RVT Vascular Registry Review QUESTIONS WITH COMPLETE SOLUTIONS

Sensitivity CORRECT ANSWERS: the ability of a test to detect disease (how many noninvasive results were correctly called positives on the basis of the gold standard results?) How do you calculate sensitivity? CORRECT ANSWERS: Number of true positive diagnoses / true positive + false negative Specificity CORRECT ANSWERS: the ability of a test to identify normality (of the gold standard negatives, how many did you correctly call negative on the basis of the noninvasive results) How do you calculate specificity? CORRECT ANSWERS: number of true negative diagnoses / true negative + false positive Positive predictive value CORRECT ANSWERS: the percentage of non invasive test results that accurately predict abnormality (accurately predicted disease as supported by the gold standard) How to calculate positive predictive value? CORRECT ANSWERS: Number of true positive / number of true positive + number of true negative Negative predictive value CORRECT ANSWERS: the percentage of noninvasive test results that accurately predict normality. (of your negative noninvasive studies, what percentage correctly predicted the absence of disease as supported by the gold standard) How to calculate negative predictive value CORRECT ANSWERS: number of true negative noninvasive tests / number of true negative + number of true positive Accuracy CORRECT ANSWERS: Percentage of correct noninvasive diagnoses (how well does the noninvasive test both detect and rule out disease?) How to calculate accuracy CORRECT ANSWERS: total number of correct tests (true positive + true negative) /total number of all studies TRUE POSITIVE CORRECT ANSWERS: You (the vascular laboratory) said abnormal and the gold standard said abnormal. You both agree that the results are positive. FALSE POSITIVE CORRECT ANSWERS: You (the vascular laboratory) said abnormal, and the gold standard said normal. The noninvasive study said positive, but it is wrong - a false positive. FALSE NEGATIVE CORRECT ANSWERS: You (the vascular lab) said normal, but the gold standard said abnormal. The noninvasive study said negative, but is wrong - a false negative TRUE NEGATIVE CORRECT ANSWERS: You (the vascular lab) said normal, and the gold standard said normal. You both agree that the test results are negative.