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: After careful analysis of the data from the 2 tables, a decision is made to use these new tests to determine whether the patient has celiac sprue. Which of the following represents the most appropriate testing strategy?

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: After careful analysis of the data from the 2 tables, a decision is made to use these new tests to determine whether the patient has celiac sprue.  Which of the following represents the most appropriate testing strategy?

Quizplus · Accepted Answer

Explanation: Screening tests should be used in an orderly and efficient manner. Highly sensitive tests are most appropriate for screening as they are the most likely to detect a disease and the least likely to give false-negative results. Given a test with high sensitivity, a negative result would help to rule out a diagnosis (SnNout). This assures the provider ordering the test that the probability of missing the diagnosis is low. After obtaining a positive result from the more sensitive test, a more specific test is ordered. Highly specific tests have a low rate of false positives. This means that most healthy patients have a negative test result (true negative). It is important for a confirmatory test to have high specificity. Given a test with high specificity, a positive result would help to rule in a diagnosis (SpPin). In this case, test Y has higher specificity and sensitivity; therefore, only this test is needed. (Choice A) Although the simultaneous use of 2 tests can sometimes increase the sensitivity and specificity that each test offers separately, there are insufficient data to support this possibility. A third table presenting information about the combined use of both tests is necessary. Educational objective: Highly sensitive tests are useful for screening; highly specific tests are useful for confirmation.

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