Biostats Flashcards

1
Q

Relative risk formula

A

risk in tx group / risk in control group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

In this type of distribution, the mean, median, and mode are the same value.

A

normal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

retrospective comparisons of cases (patients with a disease) and controls (patients without the disease)

A

case control study

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

retrospective or prospective comparisons of patients with an exposure to those without an exposure

A

cohort study

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Which of the following statements are true regarding the p-value?

a. If the alpha in a study is 0.01, p < 0.05 indicates the result is statistically significant.
b. It represents the level of clinical significance.
c. A study result is considered statistically significant if the p-value is less than alpha.
d. It provides info for rejecting or not rejecting the null hypothesis.
e. It can be set to any number by the investigator and be clinically relevant.

A

c, d

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

NNT formula

A

1 / (risk in control group - risk in tx group)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

(% risk in control group) - (% risk in tx group)

A

absolute risk reduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

describes how effectively a test identifies patients with the condition

A

sensitivity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

describes how effectively a test identifies patients without the condition

A

specificity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

This type of analysis can be used to compare programs with similar or unrelated outcomes, as long as the outcome measures can be converted to dollars.

A

cost-benefit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Rank the studies from most reliable to least reliable:

Case control studies
Randomized controlled trials
Meta-analyses
Cohort studies
Case series

A

Meta-analyses, randomized controlled trials, cohort studies, case control studies, case series

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

This type of study combines data from different, but related studies, in order to increase the power of the study.

A

meta-analysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What kind of error occurs when the alternative hypothesis is accepted and the null hypothesis is rejected in error?

A

type 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What kind of error occurs when the null hypothesis is accepted when it should have been rejected?

A

type 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

represents the spread (or variability) of data from the mean when data is normally distributed

A

standard deviation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

this type of analysis is used to compare the clinical effects of 2 or more interventions to the retrospective costs

A

cost-effectiveness

17
Q

A study comparing drug A to placebo determined that the relative risk reduction in all-cause mortality was 0.33. Which of the following statements is correct?

a. Patients who received drug A were 67% less likely to die compared to patients in the placebo group
b. Patients who received drug A were 33% as likely to die as patients in the placebo group
c. For every 100 patients who received drug A, 33 fewer died compared to patients in the placebo group
d. Patients who received drug A were 33% less likely to die compared to patients in the placebo group
e. 33 patients needed to be treated with drug A to prevent one death

A

d

18
Q

Includes data for all patients originally allocated to each treatment group (active and control) even if the patient did not complete the trial according to the study protocol (e.g., due to non-compliance, protocol violations or study withdrawal).

A

intention-to-treat analysis

19
Q

conducted for the subset of the trial population who completed the study according to the protocol (or at least without any major protocol violations)

A

per protocol analysis

20
Q

hazard ratio formula

A

(hazard rate of tx group) / (hazard rate of control group)

21
Q

In a clinical trial, what do the independent variables include?

A

intervention (drug, dose, frequency), comparator arm (placebo, active drug), and inclusion criteria

22
Q

implies no difference in risk of the outcome between the groups

A

RR = 1

23
Q

implies greater risk of the outcome in the treatment group

A

RR > 1

24
Q

implies lower risk of the outcome in the treatment group

A

RR < 1

25
Q

If a study with metoprolol had a RR of 57%, what is the correct interpretation?

a. Patients that received metoprolol were 57% less likely to have progression of disease as placebo-treated patients.
b. Patients that received metoprolol were 57% as likely to have progression of disease as placebo-treated patients.

A

b

26
Q

used for continuous data when the study has 2 independent samples

A

student t-test

27
Q

used to test for statistical significance when using continuous data with 3 or more samples, or groups

A

ANOVA

28
Q

for nominal or ordinal data, this test is used to determine statistical significance between treatment groups

A

chi square test