A recent study used data from the Irish National Registry of Deliberate Self-Harm to compare hospital-treated self-cutting patients and those presenting with intentional overdose, looking in particular at gender differences, patients’ characteristics and the outcomes associated with each method of deliberate self-harm.1 The definition of self-harm used was that of the WHO/EURO Multicentre Study, which includes all intentionally-initiated drug overdoses, poisoning or self-injurious behaviour regardless of suicidal intent. 

The study examined data on 42,585 persons who presented to emergency departments in Ireland between 1 January 2003 and 31 December 2009 with a first self-harm episode resulting from self-cutting, intentional overdose or a combination of both. Of these, 24,775 (58.2%) were women.   The highest number of presentations were as a result of overdose only (34,445), followed by self-cutting only (6,398) and finally a combination of overdose and self-cutting (1,742). 

Significant differences were found between presentations with overdose only and those with self-cutting only. Gender was significantly associated with method of self-harm: 21% of male presentations were for self-cutting compared to 10% of female presentations. Place of residence was also significant, with males and females living in cities being over-represented among presentations involving self-cutting. Living circumstances were also significant, with those of no fixed abode being over-represented among self-cutting presentations. 

Among those presenting with combined self-cutting and overdose, males and females were more evenly represented (4.5% vs 3.8%). Males and females living in cities were also both over-represented among presentations involving self-cutting and overdose. Use of alcohol was significantly associated with overdose by both males and females. Presentations for self-cutting combined with overdose were less likely between 9am and 5pm, and more likely at weekends than cases of overdose only. Repetition was also significantly more likely among those presenting with self-cutting. 

Multinomial logistic regression was used to identify factors independently associated with method of self-harm. When compared with overdose only, factors independently associated with self-cutting among both males and females were living in a city, being of no fixed abode or living in an inpatient or custodial setting, presenting outside the hours of 9am to 5pm or at weekends, no alcohol involvement and repetition within 12 months. In addition, being aged over 45 years for men and over 55 years for women was significant. Factors independently associated with combined overdose and self-cutting for men were being aged over 35 year, living in a city, presenting at the weekend and repeating within 30 days; for women, significant factors were being over 45 years of age, residing in a city, alcohol involvement and repeating within 12 months. 

The article concluded that the demographic and clinical differences between those presenting with different methods of self-harm have implications for choice of intervention. In particular, the association between self-cutting and repetition means that adequate follow-up and support need to be put in place. Moreover, services need to be available outside regular working hours.

1. Arensman E, Larkin C et al. (2014) Factors associated with self-cutting as a method of self-harm: findings from the Irish National Registry of Deliberate Self-Harm. European Journal of Public Health 24(2): 292–297. www.drugsandalcohol.ie/21823