Q/A

Question 1

Sensitivity is 90%, PPV is 97%, NPV is 92%, what is overall accuracy?

Answer 1

94% hint- true positives (66) plus true negatives (15) divided by total of all comparisons (90). Accuracy can’t exceed all of the other parameters

Question 2

When making the calculation for sensitivity, what is the numerator?

Answer 2

True positive studies, sensitivity is the # of true positives, divided by total # of positive studies by the gold standard

Question 3

Can be used to clean transducer: n-Alkyl, cidex, diluted bleach

Answer 3

Cannot disinfect w/ sterile saline, not a disinfectant, sterile gel used for intra-op scanning or w/ open wounds

Question 4

Maintains a safe environment:

Answer 4

Electrical checked regularly, emergency team, protocols for certain studies(treadmill), need BLS training. Not every employee respond nessecary

Question 5

Sterile gel is only used for intra-op scanning or w/open wounds

Answer 5

Least likely to transmit infectious agents

Question 6

Accuracy calculation is true positives + true negatives, divided by total of all comparisons. # can’t be greater than PPV #

Answer 6

Tiny bit less than PPV, accuracy will fall between sensitivity & specificity as well as PPV & NPV. Accuracy = true positives plus true negatives divided by total of all comparisons

Question 7

Which statistical parameter would you most likely give the physician in a scan that’s normal?

Answer 7

Negitive predictive value

Question 8

How to calculate sensitivity?

Answer 8

?

Question 9

How to calculate specificity?

Answer 9

Specificity is the # of true negative tests divided by total # of Negitive studies by the gold standard. Ability of test to exclude disease

Question 10

How to calculate sensitivity?

Answer 10

It’s the ability to detect disease, calculated by dividing true positives tests all by positive diagnosis detected by the gold standard. 66 abnormal duplex scans compared to 72 angiography. 66/72. Numerator is true positives

Question 11

Accuracy calculated by?

Answer 11

Determines how good a test is at identifying whether disease is present or not present

Question 12

How is negative predictive value calculated?

Answer 12

Predicts how often a negative study is correct when compared to gold standard. This is calculated by dividing # of true negatives by all negative studies. Whether wrong or right

Question 13

What method of test validation are most helpful in comparing the results of arterial duplex to arteriography?

Answer 13

Sensitivity & specificity

Question 14

Electrical/electronic have safety code requirements, what can prevent any noninvasive evaluation from being done?

Answer 14

Electrical cord is not intact

Question 15

How to calculate positive predictive value(PPV)?

Answer 15

Total # of true positives divided by total # of positive test, whether they are wrong or right

Question 16

Emergency preparedness is part of maintaining a safe environment, what’s least effective?

Answer 16

All personal reporting to supervisor

Question 17

A physician is questioning preliminary findings, the PT’s carotid exam excluded the presence of hemodynamically significant lesion, what parameter would you give the physician?

Answer 17

Negative predictive value

Question 18

How is positive predictive value calculated?

Answer 18

Predicts how often a positive study is correct when compared to the gold standard & calculated by dividing # of true positives by all positive studies(whether wrong or right)