All of the following are true for a screeing test except-
Screening tests do not form the basis for treatment as a specific diagnostic test will need to be performed to confirm the diagnosis suggested by a screening test in order to start a specific treatment.
For example, in HIV infection screening is done by ELISA. If the ELISA comes to be positive, western blot is done to confirm the diagnosis before starting treatment.
Less accurate
Forms the basis for treatment
Test results are arbitrary
Less expensive