A patient without a history of hypertension undergoes a screening test for high blood pressure. The test correctly identifies 90% of individuals without hypertension. Which of the followings term best describes the probability of a negative test result when the disease is absent?
D) Specificity
Specificity is the probability of a negative test result when the disease is absent. It is defined as true negatives/(true negatives + false positives). In this case, specificity represents the ability of the test to correctly identify individuals without hypertension.
Answer choice A: Negative predictive value, is incorrect. Negative predictive value is the probability that a negative test result truly indicates the absence of the disease. It is calculated as true negatives/(true negatives + false negatives).
Answer choice B: Positive predictive value, is incorrect. Positive predictive value is the probability that a positive test result truly indicates the presence of the disease. It is calculated as true positives/(true positives + false positives).
Answer choice C: Sensitivity, is incorrect. Sensitivity is the probability of a positive test result when the disease is present. It is defined as true positives/(true positives + false negatives).
Answer choice E: True positive rate, is incorrect. True positive rate is synonymous with sensitivity. It represents the proportion of true positives among all individuals with the disease.
Key Learning Point
Specificity is the probability of a negative test result when the disease is absent. It is defined as true negatives/(true negatives + false positives). Specificity is a crucial measure for evaluating the ability of a diagnostic test to correctly identify individuals without the disease.
