Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

NAPLEX 2024 > 14. Biostats > Flashcards

14. Biostats Flashcards

1
Q

2 types of continuous data

A

interval data and ratio data

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

Interval data definition and example

A

No meaningful zero (zero does not equal none)
Example: temperature scale (0 celcius does not mean no temp)

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

Ratio data definition and example

A

Meaningful zero (zero equals none)
Example: HR (0 BPM is cardiac arrest)

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

2 types of discrete data

A

nomial and ordinal

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

Nomial data definition and example

A

Subjects are sorted into arbitrary categories (names) , order of categories does not matter
Example: gender, ethnicity, martial status, mortality

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

Ordinal data defintion and example

A

Ranked and has a logical order
Example: pain scale
Note: ordinal scale categories do not increase by the same amount (pain scale 4 is not necessarily 2x more than pain scale 2)

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

In normal distributions, ___% of values fall within 1 standard deviation of the mean

A

68%

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

In normal distributions, ___% of the values fall within 2 standard deviations of the mean

A

95%

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

In normal distributions, 99.7% of the values fall within ___ standard deviations of the mean

A

3 SDs

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

More lower values in data set and outliers are high values, data is skewed to (left/right), aka (negative/positive) skew

A

Right, positive

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

More higher values in data set and outliers are low values, data is skewed to (left/right), aka (negative/positive) skew

A

Left, negative

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

T/F: the null hypothesis and alternative hypothesis are always complementary; when one is accepted, the other is rejected

A

True

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

Define null hypothesis

A

There is no statistically significant difference between groups

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

Alpha (error margin) is the threshold for rejecting the null hypothesis. In medical research, alpha is commonly set at ____

A

5% or 0.05

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

T/F: If the p-value is less than alpha, the null hypothesis is rejected

A

True

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

T/F: If the p-value is greater than alpha, the null hypothesis is rejected

A

False - if p-value is greater than alpha, the study failed to reject the null hypothesis and results are not statistically significant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

If alpha is 0.05, the study reports ___% confidence intervals

A

95%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

If p-value is <0.01, it means __% probability (confidence) that the conclusion is correct; less than __% change it’s not

A

99% confidence, 1% chance it’s not

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

When comparing difference data (means, based on subtraction), the result is statistically significant if the CI range does not include ___

A

zero

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

When comparing ratio data (relative risk, odds ratio, hazard ratio, based on division), the result is statistically significant if the CI range does not include ___

A

one

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

A (narrow/wide) CI range implies high precision and a (narrow/wide) CI range implies poor precision

A

narrow, wide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

False positive is considered to be a type __ error (null hypothesis was rejected in error)

A

Type 1 error

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

False negative is considered to be type __ error (null hypothesis is accepted when it should have been rejected)

A

Type 2 error

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Study __ is the probability that a test will reject the null hypothesis corrected (i.e. the power to avoid a type 2 error)

A

Study power

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Type 2 error is denoted as __

A

beta (ß)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Power equation

A

Power = 1 - ß

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

If beta is set at 0.2, the study has __% power which means there is a __% chance of missing a true difference and making a type ___ error

A

80%, 20%, type 2 error

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

____ is the ratio of risk in the exposed group (treatment) divided by risk in the control group

A

Relative risk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Relative risk formula

A

RR = risk in treatment group / risk in control group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

RR=1 (100%) implies ____ risk of outcomes in the treatment group

A

no difference (compared to control)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

RR > 1 (100%) implies ___ risk of outcomes in the treatment group

A

greater

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

RR < 1 (100%) implies ___ risk of outcomes in the treatment group

A

lower

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Relative risk reduction (RRR) formula

A

RRR = (%risk in control - % risk in treatment) / % risk in control group
RRR = 1 - RR (decimal form)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Absolute risk reduction (ARR) formula

A

ARR = (% risk in control) - (% risk in treatment)

35
Q

ARR of 12% interpretation

A

12 out of every 100 patients benefit from the treatment
For every 100 patients treated, 12 fewer patients will have the outcome

36
Q

____ is the number of patients who need to treat for a certain period of time in order for 1 patient to benefit

A

Number needed to treat (NNT)

37
Q

Number needed to treat (NNT) and Number needed to harm (NNH) formula

A

NNT (or NNH) = 1 / (risk in control - risk in treatment)
NNT (or NNH) = 1 / ARR
*risk and ARR expressed as decimals

38
Q

If ARR is 12%, what is the NNT?

A

NNT = 1/0.12 = 8.3 –> rounded to 9

39
Q

____ is the number of patients need to treat for a certain period of time in order for 1 patient to experience harm

A

Number needed to harm (NNH)

40
Q

NNT is rounded (up/down) and NNH is rounded (up/down)

A

Up, down

41
Q

NNH 90 interpretation

A

One additional case of outcome expected to occur for every 90 patients taking treatment vs placebo

42
Q

___ is used to estimate the risk of unfavorable events a/w treatment or intervention

A

Odds ratio

43
Q

Odds ratio (OR) formula

A

OR = AD/BC
A-Treatment outcome present
B-Treatment outcome absent
C-Control outcome present
D-Control outcome abset

43
Q

In a survival analysis, ___ is the rate at which an unfavorable event occurs within a short period of time

A

Hazard ratio

43
Q

Hazard ratio (HR) formula

A

HR = Hazard rate in treatment / hazard rate in control

43
Q

OR or HR = 1 interpretation

A

event rate is same in both groups

44
Q

OR or HR > 1 interpretation

A

Event rate is higher in treatment group

45
Q

OR or HR < 1 interpretation

A

Event rate is lower in treatment group

46
Q

___ t-test is used when data from a single sample group is compared with known data from the general population

A

One-sample t-test

47
Q

___ t-test is used when a single sample group is used for a pre-/post-measurement

A

Paired t-test

48
Q

___ t-test is used when the study has 2 independent samples: treatment and control groups

A

Student t-test

49
Q

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

A

Analysis of variance (ANOVA) or F-test

50
Q

For nominal or ordinal data, a ___ test is used to determine statistical significance between treatment groups

A

Chi-square

51
Q

(sensitivity/specificity) describes how effectively a test identifies patients WITH the condition

A

Sensitivty

52
Q

(sensitivity/specificity) describes how effectively a test identifies patients WITHOUT the condition

A

Specificity

53
Q

Sensitivity formula
A-Positive test, have condition
B-Positive test, does not have condition
C-Negative test, have condition
D-Negative test, does not have condition

A

Sensitivity = A / (A+C) x 100

54
Q

Specificity formula
A-Positive test, have condition
B-Positive test, does not have condition
C-Negative test, have condition
D-Negative test, does not have condition

A

Specificity = D / (B+D) x 100

55
Q

Sensitivity of 28% interpretation

A

Only 28% of patients with the condition will have a positive RF result, test will be negative in 72% of patients with disease (missed dx)

56
Q

Specificity of 87% interpretation

A

Test will be negative in 87% of patients without the disease but 13% of patients without the disease may test positive (false dx)

57
Q

___ analysis includes data for all patients originally allocated to each treatment group even if they did not complete the trial

A

Intention to Treat

58
Q

___ analysis only include data for patients who completed the trial

A

Per protocol

59
Q

Name type of study: retrospective comparisons of cases (patients with a disease) and controls (patients without a disease)

A

Case-control study

60
Q

Name type of study: retrospective or prospective comparisons of patients with an exposure to those without an exposure

A

Cohort studies

61
Q

Name type of study: prospective comparison of patients who were randomly assigned to groups

A

Randomized controlled trials

62
Q

Name type of study: analyzes the results of multiple studies

A

Meta-analysis

63
Q

What type of study is most reliable?

A

Systematic reviews and meta-analysis

64
Q

List type of studies in order of most reliable to least reliable:
Expert opinion, cohort studies, case series and reports, case-controlled studies, randomized controlled trials, systematic reviews and meta-analysis

A

Systematic reviews and meta-analysis
Randomized controlled trials
Cohort studies
Case-controlled studies
Case series and case reports
Expert opinion

65
Q

Examples of direct medical costs

A

Drug prep and administration (including home infusion supplies)
Inpatient direct costs: hospital bed, administration, medical staff, surgeries, procedures, labs
Outpatient direct costs: office and clinical visits

66
Q

Examples of direct non-medical costs

A

Travel and lodging costs for patients and caregivers traveling to hospital or clinic
Household costs such as childcare or elder care
Home health aides, to help with dressing/bathing and other ADLs

67
Q

Examples of indirect costs

A

Lost work time
Low work productivity
Morbidity: costs from having the disease and related disability
Mortality (death)

68
Q

Examples of intangible costs

A

Pain, suffering, anxiety, fatigue

69
Q

What type of cost?: A caregiver was hospitalized and needs to pay for eldercare

A

Non-medical direct cost

70
Q

What type of cost?: Traveling and lodging costs to get to hospital/clinic

A

Non-medical direct cost

71
Q

What type of cost?: pain/suffering

A

Intangible

72
Q

What type of cost?: Lost work time

A

Indirect

73
Q

What type of cost?: Morbidity (costs from having disease and related disability)

A

Indirect

74
Q

____ represents the change in costs and outcomes when 2 treatment alternatives are compared

A

Incremental cost-effectiveness ratios

75
Q

Incremental cost ratio formula

A

Incremental cost ratio = (C2 - C1) / (E2 - E1)
C-costs
E-effects

76
Q

____ is used when 2 or more interventions have demonstrated equivalence in outcomes and the costs of each intervention are being compared

A

Cost-minimization analysis (CMA)

77
Q

____ is a systematic process for calculating and comparing benefits and costs of an intervention in terms of monetary units (dollars)

A

Cost-benefit analysis (CBA)

78
Q

____ is used to compare the clinical effects of 2 or more interventions to the respective costs

A

Cost-effective analysis (CEA)

79
Q

Cost minimization analysis limitation

A

Can only compare alternatives with demonstrated equivalent outcomes
(example: captopril vs lisinopril, both considered therapeutically equivalent in literature)

80
Q

Cost effectiveness analysis limitation

A

Cannot compare different types of outcomes
(example: asthma program vs diabetes program)

81
Q

____ is a specialized form of CEA that includes QOL component of morbidity assessments (QALY or DALYs)

A

Cost-utility analysis

NAPLEX 2024 (74 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions