Validity of the Brief Symptom Inventory-18 (BSI-18) for Identifying Depression and Anxiety in Young Adult Cancer Survivors: Comparison With a Structured Clinical Diagnostic Interview

The Brief Symptom Inventory-18 (BSI-18) is widely used to assess psychological symptoms in cancer survivors, but the validity of conventional BSI-18 cut-off scores in this population has been questioned. This study assessed the accuracy of the BSI-18 for identifying significant anxiety and depression in young adult cancer survivors (YACS), by comparing it with a "gold standard" diagnostic interview measure. Two hundred fifty YACS, age 18-40 completed the BSI-18 and the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders (DSM-IV; SCID) interview assessing anxiety and depressive disorders. BSI-18 results were compared with SCID criteria using receiver operating characteristics (ROC) analyses. Forty four participants (17.7%) met criteria for >= 1 SCID diagnoses, and an additional 20 (8.0%) met criteria for clinically significant SCID symptoms without a diagnosis. General concordance between the BSI-18 GSI scale and SCID diagnosis was good (AUC = 0.848), but the 2 most widely used BSI-18 case rules failed to identify a majority of survivors with SCID diagnoses, and no alternative BSI-18 cut-off scores met study criteria for clinical screening. Analyses aimed at identifying survivors with significant SCID symptoms or a SCID diagnosis had similar results, as did analyses examining depression and anxiety separately. The BSI-18 shows good overall concordance with a psychiatric interview, but recommended cut-off scores fail to identify a majority of YACS with psychiatric diagnosis. Clinicians should not rely on the BSI-18 alone as a screening measure for YACS. Alternative BSI-18 scoring algorithms optimized for detecting psychiatric symptoms in YACS may be an important step to address this limitation.