Injuries prior and subsequent to index poisoning with medication among adolescents: a national study based on Norwegian patient registry

BACKGROUND: Adolescents treated for self-poisoning with medication have a high prevalence of mental health problems and constitute a high-risk population for self-harm repetition. However, little is known about whether this population is also prone to injuries of other forms. METHODS: Data were extracted from the Norwegian Patient Registry to include all incidents of treated injuries in adolescents aged 10–19 years who were treated for self-poisoning with medication during 2008–2011. This longitudinal approach allowed for the inclusion of injuries of various forms both before and after the index poisoning with medication. Gender differences and associations of injuries with recorded deliberate self-harm or psychiatric comorbidity at index poisoning were analysed. Forms of injury and psychiatric illnesses were coded according to the ICD-10 system. RESULTS: 1497 adolescents treated for self-poisoning with medication were identified from the source database, including 1144 (76.4%) girls and 353 (23.6%) boys. For these 1497 adolescents a total of 2545 injury incidents were recorded in addition to the index poisoning incidents, consisting of 778 injury incidents taking place before the index poisoning and 1767 incidents taking place subsequently. Altogether 830 subjects (55.4%) had an injury treated either before or after the index poisoning. Injuries to the hand and wrist as well as injuries to the head, neck and throat were predominant in males. Females were more likely to repeat poisoning with medication, particularly those with psychiatric disorders. CONCLUSION: Adolescents treated for poisoning with medication represent a high-risk population prone to both prior and subsequent injuries of other forms, and should be assessed for suicidal intent and psychiatric illness.