should be used for...

confirmation after a positive screening test.

25

Specificity =

TN/(TN + FP)

26

Positive Predictive Value (PPV) is the...

proportion of positive test results that are true positive. The probability that a person actually has the disease given a positive test result.

27

PPV =

TP/(TP + FP)

28

PPV varies...

directly with prevalence or pretest probability. A high pretest probability leads to a high PPV.

29

Negative Predictive Value (NPV) is the...

proportion of negative test results that are true negative. The probability that a person is actually disease free given a negative test result.

30

NPV =

TN/(FN + TN)