The prevalence of deliberate self-harm (DSH) is high in young adults. However, few studies have examined risk in this specific age group. We, therefore, examined the relative influence and interactive nature of a wide range of potential sociodemographic and sick leave related risk factors in young adults, aged 18-35 years, using Norwegian register data.
All subjects with at least one episode of hospital presentation for DSH registered in the Norwegian Patient Register during the period 2008-2013 were compared with age, gender and date matched population controls using a nested case-control design. The relative influence of factors and their interactions were assessed using conditional logistic regression and recursive partitioning models.
9 873 study cases were compared to 186 092 controls. Socioeconomic status, marital status, sick leave and several demographic factors influenced risk for DSH. Specifically, low education (OR 7.44, 95% CI 6.82-8.12), current sick leave due to psychiatric disorders (OR 18.25, 95% CI 14.97-22.25) and being previously married (OR 3.83, 95% CI 3.37-4.36) showed the highest effect sizes. Importantly, there was an interaction between education and sick leave, where those with either low education and no sick leave (OR 13.33, 95% CI 11.66-15.23) or high education and sick leave (OR 18. 87, 95% CI 17.41-24.21) were the subgroups at highest risk.
DSH in young adults is associated with multiple sociodemographic and health disadvantages. Importantly, the two high-risk subgroups imply different pathways of risk and a need for differentiated preventative efforts.