Lecture 1B (EBP principles on diagnostic testing)

Question 1

______ of data is vital to accurate and efficient clinical decision-making

Answer 1

quality

Question 2

evidence supporting best ______ and ______ for exam and re-exam

Answer 2

test and measures

Question 3

evidence to determine how to best ______ _____ for pt management

Answer 3

integrate data

Question 4

psychometric properties: reliability and validity

Answer 4

reliable: is it constant
validity: does it measure what we believe it measures

Question 5

responsiveness

Answer 5

ability to detect change overtime in the measured construct

Question 6

what are common PT constructs?

Answer 6

• ROM/Flexibility
• muscle strength
• pain
• outcome measures

Question 7

sensitivity

Answer 7

(snOUT)
- given that the individual has the condition, probability that test will be (+), ability to identify condition correctly
- high sensitivity, so when (-), helps RULE OUT

Question 8

Specificity

Answer 8

(spIN)
- given that the individual does NOT have the condition, probability that test will be (-)
- high specificity value, that when (+), helps RULE IN a condition
ability to exclude a condition correctly

Question 9

which test is a true positive rate? what about negative?

Answer 9

+ : sensitivity (snOUT)
- : specificity (spIN)

Question 10

sensitivity equation

Answer 10

TP/(TP+FN)

proportion of ppl w disease that tested positive
- true positive rate

Question 11

specificity equation

Answer 11

TN/(TN+FP)

proportion of ppl W/O disease that test negative
- true negative rate

Question 12

high sensitivity

Answer 12

True positive (people who have the disease and test positive)
few false negatives

Question 13

high specificity

Answer 13

few false positives
true negative

Question 14

screening for a test is _____, and diagnostic test is _____

Answer 14

sensitivity
specificity

Question 15

positive predictive value

Answer 15

given a positive test, the probability that the individual has the condition

true positive / (true positive + false positive)

Question 16

negative predictive value

Answer 16

given a negative test, the probability that the individual does not have the condition

true negative / (true negative + false negative)

Question 17

limitations using predictive values

Answer 17

• sample specific
• it depends on the PREVALENCE of condition

Question 18

why are predictive values affected by the prevalence?

Answer 18

if there is a lower prevalence of something:

there will be higher negative predictive values
and a lower positive predictive value

Question 19

useful test should produce ____ ___ in probability given a certain test result. they should tell you something that helps you make a clinical decision

Answer 19

large shift

Question 20

which values are helpful but do not provide the entire picture (aka produce a large shift in probability)?

Answer 20

sensitivity and specificity

Question 21

what type of equation QUANTIFIES shifts in probability given a certain test result
(& combines sensitivity and specificity values)

Answer 21

likelihood ratios

Question 22

positive likelihood ratio
given a positive test result, it ______ in odds favoring the condition
ration of TRUE POSITIVE rate to the FALSE POSITIVE rate

Answer 22

increases

Question 23

LR + equation

Answer 23

LR+= sensitivity / (1 - specificity)

Question 24

LR- equation

Answer 24

LR- = (1-sensitivity) / specificity

Question 25

what does a positive Likelihood ration confirm?

Answer 25

more certainty that individual HAS the condition

Question 26

negative likelihood ratio
given a negative result, _____ in odds favoring the condition
ratio of FALSE NEGATIVE rate to the TRUE NEGATIVE rate

Answer 26

decrease

Question 27

with a negative test, IF the negative likelihood ratio close to zero …

Answer 27

the odds that the individual has the condition is LESS (more powerful)

Question 28

what is the most powerful tool for quantifying importance of a particular test?

Answer 28

LRs

Question 29

a Positive LR:

greater than ____ generates large, often conclusive shifts in probability.
between __-__ generates moderate shifts
between __-__ generates, small but sometimes important, shifts in probability
between __-__ alter probability to small, rarely important, degree

Answer 29

10
5-10
2-5
1-2

Question 30

a Negative LR:

less than ___ generates large, often conclusive shifts in probability.
between __-__ generates moderate shifts
between __-__ generates, small but sometimes important, shifts in probability
between __-__ alter probability to small, rarely important, degree

Answer 30

< 0.10
0.1 - 0.2
0.2 - 0.5
0.5 - 1

Question 31

negative LR closer to 1

Answer 31

not good at ruling out

Question 32

positive LR closer to 0

Answer 32

not good at ruling in

Question 33

____ statistic used to represent amount of change needed to exceed measurement error of the test. reliability measure of change

Answer 33

minimal detectable change

Question 34

what happens to the MCD value if there is INCREASED reliability of test?

Answer 34

decrease

Question 35

____ provide MOST powerful tool for quantifying importance of a particular test

Answer 35

LRs

Question 36

____ smallest diff detected that represents an IMPORTANT IMPROVEMENT from perspective of individuals with the condition

Answer 36

minimal clinical important difference (MCID)
more than the avg error of 5 % ?

Question 37

T/F: the MCID should exceed MCD

Answer 37

true

Question 38

Is the change enough to matter to the pt and their goals?

Answer 38

YES–

MCID should be higher than measurement error