A 28-year-old woman comes to the office due to chronic diarrhea. She also has osteoporosis and anemia. The diagnosis of celiac sprue is considered. An article reviewing the efficacy of 2 new tests available for celiac sprue diagnosis contains the following 2 tables:
Based on these data, which of the following statements is most accurate?

Question

A 28-year-old woman comes to the office due to chronic diarrhea.  She also has osteoporosis and anemia.  The diagnosis of celiac sprue is considered.  An article reviewing the efficacy of 2 new tests available for celiac sprue diagnosis contains the following 2 tables: 
Based on these data, which of the following statements is most accurate?

Quizplus · Accepted Answer

Explanation: 11ec2b69_c103_92c9_8f63_ed12ee21bae4_MD0005_00 The sensitivity of a test refers to its ability to correctly identify individuals with the disease; it can be formulated as TP/(TP + FN), where TP is true positive and FN is false negative. A more sensitive test is able to correctly identify more patients who have the disease (ie, more TPs and fewer FNs) as compared to a less sensitive test. This means that fewer patients with the disease will have a negative result on the more sensitive test. Test Y is more sensitive than test X as it has correctly diagnosed 65 (TPs) of the 80 sprue cases, whereas test X has correctly identified only 60 of the 80. Furthermore, test Y has missed only 15 sprue cases (FNs), whereas test X has missed 20. The specificity of a test refers to its ability to correctly identify individuals without the disease; it can be given by TN / (TN + FP), where TN is true negative and FP is false positive. A more specific test is able to correctly identify more patients who are healthy (ie, more TNs and fewer FPs) as compared to a less specific test. This means that fewer patients without the disease will have a positive result on the more specific test. Test Y is also more specific than test X as it has misdiagnosed only 50 (FPs) of the 320 patients without the disease, whereas test X has misdiagnosed 60 of the 320 healthy patients. Educational objective: A test is more sensitive when it is able to correctly diagnose more patients who have the disease (ie, more true positives and fewer false negatives). This means that fewer patients with the disease will have a negative result on that test. A test is more specific when it is able to correctly identify patients who are healthy (ie, more true negatives and fewer false positives). This means that fewer patients without the disease will have a positive result on that test.

A 28-Year-Old Woman Comes to the Office Due to Chronic