UNDERSTANDING THE QUALITY OF DATA IN CLINICAL MEDICINE

Question 1

requires constant collection, evaluation, analysis, and use of quantitative and qualitative data

Answer 1

Clinical medicine

Question 2

is used for diagnosis, prognosis, and choosing and evaluating treatments

Answer 2

Data

Question 3

o Mistakes in the diagnosis and treatment of patients

o Mistakes due to clear negligence

Answer 3

Error

Question 4

First and primary goal of data collection and analysis

Answer 4

Promote accuracy and precision

Question 5

Close to true value

Answer 5

Accuracy

Question 6

Ability of a measurement to be correct on the average

Answer 6

Accuracy

Question 7

Precision is also known as

Answer 7

Reproducibility, reliability, or agreement

Question 8

Ability of a test to give the same result or a similar result with repeated measurement of the same factor

Answer 8

Precision

Question 9

MEASURES OF RELIABILITY

Answer 9

Overall percent agreement

Kappa test ratio

Question 10

Kappa test ratio is also known as

Answer 10

Cohen’s Kappa

Question 11

• Common way to measure agreement

Answer 11

OVERALL PERCENT AGREEMENT (OPA)

Question 12

Percent agreement formula

Answer 12

a+d/
a+b+c+d x 100

Question 13

OPA when there are just 2 people observing

Answer 13

PERCENT AGREEMENT (PAIRED OBSERVATIONS)

Question 14

OPA when there’s a lot of variables invloved

Answer 14

OVERALL PERCENT AGREEMENT (MULTIPLE VARIABLES)

Question 15

Measures the extent to which agreement exceeds that expected by chance

Answer 15

KAPPA TEST RATIO

Question 16

• How much better is the agreement between two observers’ readings than would be expected by chance alone?

Answer 16

KAPPA TEST RATIO

Question 17

• What is the most that the two observers could have improved their agreement over the agreement that would be expected by chance alone?

Answer 17

KAPPA TEST RATIO

Question 18

: happens when the information errors differ between groups

Answer 18

Differential error

Question 19

: happens when the information is incorrect, but is the same across groups

Answer 19

Nondifferential error

Question 20

refers to any systematic error that may occur during the collection of baseline or follow-up data

Answer 20

Measurement bias

Question 21

Variability and unpredictability
results in lack of precision
When data have only _______, some observations are too high and some are too low

Answer 21

Random error

Question 22

Intraobserver variability or

Answer 22

Within the observers

Question 23

Amount of variation between the results obtained by one observer examining the same results more than once

Example: same clinician takes successive blood pressure on the same patient

Answer 23

Intraobserver variability

Question 24

Amount of variation between the results obtained by 2 or more observers examining the same material

Answer 24

Interobserver variability

Question 25

Ability of a test to distinguish between WHO HAS a disease and WHO DOES NOT

Answer 25

Validity

Question 26

is performed as a preventative measure – to detect a potential health problem or disease in someone that doesn't yet have signs or symptoms

Answer 26

screening tests

Question 27

able to correctly identify who has the disease

Answer 27

Sensitivity

Question 28

– correctly identifies who does not have the disease

Answer 28

Specificity

Question 29

Have the disease and test positive

Answer 29

True Positive (TP)

Question 30

Do not have the disease but test positive

Answer 30

False Positive (FP)

Question 31

Have the disease but test negative

Answer 31

False Negative (FN)

Question 32

Do not have the disease and test negative

Answer 32

True Negative (TN)

Question 33

Sensitivity formula

Answer 33

TP/ TP + FN

Question 34

Specificity formula

Answer 34

TN/ TN + FP

Question 35

How about tests with continuous variables? Such as blood pressure or blood glucose levels There is no “positive” or “negative” result

Answer 35

Cutoff points

Question 36

The _______ determines how many subjects will be considered as having the disease

Answer 36

cut-point

Question 37

The cut-point that identifies more true negatives will also identify more ____________

Answer 37

False negatives

Question 38

The cut-point that identifies more true positives will also identify more ____________

Answer 38

False negatives

Question 39

• When two or more tests are conducted in parallel simultaneously ) • Disease positives are identified as those who test positive by either one test or by both tests

Answer 39

SIMULTANEOUS TESTING

Question 40

• After the first (screening) test was conducted, those who tested positive were brought back for the second test to further reduce false positives

Answer 40

SEQUENTIAL (TWO-STAGE) TESTING

Question 41

_: less expensive, less invasive or less uncomfortable

Answer 41

First test/ screening

Question 42

____________: more expensive, more invasive or more uncomfortable

Answer 42

Second test/ confirmatory

Question 43

A ____________, which is used to rule out a diagnosis, should have a high degree of sensitivity.

Answer 43

screening test

Question 44

A _____________, which is used to rule in a diagnosis, should have a high degree of specificity.

Answer 44

confirmatory test

Question 45

/o If something is said to be true when it is actually false

Answer 45

Type 1 terror false-positive error Alpha error

Question 46

o If something is said to be false when it is actually true

Answer 46

Type II False-positive error Beta error

Question 47

o Reliably finding a disease when it is present o Avoids false negative results

Answer 47

Sensitivity

Question 48

Reliably excluding a disease when it is absent Avoids false positive results

Answer 48

Specificity

Question 49

• Describe the probability of having actual disease given the results of a test

Answer 49

PREDICTIVE VALUES

Question 50

Indicates what proportion of the subjects with positive test results actually have the disease

Answer 50

Positive Predictive Value (PPV )

Question 51

Indicates what proportion of the subjects with negative test results actually do not have the disease

Answer 51

Negative Predictive Value (NPV)

Question 52

• “RULE IN DISEASE” • Ratio of the sensitivity of a test to the false-positive error rate of the test

Answer 52

LIKELIHOOD RATIO POSITIVE (LR+)

Question 53

• “RULE OUT DISEASE” • Ratio of the false-negative error rate divided by the specifici

Answer 53

LIKELIHOOD RATIO NEGATIVE (LR-)

Question 54

______ and _______ assess how good a test is at diagnosis of disease while ____________ predicts the risk of disease for a particular test.

Answer 54

Sensitivity and specificity/ likelihood ratio

Question 55

_________ and _________ both predict risk of disease, but, unlike predictive value which depends on the prevalence of the disease, likelihood ratio does not.

Answer 55

Predictive value and likelihood