Validation of brief screening tools for mental disorders among New Zealand prisoners

This study aimed to validate brief intake screens for serious mental illnesses among New Zealand male prisoners.

A prospective survey of consecutively admitted male remanded and sentenced prisoners was conducted across two New Zealand sites. Participants completed the Brief Jail Mental Health Screen (BJMHS) and the English Mental Health Screen (EMHS) upon prison admission. The validation standard, the Mini International Neuropsychiatric Interview (MINI), was completed for all positive screens and a random selection of negative screens.

A total of 1,292 brief screens and 530 MINI screens were completed. Fifty-one percent of the participants met MINI criteria for one of five targeted major mental disorders. In this study, the BJMHS performed with lower sensitivity, higher specificity, a lower false-positive rate, a significantly higher false-negative rate, and a much higher referral rate than in the validating U.S. study. And in this study the EMHS performed with lower sensitivity, less specificity, higher false-positive and false-negative rates, and a moderately higher overall referral rate than in the validating U.K. study. For the BJMHS and EMHS, the majority of false-negative cases involved a mood disorder and few involved psychosis.

Although the BJMHS and EMHS did not perform well in terms of screening for MINI diagnoses, they appeared to be good at identifying a core group of prisoners who are psychotic and most likely to require urgent or semi-urgent intervention by mental health services. The most favorable clinical outcomes were achieved by defining a positive screen as one in which either the EMHS or the BJMHS criteria were fulfilled.