Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

PHM > Evidence-Based Medicine > Flashcards

Evidence-Based Medicine Flashcards

(78 cards)

Start Studying
0
Q

P value

A

The probability of obtaining the observed result by chance rather than as a result of accrue effect

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

Alpha level

A

The highest risk of making false positive error that the investigator is willing to accept

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

Bayes theorem

A

If result is positive, probability that patient has the disease
If result is negative, probability that patient doesn’t have disease

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

attributable risk percent in there exposed

A

Among those exposed to y, what % of total risk for disease x is attributable to y

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

Population attributable risk percent

A

Among the population, what % of x is caused by exposure to y

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

Population attributable risk

A

Among the general population, how much of the total risk of fatal disease x is caused by exposure to y

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

Risk difference

A

A measure of absolute risk, aka attributable risk…. The risk in there exposed group minus the risk in the unexposed group

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

Rate difference

A

The rate in the exposed group minus the rate in higher unexposed group

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

Relative risk = risk ratio

A

The ratio of the risk in the exposed group to the risk in the unexposed group. If rr < or = 1, no association or negative association

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

Mortality ratio

A

Occurrence mortality in intervention group relative to controls

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

Strengths and weaknesses of: rct

A

Large numbers of participants
Less bias
Gold standard for testing hypotheses

Unethical to test harmful exposures
Expensive

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

Strengths and weaknesses of: cohort study

A

Can measure multiple outcomes for any one exposure
Can demonstrate a direction on causality
Can measure incidence and prevalence

Prone to loss of follow up bias
Confounding (non randomised)
Costly and time consuming

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

Want kind of study measures one outcome and many risk factors?

A

Case control

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

Want kind of study is susceptible to late look bias

A

Cross sectional

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

Want kind of study is based on exposure

A

Cohort

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

Want kind of study is based on known cases

A

Case control

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

What study is really good for rare diseases

A

Case control

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

Ecological fallacy

A

Inferences drawn to individuals based on populations

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

Want kind of study is good for interesting/new/unusual cases

A

Case series

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

What studies can test a hypothesis

A

Rct ( gold standard) or case control or cohort or ecological

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

Which is stronger and why: prospective or retrospective cohort

A

Prospective, due to the ability to monitor and control data collection

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

Provide and example of stratified allocation

A

Even spread across different blocks

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

What is the goal of case control studies

A

To determine differences in risk factors in participants with a particular outcome and participants without the outcome

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

A t-test measures how ______ the _________ is between two ______

A

Big the difference is between two means

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
A t-test takes into account the:
Variability between score and distributions
25
A 95% confidence interval asserts that
If there experiment were replicated 100 times, 95 of those times would contain the population parameter
26
Unlike probability values, confidence intervals provide information about the _____ of an estimate
Precision :)
27
The standard error is
A measure of precision of a SAMPLE statistic
28
A standard deviation is
A measure of precision of the POPULATION DISTRUBTION
29
Which hypothesis would you reject if t< critical value?
Alternative
30
Which hypothesis would you accept if t< critical value?
Null hypothesis
31
What is the critical level?
A number found in a table that you compare the t-test too to determine significance.
32
You want t to be _____ critical value for significant findings
Greater than
33
In a false positive error, you incorrectly accept the _____ hypothesis
Alternative
34
When the data represents pre-trial and post-trial results for a single group of subjects, use a _________ t test
Paired
35
What does a negative t score indicate?
That pretrial values were greater than post trial values...ie there has been a reduction
36
Risk difference
The proportion of the risk in the exposed that is due to or attributable to the exposure
37
A harmful exposure will yield a _______ greater than 1
Risk difference
38
Odds ratios are useful in ______ study designs
Case control
39
Bayes is used in medicine in:
``` Analysis of clinical decisions in Community screening program Individual patient care By Calculating ppv and posterior probabilities ```
40
In bayes theorem the numerator represents
True positive results
41
When applying bayes theorem to the care of an individual patient, try prior probability is analogous to....
Prevalence
42
To apply bayes theorem to a screening program which 3 bits of information should be known
Prevalence, specificity and sensitivity
43
As an equation, Probability =
Number of favourable outcomes/ | Number of possible equally likely outcomes
44
In a normal distribution ___% fall either side 1SD, and ___% 2SD
68 and 95
45
Alpha can/cannot be used as the basis for ejecting the nul hypothesis
Can
46
Inductive reasoning
Specific to general | Generalising
47
Deductive reasoning
General to specific | Deducing
48
Binomial probability distribution
Used to describe variables with two levels
49
What is the advantage of an observational experimental design?
Can be used where it is unethical to withhold a treatment
50
What does a correlational study design measure?
Association, not causation
51
Nominal and ordinal are__________. | We use _________ correlation for ORDINAL data.
Non parametric | Spearman's
52
Nominal data
Categories that have no relationship to each other e.g. Blood type
53
Ordinal data
Categories that have a relationship e.g. Young middle-aged and old
54
Interval and ratio data are_____. We use _________ correlation
Parametric types of data. | Pearson's
55
Interval data
Related but no absolute zero e.g. Iq
56
Ratio data
Parametric data with absolute zero e.g. Blood pressure
57
Chi square test is a measure of________ that allows us to calculate ________
Difference, not association | Statistical significance
58
Define correlation
A measure of association between variables
59
When do you use a student's t-test?
When there are two separate groups of participants
60
What is the difference between t tests and z tests?
T tests measure differences in means | Z tests measure differences in proportions
61
Critical ratio
Uses t or z test to a calculate a ratio between a parameter and the SE of that parameter
62
The nul hypothesis for a chi squared test of a 2x2 contingency table is that:
The two variables are independent of each other (variation in one variable is not caused in part but variation in another variable)
63
What category does an interventional study design fall under? Strength and weakness?
Experimental S: reduce ill health in entire community, increase health literacy, behaviours and environment W: limited randomisation and difficulty in follow up
64
What are the phases of drug development/ public health intervention?
``` Basic science (discovery/1) M ethod development (1/2) E fficacy (2/3) E ffectiveness (3/4) D issemination (4/5) ```
65
Strengths and weaknesses of case control
S: less expensive than cohort, good for rare, multiple exposures W: selection, recall and observer bias, only a single outcome, temporal relationships difficult to decipher
66
MR < 1 indicates that there is ______ mortality in the intervention group
Decreased
67
If an attributable risk is <0, factor investigated is protective or harmful?.
Protective
68
Degrees of freedom
N-1 in students | N-2 in paired
69
How do 1 way and 2 way anova differ?
Number of independent variables being tested
70
What kind of data do you use anova on?
Dependent is continuous | Independent is categorical
71
5as
``` Ask Access Appraise Apply Audit ```
72
Picot
People Intervention Comparison control Outcome
73
Why can't we calculate incidence in a case control study ?
The study population has been selected on the basis of hype heir disease
74
Attributable risk
Ar = risk(ex) - risk(unex)
75
Relative risk equation
Risk(ex) / risk(unex)
76
OR
Ad/bc
77
Ar(%)
= [risk(ex) - risk(unex)] / risk(unex) (x100)

PHM (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions