Which term describes the percentage of individuals who do not have a disease and test negative?

The percentage of individuals who do not have a disease and test negative is referred to as specificity. Specificity is a crucial metric in diagnostic tests, as it measures the test's ability to correctly identify those without the disease, thus reducing false-positive results.

When a test is highly specific, it means that when it indicates a negative result, it is very likely that the individual truly does not have the disease in question. For instance, if a diagnostic test has a specificity of 90%, it means that 90% of healthy individuals will correctly receive a negative result, while 10% may falsely test positive despite not having the disease.

In contrast, sensitivity measures the percentage of true positives, which indicates how well a test can identify individuals who do have the disease. Efficiency is not a standard term used in this context, and positive predictive value (PPV) refers to the likelihood that individuals with a positive test actually have the disease, rather than focusing on those who test negative.

Thus, the correct term that encapsulates the concept of individuals without a disease who receive a negative test result is specificity.