The Progression of Lethality Across Multiple Suicide Attempts: A Systematic Review.

Objective: Suicide is a major global public health concern. While some progress has been made in understanding risk factors for suicidal behavior, other relevant questions have received less attention. One such question relates to the longitudinal course of suicidal behavior amongst individuals with multiple suicide attempts. This systematic review investigated whether there is an increase in the lethality across multiple suicide attempts.

Method: This systematic review followed PRISMA 2020 reporting guidelines. A literature search was conducted in MEDLINE, Embase and PsycINFO electronic databases from inception to August 2023 to identify studies with key terms related to multiple suicide attempts and lethality. The review included longitudinal studies with data on multiple suicide attempts, and any rating of their lethality. Covidence was used to guide the screening and extraction process. A narrative synthesis approach was used to descriptively summarize included studies.

Results: After identifying 828 unique abstracts for screening, 11 studies were included for narrative synthesis. Suicide attempt assessment methods and definitions were heterogenous, often indirectly inferring lethality based on suicide attempt method. Individuals with repeat attempts may be more likely to continue using the same method.

Conclusions: There was no evidence to support increasing lethality across repeat suicide attempts. However, this should be interpreted along with the fact that the evidence base is scarce, heterogenous, and methodologically limited.