Improving suicide surveillance systems through the use of the Patient Health Questionnaire-9

Suicide is a major public health problem worldwide and continues to be one of the main causes of death. Implementing surveillance strategies for suicidal thoughts and behaviours would make it possible to identify individuals at high risk of ending their lives by suicide. While a universal screening would be controversial, the increasing use of the 9-item version of the Patient Health Questionnaire (PHQ-9) in different healthcare settings, such as primary care or hospital emergency departments, offers an opportunity for testing its performance for suicide surveillance. Beyond being a screening of depression, the PHQ-9 has shown merit as a marker of suicidal thinking, thoughts of self-harm, and suicide. Implementing systematic surveillance strategies for suicide in different healthcare settings including data from the PHQ-9 might be an effective way to improve case detection. This could help to enhance the identification of highest risk population groups and, consequently, to avoid potentially preventable suicides.