The incidence and repetition of hospital-treated deliberate self harm: findings from the world's first national registry

Abstract

Background: Suicide is a significant public health issue with almost one million people dying by suicide each year worldwide. Deliberate self harm (DSH) is the single most important risk factor for suicide yet few countries have reliable data on DSH. We developed a national DSH registry in the Republic of Ireland to establish the incidence of hospital-treated DSH at national level and the spectrum and pattern of presentations with DSH and repetition.

Methods and findings: Between 2003 and 2009, the Irish National Registry of Deliberate Self Harm collected data on DSH presentations to all 40 hospital emergency departments in the country. Data were collected by trained data registration officers using standard methods of case ascertainment and definition. The Registry recorded 75,119 DSH presentations involving 48,206 individuals. The total incidence rate fell from 209 (95% CI: 205-213) per 100,000 in 2003 to 184 (95% CI: 180-189) per 100,000 in 2006 and increased again to 209 (95% CI: 204-213) per 100,000 in 2009. The most notable annual changes were successive 10% increases in the male rate in 2008 and 2009. There was significant variation by age with peak rates in women in the 15-19 year age group (620 (95% CI: 605-636) per 100,000), and in men in the 20-24 age group (427 (95% CI: 416-439) per 100,000). Repetition rates varied significantly by age, method of self harm and number of previous episodes.

Conclusions: Population-based data on hospital-treated DSH represent an important index of the burden of mental illness and suicide risk in the community. The increased DSH rate in Irish men in 2008 and 2009 coincided with the advent of the economic recession in Ireland. The findings underline the need for developing effective interventions to reduce DSH repetition rates as a key priority for health systems.

Figure 1. Incidence of hospital-treated deliberate self harm by five-year age-sex group (A) and by single year of age for 10–24 year-olds (B).

(A) The annual rate per 100,000 population of male and female persons presenting to hospital as a result of deliberate self harm is shown by five-year age group with error bars representing the 95% confidence interval around the rate. (B) The annual rate per 100,000 population of male and female persons presenting to hospital as a result of deliberate self harm is shown by single year of age for 10–24 year-olds with error bars representing the 95% confidence interval around the rate.

Figure 2. Method of deliberate self harm (DSH) involved in male (A) and female (B) presentations to hospital in Ireland.

The areas illustrated in the charts represent the percentage of male and female deliberate self harm presentations involving different methods of self harm. Variation in the areas across the X-axis illustrates the variation in the method of self harm used by age.

Figure 3. Kaplan-Meier failure curves showing the cumulative probability of a repeated deliberate self harm (DSH) presentation.

The curves illustrate the cumulative probability of a repeated deliberate self harm (DSH) presentation to hospital in the twelve month period after an index DSH presentation. Variation in the probability of a repeated DSH presentation is shown by age group (A), by method of DSH (B) and by number of previous DSH presentations.