Understanding Suicide Clusters Through Exploring Self-Harm Behaviors.

: There is little information about characteristics and long-term outcomes of individuals who self-harm during a suicide cluster. : To compare characteristics of individuals who self-harmed during a suicide cluster in South Wales (∼10 deaths between December 2007 and March 2008) with others who self-harmed prior to the cluster and to evaluate 10-year self-harm and mortality outcomes. : Using records from the hospital serving the catchment area of the suicide cluster, enhanced by national routinely collected linked data, we created the following two groups: individuals who self-harmed (a) during the suicide cluster and (b) 1 year before. We compared individuals' characteristics and performed logistic regression to compute odds ratios of 10-year self-harm and mortality outcomes. : Individuals who self-harmed during the cluster were less likely to be hospitalized or have a mental health history than those who self-harmed prior to the cluster. No significant group differences were found for 10-year self-harm outcomes, but all-cause mortality was higher for males. : Sample size was small, and data were lacking on psychological and social proximity to individuals who died during the suicide cluster. : Our findings highlight the importance of long-term healthcare follow-up of those who self-harm during a suicide cluster, particularly males.