What level of sensitivity and specificity is acceptable?
Simply defined, sensitivity is the ability of a test to detect all true positives, whereas specificity is the ability of a test to detect only true positives. If a test is 100% sensitive, there will be no false negatives (no missed true positives). If a test is 100% specific, there will be no false positives (no missed true negatives). Discussion of sensitivity and specificity should occur together, since they frequently affect each other. Efforts to enhance sensitivity may decrease specificity, and efforts to enhance specificity may decrease sensitivity. If a test was 100% sensitive and 100% positive, it would be a perfect test. Unfortunately, there are very few perfect diagnostic tests in the world, and we have to settle for a certain level of acceptability. The acceptability level should be related to the specific question we are attempting to answer. For example, once a decision is made to eradicate a particular disease, regulatory officials frequently choose a highly sensitive tes
