Background and Objectives:
Self-injurious thoughts and behaviors (sitb) can be divided in suicidal and non-suicidal self-injuries (nssis). In italy, there is a lack of longitudinal epidemiological data on trends in admissions of adolescents to eds for nssis. This study aims to describe the frequency and reason of access to ed among the population between the ages of 10 and 19 years in piedmont, and to identify risk groups by age and geographical areas.

Methods:
A retrospective cross-sectional study was conducted on medical records (gathered from the ministerial database of health information) of patients aged between 10 and 19 years, accessing eds in the piedmont region. All eds’ accesses from january 2011-september 2021 were included, all potential nssis (at triage and through icd9 codes) were selected. Gender and age proportion of eds’ hospitalization due to nssi was calculated for 100 thousand accesses each year, and overall methods, severity and geographical risk were described.

Results:
A total of 1,414,096 ed visits were analyzed, with an nssi ratio of 46.8 cases per 100.000 ed admissions. The overall ratio from 2011 to 2021 increased from 42.6 to 66.9 with a 57% increase. Nssi were more frequent in girls, with a significantly higher risk of admission (or=1.18; 95%ci 1.01-1.38), except in 2013 and 2015. The 15-19 years old compared with 10-14 years old, showed a greater odds ratio of 1.44 (1.15-1.80). The analysis carried out on urban vs peri-urban vs suburban areas showed gradually increasing adjusted risk: 1 vs 1.26 (0.97-1.64) vs 2.19 (1.62-2.97).

Conclusion:
Nssis represent a public health issue and deserves specific attention due to the dramatic increase registered in the last seven years. The nssis cases which require ed access are the most severe cases, the remaining mild or moderate portion of this phenomenon is likely to be underestimated by 10-20 times.