Paediatric suspected non-accidental or intentional self-harm injuries diagnosed after an emergency call: a national population-based cohort study from Denmark

Background Recognition of a non-accidental or intentional self-harm injury by emergency clinicians is essential to help prevent further physical and mental morbidity. The study objectives were to calculate the probability of paediatric suspected non-accidental or intentional self-harm injuries after an emergency call and to investigate the mechanisms of injury and any involvement of legal or social authorities noted by emergency medical services (EMS). Methods Nationwide population-based cohort study in Denmark from 1 January 2016 to 31 December 2023, including children ≤15 years for whom an emergency call had been made and who received a diagnosis of a suspected non-accidental or intentional self-harm injury by a hospital physician. Data were obtained from national hospital registers and from prehospital patient medical records. Injury probability after an emergency call was calculated stratified by sex. Results In hospital registers, the incidence of suspected non-accidental or intentional self-harm injuries was 34 per 100 000 children per year and among 138 599 paediatric EMS calls, 0.52% (95% CI 0.48% to 0.56%) resulted in such a diagnosis. Subgroups were ‘Asphyxiation’ (2.5%), ‘Maltreatment’ (15.1%), ‘Assault’ (31.2%), ‘Sexual abuse’ (5.9%), ‘Intentional self-harm’ (28.7%) and ‘>1 of the above categories’ (16.6%). Children aged 12–15 years had a higher probability of these injuries, both in males and females. In a sensitivity analysis excluding ‘Assault’ and ‘Intentional self-harm’, the probability increased markedly for males <1 year. All-cause mortality was 1.4% (n=10, 95% CI 0.7% to 2.6%). EMS had involved police in 17.6% and social authorities in 2.0%. Conclusion Of all the children diagnosed with a suspected non-accidental or intentional self-harm injury in a hospital in Denmark, only a small proportion had been brought to the hospital by the EMS. Two-thirds of the injuries had been inflicted by another person, while a third was due to intentional self-harm. Involvement of legal or social authorities by EMS was uncommon.