AIDS Testing

Laboratory tests can be valuable aids in making a diagnosis, but, as screening tools for detecting hidden disease in asymptomatic individuals, their usefulness is limited. The value of a test as a diagnostic aid depends on its sensitivity and specificity. Sensitivity is the measure of the percentage of individuals with the disease who have a positive test result (i.e., people with the disease who are correctly identified by the procedure), and specificity is the …

…many as 18 or more tests can be performed for what it previously cost to carry out three or four individual tests. A panel of chemical tests for blood and urine have become routine components of the basic medical workup. A disadvantage of this strategy is that each test produces some false-positive results and requires additional tests to rule out these diseases. The trend is reversing to perform only those tests most likely to be cost-effective.