Risk of Self-Harm in Patients with Kleptomania: A Population-Based Cohort Study

Background: This study investigated whether individuals with kleptomania (KTM) are at higher risk of engaging in self-harm behaviors than individuals without KTM. Methods: In this matched cohort study, we analyzed the electronic health records of all patients admitted, for any indication, to public hospitals in Hong Kong between 1 January 1993 and 31 December 2022. We selected a KTM cohort consisting of 152 patients and a comparison cohort comprising 152 subjects. Participants were observed until they received a self-harm diagnosis, died from other causes, or reached the end of 2023, whichever occurred first. The Cox proportional hazards regression model was used to calculate the self-harm risk since KTM onset. Results: Over a 30-year study period, the number of individuals who engaged in self-harm in the KTM and comparison groups was ten (6.6%) and eight (5.3%), respectively. Both groups showed similar proportions of individuals who inflicted self-harm (χ2 = 0.49, p = 0.834). The self-harm incidence was 48.4 and 44.5 per 10,000 person-years in the KTM and comparison groups, respectively. The adjusted hazard ratio for self-harm in the KTM group was 0.49 (95% confidence interval, 0.16–1.48) relative to the comparison group. Conclusions: KTM is not associated with an increased self-harm risk. Future studies should replicate our findings and further delineate any distinct risk factors for self-harm in these patients.