Suicidal Ideation Among Patients With Breast Cancer: A Comparison of Patient Health Questionnaire-9 Item 9 and Columbia-Suicide Severity Rating Scale.

BACKGROUND: The Columbia-Suicide Severity Rating Scale (C-SSRS) is the gold standard for assessing suicidal ideation, behavior, and risk. However, it is unclear whether the Patient Health Questionnaire-9 (PHQ-9) item 9 alone is sufficient for detecting suicidal ideation among patients with breast cancer. This study aimed to assess the validity of PHQ-9 item 9 compared to C-SSRS in female breast cancer patients undergoing psychiatric treatment. METHODS: In this study, we evaluated the validity of PHQ-9 item 9 compared to C-SSRS for identifying suicidal ideation among 176 female patients with breast cancer receiving psychiatric treatment, using self-reported questionnaires and leveraging demographic, clinical data, and statistical analyses to refine suicide risk assessment methods. RESULTS: Among 176 patients, 35.2% showed a positive response to PHQ-9 item 9, 41.0% and 17.0% of them showed a response indicating wish for death and active suicidal ideation based on C-SSRS, respectively. The areas under the ROC curves for wish for death and active suicidal ideation were 0.840 and 0.842, respectively, indicating good discriminatory power with an optimal cut-off of 1/3 for both criteria. CONCLUSION: Although PHQ-9 item 9 may have limited utility in detecting active suicidal ideation among patients with breast cancer, it may serve as a valuable screening tool for identifying those at risk of having thoughts of suicide accompanied by wish for death.