Prison inmates have high frequencies of psychiatric disorders. Most prisons have little health-personnel resources, and methods to help focus resources towards those with serious health-care needs would be useful. The Global Symptom Index (GSI) of the Symptom Check List-90 (SCL-90) has performed well in other populations.
Prisoners at Kristiansand County Prison, Norway were asked to participate in the study, and 187 of 206 (91%) consented. All filled in the SCL-90 during the first four days of incarceration, and were examined clinically by a psychiatrist.
Clinical examination revealed 40 persons with psychiatric disorder. Of these, 37 had a GSI score > or = 1. There were three false negatives and two false positives. Based on various cut-off levels for the GSI, we found a GSI cut-off value at 1.5 to perform best with sensitivity = 0.78, specificity = 0.87, and Number Needed to Diagnose = 1.55.
SCL-90 performs well as a screening instrument for psychiatric disorders among prison inmates.