Self-harm and suicide ideation presenters to hospital in Northern Ireland: a registry-based study

Abstract

BackgroundSuicidal behaviour is often described as a continuum, ranging from thoughts of suicide to engaging in self-harm or completing suicide. However, few studies have focused on people with suicidal ideation as a patient group. The aim of this study was to describe presentations to hospital following self-harm and suicidal ideation and to examine patterns of repetition. MethodsPresentations made to all 12 hospital emergency departments in Northern Ireland following self-harm and suicidal ideation between April 1, 2012, and March 31, 2017, were recorded by the Northern Ireland Self-harm Registry. Person-based rates per 100 000 were calculated using national population estimates. A Kaplan-Meier analysis was performed to examine patterns of repetition after self-harm and ideation and to calculate time between repeat events. The Northern Ireland Self-harm Registry has received ethics approval from the Office for Research Ethics in Northern Ireland. Findings22 910 individuals presented to hospital with self-harm and 10 473 with suicidal ideation. Although the rate of self-harm was more than twice the rate of suicidal ideation (345 per 100 000 vs 149), the profile of presenters was similar in age (mean 35 years, SD 14·7), time of arrival, and involvement of alcohol (n=13 373, 46·3%). There were almost equal numbers of male (n=17 896, 54%) and female (n=15 487, 46%) self-harm presenters, but most presenters with suicidal ideation were men and boys (n=6585, 63%). Repeat hospital presentation following an index episode was more common after suicidal ideation (2800 [36%] of 7800) than self-harm (6730 [32%] of 21 026) primarily because 943 (12%) of those presenting with suicidal ideation made a subsequent self-harm presentation whereas only 839 (4%) of those with an index self-harm presentation re-presented with suicidal ideation. Time to repetition was similar after self-harm and ideation: after 91 days, a quarter of presentations were followed by a repeat episode with the same outcome. InterpretationOur findings indicate that hospital presenters with suicidal ideation are at high risk of future suicidal behaviour. However, routine surveillance systems for suicidal behaviour do not usually record presentations involving suicidal ideation and clinical guidelines might not specifically address suicidal ideation. We contend that the transition from ideation to suicidal behaviour is important to consider and research could inform effective screening and early intervention measures. FundingPublic Health Agency, Northern Ireland.