Health screening.
A test for a particular disease which is given to people who have no symptoms in order to identify how many of them have that disease or are showing early signs of it.
Tests given to see if someone has certain characteristics, especially problems. Among the common types are genetic screening tests, seeking to identify possible birth defects or health problems before or during pregnancy; neonatal screening tests, which try to identify medical problems so that they can be treated before doing harm to the developing infant; and developmental screening tests, used in preschool and early school years to identify problems that may adversely affect learning.
A simple test carried out on a large number of apparently healthy people to separate those who probably have a specified disease from those who do not. Examples are mass X-rays and cervical smears. Limitations depend on the severity and frequency distribution of the disease and the efficiency and availability of treatment. Other factors to be taken into account are the safety, convenience, cost, and sensitivity of the test.
Testing a population of apparently healthy people to identify those who may have treatable disease. Screening can be of a whole population for example all newborn babies are screened for developmental dislocation of the hip. Alternatively, screening can be selective, choosing a group of people known to be more at risk, perhaps because of their age. For example, elderly adults may be screened for colorectal cancer or abdominal aortic aneurysm. Screening tests are not designed to diagnose individual persons, but rather to divide a population into a large number at low risk and a small number at high risk of a condition. This allows clinicians to concentrate on a sub-section of the population. All screening tests produce false negative and false positive results, a problem often misunderstood by those at the receiving end, so they often lead to further confirmatory tests being needed before a firm diagnosis can be made. Factors to be assessed when planning screening procedures include the severity, frequency and distribution of the disease, and the availability and effectiveness of treatment. Convenience, safety, sensitivity of the test and cost should also be assessed.