What do ‘positive result’ and ‘negative result’ mean?
A positive screening result suggests that it is more likely that a child has one of the screened conditions. For example, if a baby screens positive for PKU, it means that he or she is very likely, or is presumed to have PKU. A positive screening result indicates that further diagnostic tests are needed to confirm whether or not the child is affected. We cannot say whether a child is affected by the condition until these tests are undertaken and the result confirmed. A negative screening result suggests that it is unlikely that the child has any of the screened conditions. Under these circumstances further diagnostic tests are not needed. It is important to remember that screening is not 100% certain and a child with a negative screening result may later turn out to have the condition, while conversely, a child with a positive result may turn out not to have it.
