Question | Answer |
Testing | done on those suspected on basis of signs, symptoms or family history to have disease |
Screening | done independent of signs, symptoms, or family history |
mass screening | low false negative rate; follow-ups identify true positives and true negatives, inexpensive |
Sensitivity | A/A+C percentage of affected actually affected |
Specificity | D/B+D percentage of unaffected who are unaffected |
To confirm results that may be false positives | confirm for genetic heterogeneity, biologic variation, error |
Biochemical assays | comprehensive in covering multiple mutations in one gene or several genes in a metabolic pathway with a common endpoint |
DNA mutation screens | Requires high frequency mutations with current technology |
A primary goal of population screening is | to predict with high accuracy which individuals in a group are at significant risk of developing or transmitting a disease. |
Once individuals at high risk for a disease are identified | confirmatory (diagnostic) tests are then performed to detect the screened-for disease with greater certainty |
A screening test only indicates | who in a given population is most likely to be at higher risk for developing a disease. |
A false positive occurs when a test | misidentifies individuals as being higher risk, when they are actually not at higher risk. |
A false negative occurs when | individuals with a higher risk for the disorder are not identified by the screening test. |
a diagnostic test is done following a positive screening test to determine | whether an individual has a disorder and thus rules out false positives. Diagnostic tests are typically more |
Disease registries | a valuable epidemiological resource that can be used to calculate incidence rates and risks, as well as to maintain surveillance and monitor trends in incidence and mortality. |