A 90% sensitivity means that 90% of the diseased people screened by the test will give a "true positive" result and remaining 10% a "false negative" result.> Sensitivity has been defined as the ability of a test to identify correctly all those who have the disease, that is "true positive".> Sensitivity: the ability of a test to identify correctly all those who have the disease, i.e. true positive ... a/a + c x 100> Specificity: The ability of a test to identify correctly those who do not have the disease i.e. true negative ...d/(b+d) x 100">