An EMS-Based Crisis Response Model for Mental Health-Related EMS Calls: A Quasi-Experimental Study

The Behavioral Health Emergency Assistance Response Division (B-HEARD) program is an emergency medical services (EMS)-based alternative to police-led responses for nonviolent mental health crises in New York City. This study aimed to examine B-HEARD's effects on nonviolent mental health-related EMS call rates.

Data from the EMS Incident Dispatch Data file (January 2019-December 2024) were analyzed. The sample included 76 New York Police Department precincts, of which 31 adopted B-HEARD during the study period; the remaining 45 precincts did not adopt the program. A staggered-adoption, difference-in-differences design was used to compare monthly precinct-level rates of nonviolent mental health-related EMS calls between precincts that adopted B-HEARD and those that did not. Estimates were disaggregated by implementation wave and time since adoption.

Estimated effects were heterogeneous over time and across implementation waves. When aggregated by implementation wave, early-adopting precincts did not show statistically significant changes. By contrast, statistically significant reductions in call rate were observed among B-HEARD-adopting precincts in March 2023. When aggregated by calendar month, statistically significant call-rate reductions were concentrated in certain months during 2024. Dynamic event-time estimates suggested that, when present, reductions emerged approximately 1 year after program implementation.

The findings suggest that EMS-based, nonpolice crisis response programs may reduce nonviolent mental health-related EMS calls under specific operational and contextual conditions. The heterogeneous and delayed effects observed provide a benchmark for future evaluations aimed at identifying when and where these models translate into measurable, system-level change.