The utility of PHQ-9 and CGI-S in measurement-based care for predicting suicidal ideation and behaviors

Measurement-based care (MBC) has emerged as an effective strategy for improving outcomes in patients with mood disorders. Suicide is a particularly devastating outcome of mood disorders. Using data from a new MBC program from the National Network of Depression Centers (NNDC), we examined whether capturing a patient-rated symptom measure, the patient health questionnaire (PHQ-9), along with a provider-rated global functioning measure, the clinical global impression scale (CGI-S), improves identification of patients at risk of suicide over using either measure alone.

A total of 126 adults with mood disorders from nine sites in the NNDC completed the PHQ-9 and CGI-S and had at least one subsequent visit where they completed the Columbia-suicide severity rating scale (C-SSRS). The PHQ-9 (≥10) and CGI-S (≥4) were dichotomized at commonly accepted severity thresholds. Associations of the PHQ-9 and CGI-S with suicidal ideation or behavior were examined using Firth's logistic regression to accommodate small samples while controlling for age, sex, race, and diagnosis.

Patients who scored higher on only the PHQ-9 or CGI-S were not significantly more likely to experience subsequent suicidal ideation or behaviors. However, patients who scored higher on both the PHQ-9 and CGI-S were significantly more likely to experience suicidal ideation (OR = 4.70, p = 0.0005) and suicidal behaviors (OR = 25.38, p = 0.0003).

Information from both patient and clinician-rated measures was better able to identify patients with mood disorders at risk for suicidal ideation and behaviors. Using both together may help reduce the risk of suicide by identifying those patients at greatest risk and allowing for more targeted interventions.