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