Rationale Very little is known about the association, if any, between suicide ideation, self-harm and completed suicide. Northern Ireland is unique in that it is the only country in the world to hold a registry of all presentations to Emergency Departments for suicide ideation. As NI has the highest suicide rate in the UK and Ireland it is vital to understand who is most at risk in order to target prevention strategies effectively. The aim of this study is to examine the characteristics of those individuals who present to Emergency Departments with suicide ideation and to explore the risk factors associated with subsequent suicide.

Data The Northern Ireland Registry of Self-Harm and Suicide Ideation contains information on all presentations to all Emergency Departments in NI for self-harm and suicide ideation. These data for the four years 2012–2015 were linked to centralised electronic data relating to primary care, social services and prescribed medication and mortality records.

Methods Descriptive analyses to explore the profile of those who present with suicide ideation and regression analyses to examine the likelihood of mortality post ideation after adjusting for a range of factors known to be associated with mental ill health.

Results The cohort consisted of all 1,483,435 individuals born or resident in NI from 1st January 1970 until 31st December 2015 (maximum age in 2015, 45 years). During the 4-year period 2012–2015, 3,644 (0.3%) individuals presented with suicide ideation and 1,719 (0.1%) individuals died by suicide. Ideation is more likely in men compared to women (OR=1.95, 95%CI 1.81,2.09) and in those aged 18–24 years. It is also associated with deprivation and with a history of being in care, with previous and current looked after children over 11 times more likely to present with suicide ideation compared to those not in care (OR=11.28, 95%CI 10.00,12.71). Of those who presented with ideation 1.13% subsequently died by suicide. After full adjustment, those who presented with suicide ideation were over 4 times more likely to die by suicide compared to those who did not (OR=4.52, 95%CI 3.29,6.21). Amongst suicide ideators there is no difference in likelihood of suicide based on age, gender or area of residence.

Further analysis is underway to explore which particular traits and characteristics of those who present with suicide ideation are most associated with risk of suicide and how this differs from those who self-harm in order in inform intervention targeting.