Dual diagnosis and mechanical restraint – a register based study of 31,793 patients and 6562 episodes of mechanical restraint in the Capital region of Denmark from 2010–2014

OBJECTIVE: To investigate whether patients with dual diagnosis have a higher risk of being mechanical restraint compared to patients with only psychiatric diagnoses. METHODS: Data on all patients admitted to a psychiatric ward from 2010-2014 in the Capital Region of Denmark was linked with information from the register of coercive measures. Patients were based on diagnosis divided into six groups. The three main patient groups were: only psychiatric diagnosis defined as all ICD-10 F-diagnosis except F10-F19, dual diagnosis (co-occurrence of diagnoses of harmful use or dependency and psychiatric diagnoses) and only other substance use diagnosis (i.e. other than harmful use or dependency). The risk of mechanical restraint was investigated by analyzing all first-time admissions in the period using Cox-proportional hazard models. RESULTS: In the crude rates patients with dual diagnosis were more often mechanically restrained compared to patients with only psychiatric diagnoses or only other substance use diagnoses. However, this was attenuated when the characteristics of patients were accounted for. Patients with only other substance related diagnoses had the highest risk of being mechanically restrained. CONCLUSION: When preventing mechanical restraint, the focus should be on actual use of substances or withdrawal effects and not on the dual diagnoses patients in them-self.