Thoughts of death and suicide reported by cancer patients who endorsed the "suicidal thoughts" item of the PHQ-9 during routine screening for depression

Background: Patients with serious medical illnesses, such as cancer, are at increased risk of suicide but are also often facing death. The Patient Health Questionnaire-9 (PHQ-9) is widely used to screen patients for depression. It includes an item that asks about thoughts of death and hurting yourself (Item-9).

Objective: To describe the nature of thoughts of death and suicide reported in clinical interviews carried out to further assess suicidal ideation of cancer outpatients who had endorsed the "suicidal thoughts item" (Item-9) of the PHQ-9 during routine depression screening.

Method: Secondary analysis of anonymized service data (with ethical approval) derived from the routine clinical administration of self-report questionnaires and telephone interviews to outpatients attending a Cancer Centre in the UK.

Results: Complete data were available on 330/463 (71%) of patients who had endorsed Item-9. In a subsequent structured telephone interview, approximately one-third of these patients denied any thoughts that they would be better off dead, another third acknowledged having thoughts that they would be better off dead, but not of suicide, and the remaining third reported clear thoughts of committing suicide.

Conclusion: Only one-third of cancer outpatients who endorse the "suicidal thoughts item" of the PHQ-9 report suicidal thoughts at a subsequent interview. Services planning to set up depression screening with the PHQ-9 need to carefully consider the relative benefits and burden to their service and patients of including Item-9 and interviewing all those who endorse it.