Ch. 4 Research Principles Flashcards Preview

ACAAI Review 3rd Edition > Ch. 4 Research Principles > Flashcards

Flashcards in Ch. 4 Research Principles Deck (40):
1

Data regarding presence or absence of exposure and disease are collected at the same time

Cross sectional study

2

Compares subjects with a condition to those without and examines frequency of a risk factor in each group

Case Control

3

study that is useful in studying infrequent events and calculated odds ratio

Case Control

4

study that is the gold standard in observational epidemiology and calculate relative risk

Cohort Study

5

longitudinal study comparing a defined group of people who share a common experience within a defined period before developing outcome of interest

Cohort study

6

subjects allocated to different interventions, placebo versus treatment group

RCT randomized control trial

7

study that can be used to test preventive interventions and determine absolute risk reduction

RCT

8

statistical test to compare means between two groups

student's t-test or Wilcoxon rank sum test

9

statistical test to compare means between 3 or more groups

ANOVA or Kruskal-Wallis test

10

statistical test to compare two quantitative measurements from one source

paired t test or Wilcoxon signed rank test

11

statistical test to determine degree of association between to quantitative variables

Pearson coefficient of correlation or Spearman rank order coefficient

12

Hypothesis that there is no effect or no difference is called?

Null hypothesis

13

the probability that if the null hypothesis were true, we would observe a result as extreme than one observed in these study

P value

14

error that occurs when the null hypothesis is falsely rejected and we accept that a difference exists when it truly does not

type 1 error or alpha error

15

error that occurs when the null hypothesis is not rejected when a true difference exists

type 2 error or beta error

16

most common reason for a type 2 or beta error (not rejecting the null hypothesis)

underpowered study

17

ability of a test to detect a true difference in a data set or the probability of avoiding a type II error

Statistical power

18

statistical power is usually set to what percentage

80 to 90%

19

if the null hypothesis is true and you accept the null hypothesis, what is the probability?

1 - alpha

20

if the null hypothesis is true and you reject the null hypothesis, what is the probability?

alpha

21

if the null hypothesis is false and you accept the null hypothesis, what is the probability?

beta

22

if the null hypothesis is false and you reject the null hypothesis, what is the probability?

1-beta (equal to power)

23

what percentage of observations fall within 1 SD, 2 SD, 3 SD of the bell shaped curve?

68%, 95%, 99.7%

24

Difference between prevalence and incidence?

prevalence is percentage of patients with disease at a given time, and incidence is measure of individuals that develops disease during a specified period

25

Probability that a test will be positive for disease if the person has the disease

sensitivity = TP / (FN + TP)

26

Probability that a test will be negative if person does not have the disease

specificity = TN / (FP + TN)

27

a negative result for a highly sensitive tests can...?

rule out disease

28

a positive result for a highly specific tests can...?

rule in disease

29

the proportion of positive tests that are true positive

PPV = TP / (TP+FP)

30

the proportion of negative tests that are true negative

NPV = TN / (TN + FN)

31

PPV and NPV are affected by?

prevalence

32

How will PPV and NPV be affected by prevalence?

high prevalence increases PPV, low prevalence increases NPV

33

equation for absolute risk (AR)

ARC = # of events in control group / # of people in control group
ART = # of events in treatment group / # of events in treatment group

34

equation for absolute risk reduction (ARR)

ARR = ARC - ART

35

equation for relative risk

RR = ART / ARC

36

equation for relative risk reduction

RRR = (ARC - ART) / ARC = 1 - RR

37

equation for number needed to treat

NNT = 1/ARR

38

equation for odds ratio OR

OR = (TP x TN) / (FP x FN)

39

three core principles in the Belmont Report

respect for persons, beneficence, justice

40

5 elements of informed consent

competence, disclosure, understanding, voluntariness, consent