Background/Purpose: Depression is common in rheumatic diseases, including systemic sclerosis (SSc). In the general population, depression is associated with suicidal ideation, attempts and completion. The Patient Health Questionnare-9 (PHQ-9) is a self-administered and easily scored measure of depression symptoms that is increasingly used in medical settings. Item 9 of the PHQ-9 has been used in several studies, including with arthritis patients, to assess the prevalence of suicidal ideation. Item 9 asks patients “How often have you been bothered by thoughts that you would be better off dead or of hurting yourself in some way?” The item is ambiguous, however, because it includes both passive thoughts of death and more active ideas of self-harm. As a result, some researchers have advocated using the PHQ-8, which does not include Item 9. Thus, the objectives of this study were (1) to determine the proportion of SSc patients who responded anything other than “never” to Item 9 who endorsed active suicidal ideation in response to more direct questions during a structured clinical interview and (2) to assess the association between the PHQ-9 and the PHQ-8, which does not include Item 9.

Methods: Canadian Scleroderma Research Groups Registry patients were administered the PHQ-9 and the Composite International Diagnostic Interview (CIDI) depression module in a phone interview. Item 9 responses were compared to suicidal ideation and intent in the last year based on the CIDI. PHQ-8 scores were calculated by subtracting Item 9 scores. The association between the PHQ-9 and the PHQ-8 was computed using the Pearson correlation coefficient.

Results: Of 313 patients in the study, 30 (6.9%) screened positive for suicidal ideation on the Item 9. Of those, only 1 (3.3%) had thought about suicide in some detail as assessed by the CIDI at any time in the past year. No patients had an active suicide plan at the time of the interview. Correlation between PHQ-9 and PHQ-8 scores was r=0.998.

Conclusion:

Item 9 does not appear to be an effective suicide screen. There is currently no evidence that screening for suicidality would prevent suicidal behaviour. If researchers or clinicians do screen for suicidality, direct questions about suicide should be asked. The PHQ-8 may be a better option than the PHQ-9 for assessment of depressive symptoms in SSc patients given the high association with the PHQ-9 and the ambiguous nature of Item 9.

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/the-utility-of-the-patient-health-questionnaire-9-to-assess-suicide-risk-in-patients-with-systemic-sclerosis/