Scores in the various cut-off zones determine whether the youth is a “critical case,” meaning that some action needs to be taken. The decision rule defining a critical case is determined as a matter of policy by the juvenile justice agency using the tool. [The MAYSI-2 Manual or the MAYSI-2 Helpdesk can provide guidance in forming that policy.] Here are examples of two typical combinations of scores defining a critical case:
Research has indicated that Definition A will identify about 18-22% of youth entering the facility as a “critical case.” Definition B will identify about 30-35% of youth as a critical case.
All screening tools produce some false positives (wrongly identified as having high mental health needs) and false negatives (having high mental health needs but wrongly identified as not having them). These will vary depending on the decision rule that is used. For example, using Definition A above, almost all youth meeting the definition will truly have high mental health needs, but some youth with high needs will be “missed.” Using Definition B, fewer will be “missed,” but only some of the youth meeting the definition actually will have high mental health needs.