Police,ambulance and mental-health clinician early response (PACER) models in Australia and New Zealand: a narrative review of emergency department impacts and consumer and service provider experiences

Rationale for the review

Traditional ED-centred crisis pathways place substantial strain on health and law-enforcement systems and do not consistently meet the needs of people experiencing acute psychological distress. Delays, crowding, and lack of specialist input at first contact can contribute to escalation, repeated presentations, and coercive interventions. These limitations have prompted increasing interest in collaborative, community-based responses prioritising early intervention, de-escalation, and continuity of care.

PACER models were developed to address these gaps by embedding MH clinicians within frontline response teams. This approach reflects recognition that ED-based pathways strain both hospital and policing services while often failing to meet consumer needs. ⁴ Australian analyses of ambulance mental-health presentations further highlight pressure on EDs and support the need for integrated, multidisciplinary crisis responses. ⁵

By providing on-scene clinical assessment, therapeutic de-escalation, and supported triage, PACER models aim to reduce unnecessary ED conveyance and promote safer, more person-centred care.

Policy and international context

The expansion of PACER models across Australian states and New Zealand’s Crisis Response Team (CRT) reflects growing policy relevance. However, published evaluations remain fragmented, with substantial variation in design, outcome measures, and scope. This limits the ability to draw coherent conclusions regarding effectiveness, implementation challenges, and provider and consumer experiences.

Internationally, crisis-response approaches such as the Memphis Crisis Intervention Team and the Los Angeles SMART model established structured partnerships between police and mental-health clinicians to improve on-scene assessment, de-escalation, and referral. ⁶ Australian and New Zealand adaptations added ambulance personnel, forming a tri-service response that reflects the clinical complexity of many crises, where physical illness, intoxication, injury, and behavioural disturbance often co-occur.

Early evaluations reported fewer ED transfers, improved inter-agency collaboration, and enhanced risk assessment.^7,8 However, models vary in leadership, scope, and configuration, with uneven service coverage. In New Zealand, the Wellington CRT reported that 75% of their cases were resolved in the community via GP or NGO referral. ⁹

Police frequently encounter people in mental-health crisis, often in high-risk situations. Between 1989 and 2013, 42% of Australians fatally shot by police had a diagnosed mental illness, with similar patterns reported in New Zealand.^9,10 These figures underscore the need for crisis models that prioritise early clinical assessment, de-escalation, and therapeutic engagement to improve outcomes. PACER reframes crisis response as a shared public health responsibility rather than a solely law-enforcement function.

Aim of the review

This review synthesises available evidence on PACER models in Australia and New Zealand, examining associations with emergency department presentations, provider experiences, and consumer experiences to assess acceptability and inform future service development.

Design

A narrative literature review was conducted to synthesise emerging evidence on PACER models in Australia and New Zealand. This approach was selected because the literature is characterised by heterogeneous designs, variable outcome measures, and a predominance of qualitative, mixed-methods, and service-level evaluations.

Although the PICO framework informed question formulation and thematic organisation, a formal PRISMA methodology was not applied due to the absence of consistent intervention definitions, standardised outcome measures, and comparable study designs. Narrative synthesis allowed integration of empirical findings with policy-relevant and contextual sources.

Search strategy

Electronic searches were conducted in PubMed, MEDLINE, PsycINFO, CINAHL, INFORMIT, and Google Scholar for literature published between 2007 and 2025. Search terms included combinations of ‘PACER’, ‘co-responder teams’, ‘street triage’, ‘police mental health’, ‘ambulance mental health’, and ‘emergency department mental-health presentations’, together with geographic identifiers (‘Australia’ and ‘New Zealand’). Reference lists were hand-searched, and relevant grey literature was included where it provided substantive information on implementation, outcomes, or stakeholder experience.

Study selection

The initial search identified 126 records. After removal of duplicates and screening for relevance, nine empirical studies met inclusion criteria, defined as primary research evaluating PACER implementation, outcomes, or consumer and service provider experiences. An additional 12 contextual and policy-relevant sources (e.g. government reports and service evaluations) were included to support interpretation. In total, 21 sources were synthesised.

Data extraction and synthesis

Data were extracted on study design, participant group, service configuration, and outcomes relevant to the review aims. An inductive thematic synthesis identified three domains: (1) impact on ED. presentations; (2) provider experience and inter-agency collaboration; and (3) consumer and broader stakeholder experience. These domains informed our results and discussion.

Theme 1 – impact on emergency-department presentations

Across included studies, PACER models were associated with reduced ED. conveyance and increased rates of on-scene resolution or referral to community-based services. Several evaluations attributed these outcomes to the presence of an embedded MH clinician which enabled more comprehensive on-scene assessment, and facilitated alternative care pathways that did not involve ED transfer.^6–8,11

Jurisdictional evaluations reported similar patterns. In Victoria, the NPACER model enabled ED diversion and improved transitions through emergency and acute care pathways. ¹⁰ In Queensland, the Cairns Co-Responder project reported reduced hospital conveyance. ¹¹ Evaluation of the A-PACER model found that a substantial proportion of crisis encounters was resolved in the community rather than requiring ED transfer. ¹² In New Zealand, Wellington CRT outcomes were reported across both a quasi-experimental study and a separate evaluation report and described community resolution pathways and reduced ED utilisation on operating days.^9,13

Outcome measures varied considerably between studies and included changes in ED presentation, involuntary detention, and patterns of referral to primary care or non-government services.^9,13 Some studies also described qualitative changes in ED presentations when PACER conveyance occurred, including improved triage accuracy and more targeted referral pathways.^6–8

While some studies reported admission-related outcomes descriptively,^9,13 these were not examined as primary or systematically analysed endpoints. Few evaluations incorporated longitudinal follow-up beyond the index crisis episode. Several authors noted limitations in routinely collected data, including inconsistent documentation and reliance on service-level reporting rather than standardised outcome measures,^6,7,9,13 constraining direct comparison across jurisdictions.

Formal economic evaluations of PACER models were not identified. However, several studies descriptively reported indirect indicators of potential system efficiencies, including reduced ED conveyance, fewer repeat crisis callouts, and shorter on-scene resolution times.^7–9 These outcomes were described as reducing demand on EDs and decreasing police and ambulance downtime.

Theme 2 – provider perspectives: role clarity, decision-making, and inter-agency collaboration

Across included studies, PACER implementation was associated with changes in role clarity, decision-making, and inter-agency collaboration among frontline providers. Police officers described increased confidence when responding to mental health-related crises in the presence of an embedded MH clinician, particularly in situations involving suicidality, psychosis, or behavioural disturbance.^11,14,15 This was attributed to immediate access to specialist clinical expertise, rather than reliance on retrospective consultation or default ED conveyance.

Several evaluations reported that real-time clinical assessment influenced on-scene decision-making, with police and paramedics describing greater certainty regarding disposition options beyond ED transfer or involuntary detention.^{10,11,14–16} This enabled more nuanced judgments about risk, capacity, and appropriate referral pathways, including community-based care and direct linkage with MH services rather than hospitalisation.

MH clinicians embedded within PACER teams described that joint attendance facilitated earlier therapeutic engagement and more comprehensive assessment at the point of first contact.^10,14–16 They reported being able to intervene before behavioural escalation, establish rapport, and contribute to disposition decisions in real time, rather than receiving referrals after police decisions had already been made. Providers across disciplines described these processes as reshaping usual role boundaries and supporting shared responsibility for crisis management.

Several studies described shifts in crisis-management practices following PACER implementation, including greater emphasis on negotiated resolution and verbal de-escalation.^11,14,15 Police officers reported reduced reliance on containment-focused responses, while paramedics described improved coordination of physical and psychiatric risk assessment.^14,17

Shared risk management was identified as a defining feature of PACER responses, involving joint assessment, collaborative formulation, and negotiated decision-making between police, paramedics, and MH clinicians.^14–16 This approach modified traditional handover practices, with greater emphasis on shared responsibility and continuity of care rather than linear service transfer. Joint training initiatives were reported as supporting shared understanding of roles, de-escalation strategies, and inter-agency communication.^11,12,15,16 However, access to training and supervision varied between services. MH clinicians described high emotional load associated with repeated exposure to crisis work, alongside professional isolation when operating outside traditional clinical settings.^14,15 Limited access to structured clinical supervision and reflective practice opportunities was also reported. ¹⁵

Service providers identified potential value in incorporating peer workers and individuals with lived experience into PACER responses. These roles were described as potentially supporting engagement and assisting with de-escalation. ¹⁴

Access to PACER services beyond metropolitan areas was inconsistent. Barriers included large catchment areas, travel distances, limited after-hours coverage, and workforce shortages. ¹⁶ These constraints affected the feasibility of sustained PACER availability in regional and remote settings.

Some services used telehealth or secondary consultation models; however, connectivity issues and limited local workforce capacity reduced effectiveness. ¹⁶

Theme 3 – consumer perspectives: acceptability, trust, and perceived safety

Across included studies, consumers described PACER responses as more acceptable and less stigmatising than traditional police-only crisis responses. Several evaluations reported that the presence of an embedded MH clinician altered the tone of interactions, contributing to perceptions of greater empathy, legitimacy, and procedural fairness.^15,18,19 Crises were more often framed as health-related events rather than solely law-enforcement matters.

Consumers frequently reported feeling more listened to and understood, with joint police–clinician attendance facilitating more collaborative communication and shared decision-making.^18,19 MH clinicians were described as mediating between consumers and police, helping to translate clinical needs, contextualise behaviours, and reduce fear associated with police involvement.^15,19 Perceived safety was a central theme. Consumers described feeling safer when responses prioritised calm communication, de-escalation, and therapeutic engagement over containment or coercion.^15,18,19 Some contrasted PACER encounters with previous police-only responses, reporting reduced anxiety, lower perceived threat, and greater willingness to engage with services when an MH clinician was present.^18,19 Several studies reported that PACER supported greater trust in emergency and MH services. Respectful communication, transparent decision-making, and opportunities to express preferences were associated with more positive crisis experiences and greater acceptance of referrals and follow-up care.^18,19 Where ED. transfer did occur, consumers reported that prior on-scene clinical assessment supported clearer communication with hospital staff and more targeted triage. ⁹ Consumers valued alternatives to ED-based care, including referral to community services or primary care. ⁹

PACER was frequently perceived as less coercive than traditional emergency responses. Consumers described feeling less criminalised and more respected when MH clinicians were present.^18,20 Some valued avoidance of physical restraint, handcuffing, and prolonged ED waiting.^9,20

Carers and family members described PACER responses as more reassuring and coordinated than traditional emergency responses. On-scene MH clinicians facilitated explanation of risks, care options, and next steps, reducing uncertainty during acute episodes.^19,20

Community stakeholders, including general practitioners, NGOs, and community MH services, described PACER as improving referral quality and continuity of care, with clearer clinical context supporting more appropriate follow-up. ¹⁴

Cultural safety was emphasised in some evaluations. In New Zealand, consumers highlighted the inclusion of whānau, cultural advisors, and community networks as supporting trust, reducing alienation, and improving engagement among Māori and Pacific peoples. ¹⁵ However, some consumers remained ambivalent about police involvement, particularly regarding visibility, privacy, and the potential for misinterpretation in public settings. ¹⁹

Several evaluations noted that positive crisis responses did not always translate into continuity of care, with some consumers reporting difficulties accessing follow-up services.^14,15,19

Integration and safety outcomes

A consistent finding across the literature was the perceived value of PACER models in bridging health and law-enforcement systems at the point of crisis. On-scene clinical assessment was reported to support de-escalation and enable alternative resolution pathways, particularly in situations involving suicidality, psychosis, or behavioural disturbance. Police and paramedics described greater confidence and clarity when determining disposition options, including community-based referral rather than default ED transfer.^7–11

Several studies described shifts in frontline decision-making following PACER implementation, with greater emphasis on negotiated resolution, verbal de-escalation, and shared risk formulation. These changes were attributed to the availability of immediate MH clinical input, which supported more nuanced judgments about risk, capacity, and referral pathways. However, these findings were primarily derived from qualitative and service-level evaluations rather than controlled outcome studies and therefore should be interpreted cautiously.

From a systems perspective, these accounts suggest that PACER models may support perceived safety and more proportionate responses to mental-health crises. However, heterogeneity in outcome reporting and the absence of standardised safety indicators limit the strength of comparative conclusions.

System efficiency and cost

Evaluations suggested that diversion to community-based pathways reduced pressure on acute services, although these effects were not systematically measured. Claims regarding cost-effectiveness therefore remain inferential and should be interpreted cautiously. The absence of standardised economic metrics and controlled comparisons represents a key gap in the current evidence base.

Workforce and training

Several evaluations identified workforce-related challenges particularly for mental-health clinicians operating in high-intensity crisis environments. MH clinicians working outside traditional settings described high emotional load, repeated exposure to acute distress, professional isolation, as well as limited access to structured supervision14,15).

Police and paramedics emphasised the value of joint training, particularly for clarifying roles, communication processes, and de-escalation strategies.^11,12,15,16 These initiatives were described as supporting inter-agency collaboration and more coordinated responses. Access to training and supervision varied between services, possibly reflecting resourcing constraints. Workforce sustainability emerged as an important implementation issue unless training and supervision were improved and consistently available.

Empirical evaluation of peer worker involvement in PACER models remains limited in the existing literature. No included studies systematically examined the governance, safety implications, or clinical impact of peer roles within PACER teams.

Rural and remote access

Our findings suggest ongoing equity challenges in PACER distribution. There is inconsistent availability of PACER services beyond metropolitan areas and thus ED diversion and access to co-response is less likely to occur in rural areas.

Cultural safety and health-led reform

Few studies examined how cultural safety was operationalised and reporting remained largely descriptive. There was limited evaluation of how PACER models intersect with Indigenous governance frameworks or culturally specific care.

Consumer experience and recovery orientation

Consumers consistently reported PACER responses as more acceptable and less stigmatising than police-only crisis responses. MH clinician involvement was associated with calmer communication, greater perceived safety, and improved trust.^15,18,19 Where alternatives to ED transfer were available, consumers valued community-based pathways and reported relief at avoiding coercive practices and prolonged ED. waiting time.^9,20

Some consumers remained ambivalent about police involvement, particularly regarding visibility, privacy, and perceived risk of misinterpretation in public settings. ¹⁹ Several evaluations noted that positive crisis responses did not always translate into continuity of care, with some consumers reporting difficulty accessing follow-up services.^14,15,19

International comparisons

International evaluations report broadly similar patterns, including perceived reductions in arrests, improved inter-agency collaboration, and higher stakeholder satisfaction.^6,21 However, most studies are limited by small samples, short follow-up, and reliance on descriptive or self-reported outcomes.

Australian and New Zealand PACER models differ through their routine inclusion of ambulance services. Few studies have directly compared configurations, limiting inference regarding the influence of model design versus service context or evaluation methods.

Limitations of current evidence

The evidence base for PACER models in Australia and New Zealand remains limited. Most evaluations are pilot scale, use heterogeneous outcome measures, and have short follow-up periods, restricting comparability and inference about sustained impact. Few studies include control groups, standardised outcomes, or formal economic evaluation.

Many reports rely on service-level data and stakeholder accounts rather than consistent clinical or system metrics, potentially overrepresenting favourable experiences and failing to capture unintended outcomes.

Future directions

Future evaluations should prioritise multi-site, quasi-experimental designs using a small, consistent outcome set aligned with this review’s findings: ED conveyance/diversion, use of involuntary detention or coercive practices, repeat crisis contacts, and downstream service linkage. Incorporating health economic measures would strengthen assessment of system impact.

Qualitative research remains important for understanding provider and consumer experience, especially in regional settings and in relation to cultural safety and continuity of care.