Sensitivity and Specificity

A screening program for tuberculosis in a high-prevalence urban slum uses sputum smear microscopy as the initial test. Smear microscopy has a sensitivity of 60% and specificity of 98% for detecting TB. Among individuals with a positive smear result, which investigation should be performed to confirm TB diagnosis with the highest diagnostic certainty?

A diagnostic test for tuberculosis (TB) has a sensitivity of 95% and specificity of 98%. In a high-burden TB setting in Mumbai where the pre-test probability of active TB is 20%, a patient tests positive. Which of the following is the most appropriate next step?

A diagnostic test for tuberculosis has a sensitivity of 95% and specificity of 85%. A competing test has a sensitivity of 80% and specificity of 95%. In a low-prevalence population (1% disease prevalence), which feature best distinguishes the clinical utility of these two tests?

A screening program for gestational diabetes mellitus (GDM) is being evaluated in a cohort of 500 pregnant women from Mumbai. A fasting blood glucose (FBG) test is compared against the oral glucose tolerance test (OGTT), which is the gold standard. The results are: - True positives: 72 - False positives: 48 - True negatives: 360 - False negatives: 20 A clinician interprets a negative FBG test as reassuring and discharges the patient without further testing. Based on the diagnostic accuracy of this test, which statement best reflects the clinical implication of this interpretation?

A diagnostic test for tuberculosis has a sensitivity of 95% and specificity of 85%. A competing test has a sensitivity of 80% and specificity of 98%. In a low-prevalence setting (1% disease prevalence), which feature best discriminates the clinical utility of these two tests?