Police, ambulance and psychiatric co-response versus usual care for mental health and suicide emergency callouts: A quasi-experimental study.

Abstract

Mental health-related calls to emergency services made via 111 (New Zealand) or 000 (Australia) often represent critical junctures for the person in crisis. Traditionally, police, ambulance and mental health services work separately to manage such emergencies. Sequential agency responses may be protracted and cause escalation. This study tests multi-agency co-response aiming for more integrated, faster, safer and less coercive management of mental health crises. Immediate and 1-month outcomes of mental health emergency calls made to police and ambulance were compared according to whether they occurred on days with co-response availability. Outcomes measured included emergency department admission and waiting times, psychiatric admissions, compulsory treatment, use of force, detention in police cells and the time to resolution of the event. Relative risk estimates were constructed. A total 1273 eligible mental health emergency callouts occurred between March 2020 and March 2021 (38% coded 'mental health' emergencies, 48% suicide risk and 14% as 'other'), 881 on days with co-response availability and 392 on days without. Co-response interventions were resolved faster and were more likely to be community-based. Fewer than one-third (32%) led to emergency department admissions, compared with close to half (45%) on days without co-response (risk ratio: 0.7 [0.6, 0.8]). In the following month, the number of emergency department and mental health admissions reduced (p < 0.01 and 0.05, respectively). There were no statistically significant differences in use of force and few people were detained in police custody. Co-response intervention increased the likelihood of mental health crises being resolved in the community and reduced hospitalisations. Benefits were sustained at 1 month.