Abstract
Discussion
Sensitivity means that if the test is negative, then the condition is unlikely. Conversely, if a test is specific, positivity implies that the condition is present. The ideal test is both sensitive and specific.
Wilson—Jungner criteria for appraising the validity of a screening programme
The condition being screened for should be an important health problem.
The natural history of the condition should be well understood.
There should be a detectable early stage.
Treatment at an early stage should be of more benefit than at a later stage.
A suitable test should be devised for the early stage.
The test should be acceptable.
Intervals for repeating the test should be determined.
Adequate health service provision should be made for the extra clinical workload resulting from screening.
The risks, both physical and psychological, should be less than the benefits.
The costs should be balanced against the benefits.
In addition, the WHO criteria (2003) specify:
All other options for managing the condition should have been considered (for example, improving treatment and providing other services), to ensure that no more cost-effective intervention could be introduced or current interventions increased within the resources available