The association between the Police, Ambulance, Clinician Early Response model and involuntary detentions of people living with mental illness: A retrospective observational study

Background: Involuntary detention is a common method of enforcing mental health assessment and treatment; however, it is associated with poor patient outcomes and high emergency service and hospital demand. Aim: To examine the association between (1) Police, Ambulance, Clinician, Early Response (PACER) model, (2) police or (3) ambulance response and rates of involuntary detention of mentally ill people. Methods: A retrospective observational study using routine administrative data in an Australian City, over a 12-month period (2019–2020). Results: Over a 12-month period, 8577 people received crisis mental health intervention in the study setting. We observed an 18% increase in the relative risk of being involuntarily detained by police, and a 640% increase in the relative risk of being detained by ambulance. The PACER team detained 10% of their total presentations, as compared with 12% by police and 74% by ambulance. Involuntary detentions enacted by PACER were more likely to convert to a post-detention hospitalization (72%), when compared with police (27%) and ambulance (17%). Discussion: PACER was associated with lower rates of involuntary detention and higher rates of post-detention hospitalization when compared to police and ambulance response. Implications for Practice: PACER cohort experience more positive outcomes than with police or ambulance cohorts.