Screening childhood cancer survivors with the brief symptom inventory-18: classification agreement with the symptom checklist-90-revised

The Brief Symptom Inventory-18 (BSI-18) is an 18-item symptom checklist used as a brief distress screening in cancer and other medical patients. This study evaluated the validity of the BSI-18 in a sample of 221 adult survivors of childhood cancers ages 18-55 (median = 26). Validity of the BSI-18 was compared to the Symptom Checklist-90-Revised (SCL-90-R). Results indicated the BSI-18 scales had acceptable internal consistency (alpha >0.80) and were highly correlated with the corresponding SCL-90-R subscales (correlations from 0.88 to 0.94). When subjects were classified as case positive (significantly distressed) using the BSI-18 manual case-rule, classification agreement with the SCL-90-R was poor as evidenced by low sensitivity (41.78%). An alternative BSI-18 case-rule previously developed for cancer patients using the General Severity Index (GSI; GSI t-score >or=57) demonstrated better sensitivity (83.54%). ROC analysis indicated the BSI-18 had strong diagnostic utility relative to the SCL-90-R (AUC = 0.98) and several possible GSI cut-off scores were evaluated. The optimal cut-of score was a t-score >or=50 which had a sensitivity of 97.47% and a specificity of 85.21%. Results support use of the BSI-18 with adult survivors of childhood cancer but indicate an alternative case-rule must be used.