Key features of a trauma-informed public health emergency approach: A rapid review

COVID-19 is a major threat to public safety, and emergency public health measures to protect lives (e.g., lockdown, social distancing) have caused widespread disruption. While these measures are necessary to prevent catastrophic trauma and grief, many people are experiencing heightened stress and fear. Public health measures, risks of COVID-19 and stress responses compound existing inequities in our community. First Nations communities are particularly at risk due to historical trauma, ongoing socio-economic deprivation, and lack of trust in government authorities as a result of colonization. The objective of this study was to review evidence for trauma-informed public health emergency responses to inform development of a culturally-responsive trauma-informed public health emergency framework for First Nations communities. We searched relevant databases from 1/1/2000 to 13/11/2020 inclusive, which identified 40 primary studies (and eight associated references) for inclusion in this review. Extracted data were subjected to framework and thematic synthesis. No studies reported evaluations of a trauma-informed public health emergency response. However, included studies highlighted key elements of a “trauma-informed lens,” which may help to consider implications, reduce risks and foster a sense of security, wellbeing, self- and collective-efficacy, hope and resilience for First Nations communities during COVID-19. We identified key elements for minimizing the impact of compounding trauma on First Nations communities, including: a commitment to equity and human rights, cultural responsiveness, good communication, and positive leadership. The six principles guiding trauma-informed culturally-responsive public health emergency frameworks included: (i) safety, (ii) empowerment, (iii) holistic support, (iv) connectedness and collaboration, (v) compassion and caring, and (vi) trust and transparency in multi-level responses, well-functioning social systems, and provision of basic services. These findings will be discussed with First Nations public health experts, together with data on the experiences of First Nations families and communities during COVID-19, to develop a trauma-integrated public health emergency response framework or “lens” to minimize compounding trauma for First Nations communities.


COVID-
is a major threat to public safety, and emergency public health measures to protect lives (e.g., lockdown, social distancing) have caused widespread disruption. While these measures are necessary to prevent catastrophic trauma and grief, many people are experiencing heightened stress and fear. Public health measures, risks of COVID-and stress responses compound existing inequities in our community. First Nations communities are particularly at risk due to historical trauma, ongoing socio-economic deprivation, and lack of trust in government authorities as a result of colonization. The objective of this study was to review evidence for trauma-informed public health emergency responses to inform development of a culturally-responsive trauma-informed public health emergency framework for First Nations communities. We searched relevant databases from / / to / / inclusive, which identified primary studies (and eight associated references) for inclusion in this review. Extracted data were subjected to framework and thematic synthesis. No studies reported evaluations of a trauma-informed public health emergency response. However, included studies highlighted key elements of a "traumainformed lens," which may help to consider implications, reduce risks and foster a sense of security, wellbeing, self-and collective-e cacy, hope and resilience for First Nations communities during COVID-. We identified key elements for minimizing the impact of compounding trauma on First Nations communities, including: a commitment to equity and human rights, cultural responsiveness, good communication, and positive leadership. The six principles guiding trauma-informed culturally-responsive public health emergency frameworks included: (i) safety, (ii) empowerment, (iii) holistic support, (iv) connectedness and collaboration, (v) compassion and caring, and (vi) trust and transparency in multi-level responses, well-functioning social Introduction Disasters can be natural (e.g., fires, floods, severe storms, infectious disease outbreaks and pandemics) or human-caused (e.g., mass violence and genocide), both of which result in widespread disruption to communities. Impacts can include loss of life, damage to property and economic loss (1). Disaster management is a core function of public health, and these responsibilities are outlined in international obligations such as the International Health Regulations (2005) and various national and jurisdictional regulations, to provide for the effective management of threats to public safety. Increased stress is a natural response to a disaster (2), therefore consideration of mental health consequences is integral to the public health response.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel virus first identified in late 2019, which causes an acute illness called coronavirus-19 . The spread of COVID-19 has evolved rapidly into one of the most significant public health disasters of the past century. Declared a pandemic on 11 March 2020, COVID-19 is estimated to have caused 3.72 million deaths by 7 June 2021. Global case numbers continue to peak at approximately 380,000 cases per day, as newly developed vaccines are administered in 2021. Previous pandemics were caused by influenza viruses, such as: the A(H1N1) pandemic in 2009-2020 (100,000-400,000 deaths); A(H3N2) in 1968 and A(H2N2) in 1957-1958 (1-4 million deaths each); and A(H1N1) in 1918 (20-50 million deaths) (3).
All populations have been affected by COVID-19, whether by serious illness, complicated grief (4), lockdowns (5), economic insecurity (6), disruption to normal life activities, "fear" of the virus, eroding trust in authorities (7), and stigmatization of people of Asian descent (8). Predictably, the COVID-19 pandemic is causing significant mental health impacts (9,10), particularly for those directly infected or classified as "high risk" and required to quarantine, healthcare and other essential workers, as well as the general population (11), in addition to indirect effects such as reductions in help seeking for mental health conditions (12).
As with previous disasters that overwhelm our health, social and economic systems (11)-risks and poor outcomes from COVID-19 do not affect people equally. The COVID-19 pandemic has highlighted inequities and exposed the longstanding drivers of health inequalities within our society, with the potential for these inequities to be further compounded (13,14). The Diderichsen model (15) provides a framework for understanding how social position and social determinants intersect. In the context of COVID-19, risk of transmission and social consequences of public health measures (e.g., lockdowns) are likely to intersect, and there is a need to identify when and where we can intervene to prevent the health divide widening (15). In addition, the mental health impacts of COVID-19 can reduce the effectiveness of public health emergency interventions and shape the spread of the disease (16). For example, psychological impacts can affect adherence with public health advice (including vaccinations) (17).
The World Health Organization (WHO) has highlighted that inequities experienced by Aboriginal and Torres Strait Islander (First Nations) communities in Australia, compared to other Australians, are the most significant inequities in the world (18). Despite national commitment by all Australian governments to "closing the gap" in life expectancy since 2007, annual reports to parliament have shown little progress (19). In July 2020, a new "National Partnership Agreement on Closing the Gap" (20), was signed-for the first time including First Nations representatives as parties. This agreement recognizes that fundamental structural changes to the way governments (including public health authorities) work with First Nations communities is critical to closing the gap. This is exemplified in the pandemic response in Australia. No community representatives had been included in developing the 2009 National Action Plan for Human Influenza Pandemics, and First Nations peoples were significantly more affected by the H1N1 influenza pandemic than other Australians (21). Evaluation research recommended that First Nations peoples be engaged and included in future pandemic preparedness and responses, and during the first wave of the pandemic in 2020 First Nations peoples had been significantly less affected by COVID-19, compared to other Australians (21). The success has been attributed to First Nations leadership in community responses (22), which has informed legislative action, guideline development, health service planning and testing, health promotion, and advocacy (21). However, the outbreak spread to regional New South Wales and Victoria in August 2021 and has had a direct and devastating impact on First Nations people and communities. An emerging area of science of particular relevance to public health and public health emergencies, such as pandemics, is the understanding of trauma. There have been many studies and formal recognition of "post-traumatic stress disorder" (PTSD) in trauma victims, war veterans and communities exposed to disasters for decades (23), and key symptom clusters of re-experiencing events (triggers), avoidance, and a sense of threat (24). Growing consensus has led to the recognition in 2018 of complex post-traumatic stress disorder (complex trauma) in the International Classification of Diseases 11th Revision (ICD-11) (25), caused by repeated inescapable traumatic experiences, often involving interpersonal violation (24). Key symptom clusters include emotional dysregulation, negative self-concept, and relational disturbances, in addition to the features of PTSD. Complex trauma is most commonly associated with childhood maltreatment, which affects up to 50% of children worldwide (26) and it is increasingly recognized as an international public health priority (27) and a major root cause of health inequities (28-30). These effects may outweigh the impact of socioeconomic conditions (29); with an English study estimating that child maltreatment can be attributed to the national prevalence of other adverse behaviors and events: 12% of binge drinking, 14% of poor diet, 23% of smoking, 52% of violence perpetration, and 38% of unintended teenage pregnancy prevalence (30). In addition to direct health effects, evidence suggests that public health interventions may be less effective for people who experience complex trauma (31, 32).
First Nations communities are also impacted by historical trauma (33), which in Australia includes state-sanctioned removal of First Nations children from their families, disruption of family networks and increased exposure to violence. While community cohesion, access to services and cultural continuity have been shown to have a protective effect for some trauma related outcomes among First Nations peoples (21), within the context of colonization, the socio-ecological risk factors experienced by many First Nations communities are likely to amplify rather than counteract the complex trauma effects originating from adverse childhood experiences (22,23). The WHO European Review of the Social Determinants of Health and the Health Divide provides a framework for understanding how the intergenerational effects of complex trauma compound health inequities (34). These include: historical violence, leading to increased exposure to violence in early life, increased socioecological and socio-economic hardship, increased risks, and decreased effectiveness of public health interventions (31, 32); and intergenerational trauma transmission (35)(36)(37).
Enhancing our understanding of the physiology and epidemiology of trauma is particularly relevant for public health, especially within the context of the COVID-19 pandemic. Complex trauma occurs in response to prolonged exposure to severe threats where escape is not possible (24), which activates "fear" or survival responses from the amygdala, commonly referred to as "fight, flight, and freeze." Fear is one of the central emotional responses during the pandemic (38). Evolutionary behavioral science theorists propose that experiences of fear of infectious disease are unique to other fears, with both psychological and behavioral adaptions for avoiding infection (39). Negative emotions resulting from this fear can impact others (i.e., fear is contagious), and can make threats feel closer. People experiencing PTSD or complex trauma can be particularly affected, as existing "sense of threat" symptoms can be more readily activated. As events leading to complex trauma threats often occurred in early life, many people experience these responses as confusing and distressing, and may not link them to the initial "threat." Rates of severe mental distress have increased during COVID-19, particularly in areas where there are restrictive public health regulations in place to control the spread of disease (e.g., Melbourne) (40-43).
Understandings of trauma has important implications for public health emergency responses, including the need to address fear and stigma, social isolation and reduced connectedness (central to First Nations wellbeing). Many First Nations communities have experienced deep trauma as a result of previous state-sanctioned actions, ostensibly "for protection" of First Nations peoples, which may be reminiscent of state-sanctioned COVID-19 public health actions (44). These understandings have implications for public health more broadly, as "fear appeals" are a commonly used tool in a range of public health strategies, including COVID-19, tobacco control, road safety and immunization. A meta-analysis suggests that this can be effective if people feel capable of dealing with the threat (high degree of self-efficacy), but can be counterproductive and lead to defensive behaviors (flight, flight, or freeze) if people feel powerless to act (45). This is consistent with the parallel processing model (46), which is likely to be operant in these situations.
While there has been progress on developing traumainformed responses in health and social services (36, 47), and trauma has been identified as a key priority for First Nations communities in Australia (48), there have been no reviews of trauma-informed public health emergency responses for First Nations communities.

Objectives
The aim of this rapid review is to identify and describe trauma-informed public health emergency approaches. Specifically, we address the following research questions: Frontiers in Public Health frontiersin.org . /fpubh. .

1.
What are the core conceptual features of trauma-informed public health emergency approaches? 2. What are the reported outcomes from application of traumainformed public health emergency approaches?
The purpose of this rapid review is to inform a future stakeholder discussion to develop a culturally responsive trauma-informed public health framework for First Nations communities in Australia.

Methods
We referred to the Cochrane Guidance for refining methods for this rapid review (49) and have followed the PRISMA-E checklist (50) in reporting this review.

Eligibility criteria Participants
General population only. We used a stepwise approach to study design inclusion, as per rapid review guidance (49), placing emphasis on higher quality study designs and relevance to the study question. We excluded strategies or approaches specifically designed for individuals (e.g., substance use programs, individual mental health support), healthcare workers, schools and other direct responders to an emergency, and people working in (war veterans) or impacted by war. These are covered in other reviews (11,(51)(52)(53)(54) and the core conceptual issues for trauma-informed and trauma-specific support for these responder populations are likely to be different than approaches to support the general population in a natural disaster. However, we did include some studies where we identified relevant key concepts for a trauma-informed public health emergency response.

Interventions
We included any trauma-informed population-level public health emergency approaches targeted to respond to natural disasters (e.g., flood, fire, earthquake, cyclones, and epidemics/pandemics). Approaches that targeted communities affected by mass violence (e.g., war, terrorism, genocide) were excluded. However, relevant studies that addressed how previous experiences of mass violence intersected with responses to natural disasters were included.

Comparator/Study design
We included any peer-reviewed article published from 2000 onwards and written in English. We used a stepwise approach based on study quality, including intervention studies, descriptive/observational studies, qualitative studies, reviews, and expert opinion/commentaries.

Outcomes
We aimed to identify core conceptual features of traumainformed public health emergency approaches. We also aimed to identify any reported outcomes from applying such an approach, including: • Public health outcomes.
• Experiences and views of the population.
• Theories that explain observed phenomena.

Searching Data sources
We searched for potentially relevant studies from databases from 1/1/2000 to 13/11/2020. The following electronic databases were searched: Medline (OVID), PsycINFO (OVID), CINAHL (EBSCO), EMBASE (OVID) and two Web of Science databases (Social Sciences Citation Index, Book Citation Index (Social Sciences and Humanities).

Search strategy
The search strategy was designed around two core constructs:

Selection of studies
References were exported to bibliographic reference management software (EndNote) and then Covidence for screening. Using a standardized title and abstract screening form, the whole screening team jointly screened the same 50 abstracts to calibrate and build consensus on screening criteria. Titles and abstracts of all studies were then screened independently by two reviewers, with conflict resolution by a third reviewer.
Full-texts of all potentially included studies were retrieved and a pilot exercise was conducted with three reviewers to calibrate and test the full-text review criteria. Remaining fulltexts were screened independently by two reviewers according to the inclusion criteria. Disagreements were resolved by a group discussion or if necessary, by a third reviewer.
It was evident in the preliminary screening that there were limited high quality study designs evaluating the impacts of trauma-informed public health emergency approaches. During full-text review, we used a stepwise approach, which erred Heris et al. .
/fpubh. . toward inclusivity and categorized the degree of relevance to the study question as: • Relevant/high relevance: Population-level approaches considering trauma-informed public health domains, including explicit emergency responses.
• Partial/moderate relevance: Not explicitly an emergency approach but describes aspects of relevant traumainformed public health domains in an emergency context.
• Low or unclear relevance: Not explicitly an emergency approach, may describe some relevant components in emergency or other contexts, but unclear if this adds any additional value.

Data extraction
We developed a data extraction tool using Microsoft Excel to systematically extract the following data (File 2 in Supplementary material):

Risk of bias appraisal
Given the variety of studies and stepwise approach to study inclusion, we drew on an adapted GRADE approach (55) (see File 3 in Supplementary material) to categorize the degree of confidence from high, moderate, low or very low in individual studies as follows: 1. Intervention studies, descriptive/observational studies, qualitative studies and reviews started with "high confidence"

Data synthesis
We used a "best fit" framework synthesis approach to data synthesis in this rapid review (56). This approach enables a relatively rapid, transparent, and pragmatic process, and incorporates inductive thematic analysis techniques only for data that that does not fit easily within the framework themes. This approach is particularly useful for "policy urgent" questions and findings can be shaped to be more directly applicable.
We reviewed existing trauma-informed public health emergency frameworks and used the principles from SAMHSA's Concept of Trauma and Guidance for a Trauma-Informed Approach (safety, trustworthiness and transparency, peer support, mutuality, empowerment, voice and choice, cultural, and gender considerations) (57), as well as a synthesis of trauma-informed frameworks used to develop a conceptual framework of core principles for co-designing perinatal strategies for Aboriginal and Torres Strait Islander parents experiencing complex trauma (safety, trustworthiness, empowerment, collaboration, culture, holistic, compassion) (35) to form the a priori framework. We also included an "Other" category for data that did not fit the framework, for subsequent thematic analysis. Data were synthesized in tabular and narrative form.
To avoid double-counting of studies, we grouped papers that came from the same overarching study or where the relevant content is an application or critique of an existing framework. We refer to these papers as "associated references." . /fpubh. .

Study selection
The search yielded 9,922 articles after duplicates were removed, and a further 9,779 were excluded during title/abstract screening. We reviewed 148 full-text articles, and 48 articles were included in this review [40 "studies"-where 8 related articles (associated references) are grouped under the relevant primary "study" (of which there were 4)]. Reasons for exclusion at full-text review stage included a primary focus on mental health impacts, the wrong study designs, setting, or outcomes of interest, or not relevant to public health emergencies or traumainformed approaches. See Figure 1 for a detailed flow chart.
Most of the included studies were led by authors based in and writing about the United States [US 16 (58, 59, 64- (65,81,88). Three studies were not related to an emergency response but were trauma-informed strategies more generally (58,64,66). Two other references were neither a trauma-informed approach specifically or an emergency response [one discussed the ethics of distressing social marketing campaigns (84), one a thesis, outlined a proposed community resilience model in addressing adverse childhood experiences (86)].
The complete table of characteristics of included studies and study confidence is presented below ( Table 1).

Main findings
No studies were found which explicitly evaluated any outcomes following application of a trauma-informed public health emergency response.
We present here a brief overview of psychological impacts from an emergency, and how existing mental health conditions relate to the response, followed by reported public health outcomes, experiences and views, economic impacts and relevant theories. In the following section, we present the core components of a trauma-informed public health emergency response and relevant literature found.

Psychological response to an emergency
Included studies highlighted the psychological impacts of traumatic events. While the specific focus of this review is to examine trauma-informed approaches rather than impacts, we briefly outline some key aspects related to the capacity to respond to an emergency: Most people will experience some fear in an emergency. In COVID-19 this includes being fearful about one's own illness and risk of dying from COVID-19, separation from loved ones and loss of livelihoods for self and others, and availability of healthcare and food (69,78). These fear responses can influence behavior and may increase risk of contracting the virus. For example, during the Ebola outbreak people broke quarantine to access holy water as a cure, or ingested salt water (76). There were also economic impacts as people avoided businesses in .
/fpubh. . busy places (76). Fears may also result in stigma, reducing the likelihood that people will seek testing and treatment for fear of being rejected by their communities (69,76). During the early stages of COVID-19, people of Chinese or Asian backgrounds experienced racism and stigma (70, 71). Grief and loss are also common experiences during and after a public health emergency. People will be affected by illness and death among their family, friends and community leaders which will have flow on effects for mental health services (72). In a pandemic such as COVID-19, grieving processes, funerals and traditional rituals are disrupted with families unable to be with each other in final moments (69). People may also go on to experience "complicated grief, " marked by greater distress over longer periods, following traumatic deaths such as from COVID-19 and low social support (68,79). During/post disasters, people can also experience grief over the loss of possessions, as well as for the changes in the community, their sense of safety and their sense of contribution and value. "Grief leadership" is required (74).
There is an increased risk of negative mental health impacts, including depression, anxiety, post-traumatic stress disorder (PTSD), dissociative responses, acute stress disorder, panic disorders, demoralization, perceived stress, negative affect, physical health problems, and/or somatic concerns, poor sleep, increased substance use, and physiological indicators of stress (68,74). The broader impacts of an emergency event (including unintended consequences of the emergency response), such as financial and food insecurity during and post the event, can contribute to poorer psychological outcomes (66, 74, 78). The evidence varies on the extent and severity of mental health      Melton               impacts post-disaster, however it is thought that most of the effects are felt in the first year after the event and the severity is related to the degree of the exposure (personal injury, loss of property) (68). It is expected that COVID-19 too will result in these mental health impacts, similar to SARS, particularly among those who were required to quarantine, those working in healthcare settings, or those who contracted/had friends or family who contracted the disease (69). In relation to acute mental health conditions, emergencies such as the COVID-19 pandemic can influence many risk and protective factors for suicide (including barriers to accessing healthcare and prioritization of other health conditions, social isolation and loneliness, financial insecurity, strained interpersonal relationships, increased access to and use of alcohol, and other substances) (79). While there is a recognized phenomenon that suicide risk may diminish in the early weeks/months after an emergency during the "honeymoon period" it can then increase again in the following months/years (74). Key strategies to prevent suicide include population level interventions to support employment, address inequality and increase access to mental health care; encourage responsible media reporting that drives people to support services; as well as interventions to prevent increased alcohol intake and restrict access to suicidal means (79).
In an emergency response, people with existing mental health conditions, psychiatric disorders and trauma histories may be less prepared than others, less able to adhere to directions (and therefore of greater exposure risk), and experience disruption in medication supply or treatment (74, 79, 83). Those taking psychotropic medications will be at particular risk during extreme weather events as these medications can impair heat regulation and fluid homeostasis (74). People with psychiatric disorders may also experience a greater prevalence of risk behaviors/factors that are identified as increasing susceptibility, such as smoking and COVID-19 (79). Previous experiences of trauma such as in post-conflict populations and related conditions of traumatic stress, PTSD and depression, have been shown to increase risk exposure behaviors and reduce the capacity to take preventive actions for Ebola and HIV (83). Although greater exposure to war events and anxiety were associated with more Ebola preventive behaviors (such as vigilant handwashing), perhaps indicating more risk averse people with greater survival skills (83).
The groups most at risk of, or factors associated with, ongoing psychological distress post-disaster include: women and those with children at home; ethnic minorities; socially disadvantaged people particularly older vulnerable adults; people with few psychosocial resources; people with limited experience coping with disasters and/or cope by assigning blame or avoidance; and people with a psychiatric history (68).
While all will experience some psychological response to an emergency, and some will experience acute, longer-term impacts, it is important to normalize the emotional response to the traumatic event, understanding that people are having a natural reaction to an extreme threat and most people will recover well (61, 74, 103). Some will even experience an increased sense of efficacy or "post-traumatic growth" (74). This is similarly expected at the broader community level. Morganstein and Ursano proposes six phases of psychosocial recovery for communities: Pre-Disaster, Impact, Heroic (action for survival immediately after event), Honeymoon (peak postevent emotional highs and community cohesion, coincides with increased availability of support and resources for recovery), Disillusionment (following withdrawal of support services), Reconstruction (74). However, slow moving disasters may delay the honeymoon phase, or in the case of a pandemic prevent the community from coming together, which is key to recovery (74).

Trauma-informed approaches
While each individual will experience public health emergencies such as the COVID-19 pandemic in a different way, for some people, this emergency overwhelms their coping strategies and is therefore experienced as a traumatic event (62). Given the widespread exposure to the impacts of COVID-19, this has led to calls for a systems-level "trauma-informed" public health response (62).
Although the Substance Abuse and Mental Health Services Administration (SAMHSA) does not require a specific definition or approach to trauma-informed systems (57), the SAMHSA trauma-informed principles (safety; trustworthiness and transparency; peer support; collaboration and mutuality; empowerment, voice, choice; and intersectionality/cultural issues) have been used to identify core components of a trauma-informed public health emergency response. While not explicitly a trauma-informed approach, the Five Hobfoll Principles for Mass Trauma Interventions include several related and relevant concepts, that are to: promote safety, foster calming, enhance self and community efficacy, maintain connectedness, and instill hope (61). In line with this, FEMA (the US Government Federal Emergency Management Agency) and SAMHSA deliver a post-disaster crisis counseling program where local health professionals deliver 1-2 brief sessions primarily focused on practical information and supportive listening (103).
Additionally, during a disaster response a population may reach a "tipping point" (74). These are small events that have large downstream effects, which may result in reduced adherence to directives and consequently have an impact on the health system (74). Clear, consistent communication, equitable distribution of resources, and community engagement are key to avoiding tipping points (74). Fear-driven behaviors and stigma during an epidemic/pandemic should be addressed in public education through the media (76).

Outcomes of trauma-informed public health emergency approaches
While no studies explicitly evaluated any outcomes following implementation of a trauma-informed public health emergency approach, public health impacts, experiences and views, economic impacts of public health emergencies, and relevant theories identified within included studies that discuss trauma-informed approaches or relevant concepts are outlined below.

Public health impacts of emergency responses
Findings from our rapid review demonstrate that the public health impacts of the COVID-19 pandemic are inequitable. For example, one study highlighted the disproportionate COVID-19 infection and fatality rate among Black, Native American, Latino, and socially disadvantaged people in the United States, and that the pandemic was exacerbating stress from racial and social inequities (71). Further, the application of the Progress Plus Equity Framework (PROGRESS+) in an evaluation of multiple COVID-19 policies, demonstrated that there were consistently inequitable adverse impacts across different policies, populations and equity domains. It was concluded that these policies are most likely to impact the vulnerable and this exacerbates existing inequities or creates new ones (60). Importantly, the evaluation noted that the impacts across different equity domains interact and can have a multiplicative effect on people's work and living situations, including food security (e.g., factors related to age, socioeconomic status (SES), and ethnicity can increase physical risk of exposure but may also contribute to be disproportionate impacts for certain interventions) (60). As such, it found that worsening inequities from the pandemic response will in turn, counterproductively intensify the pandemic. Whereas, policies to address inequities can also work as a pandemic mitigation strategy by addressing the same social factors that increase risk of transmission (such as insecure work) (60). An illustrative example under the domain of SES was the impact of New Zealand's border closures, which aimed to reduce the risk of COVID-19 reaching the Maori community. This action had the potential to adversely impact social and economic activities (including tourism), and therefore the mental health of Maori and Pasifika people; financial and social interventions are therefore required to ensure the policy does not further exacerbate inequalities (60).
Specific examples of post-emergency mental health interventions included a crisis counseling program post-Hurricane Katrina, which was found to have successfully reached ethnic minorities. Through local efforts, the program was well-received and perceived as culturally sensitive, although it was not necessarily adequate for addressing more complex mental health outcomes (103). It can be useful to increase public awareness and recognition of trauma and its impacts on individuals (63), and note that experiences of trauma may lead to "unhealthy coping"' or risk behaviors for some (69,73,74).
The research evidence underscores the importance of responding to trauma both at an individual and community level (i.e., for community-wide trauma, and for individual trauma in the broader community context) (57). A whole community may respond to trauma in a way that reflects a largescale version of typical individual trauma responses, becoming fearful, hypervigilant and re-traumatized by repeat/similar events (57). This shared community-level trauma may then be transmitted as historical or intergenerational trauma (57). Just as "meaning making" is a form of trauma processing for individuals (74), healing community trauma similarly requires that the community is supported to make sense of the event and tell their story (57). Reconciliation may be a further approach to healing in large-scale post-trauma care (63). One review highlighted that a truth and reconciliation RCT intervention among victims of war crimes in Sierra Leone found that reconciliation processes resulted in greater social capital, strengthened relationships and increased public contribution. However, reconciliation also increased poor mental health outcomes (i.e., depression, anxiety and PTSD) (63).

Experiences and views Experiences developing and implementing emergency plans
Some studies reported the views and experiences of those involved in developing the referenced frameworks and emergency response plans and their implementation. The SAMHSA trauma-informed principles were developed with expert and public input with 2,000 respondents and 20,000 comments/endorsements. This process was to ensure that the principles integrated knowledge from clinical practice and the voices of trauma survivors (57).
Collaborative approaches were well-received and improved outcomes. One study and its associated reference reported positive feedback and increased engagement and motivation among those participating in community disaster preparedness planning (91, 104). The "Guided Preparedness Planning" intervention was a collaboration between health districts, academic partners, and faith-based organizations. Feedback was positive, with participants reporting a better understanding of disaster mental health and plan content and enhanced confidence and efficacy to enact disaster plans (91). Evaluation of Psychological First Aid (PFA) training found increased confidence in providing PFA, expressing empathy, differentiating between distress and dysfunction, and making referrals/advocating (104). The Colorado Crisis Education and Response Network (CoCERN) partnership approach to supporting disaster affected communities received positive feedback from Red Cross representatives for the effectiveness and efficiency of a disaster response, particularly in relation to . /fpubh. . the inter-agency partnerships with community mental health and the Red Cross (85).

Individual experiences of COVID-and other outbreaks
A range of views and experiences of individuals were reported specific to the COVID-19 outbreak including experiences of fear, mistrust and confronting inequity. A study of COVID-19 related fears in the Czech Republic found that the four most common fears were: (1) negative impact on their own household finances, (2) or of others, (3) availability of health care, and (4) food security (78). Food insecurity was reported in many settings as an impact of lockdowns including in communities across Africa; quarantined refugees and insecure workers in Lebanon, and students in the US and elsewhere missing meals due to school closures (60,75). In Sierra Leone, Ebola survivors reported fear and depression when they suspected they had Ebola and community stigmatization after being released from treatment centers (76).
A qualitative study of Chinese college students who experienced distress during COVID-19 quarantine reported excessive internet/smartphone usage to manage their anxiety, insomnia, social disconnection and mistrust of official sources, but that this behavior exacerbated the effects (97). Another study looked at the impact of exposure to COVID-19 misinformation. It found that misinformation exposure was associated with misinformation belief, which was associated with reduced COVID-19 knowledge and preventive behaviors-but exposure itself was not directly negatively associated with knowledge or behaviors (90).
A study where African American pastors worked with public health experts to communicate with their community members found that people were dependent on family and the church in times of crisis and did not trust medical experts due to ongoing and historical harms (67). Community members were also confronted by reported statistics confirming the inequitable impacts of the pandemic: "We always knew that there were health disparities in the community, but hearing out loud that we are dying at a higher rate was devastating" (67).

Economic impacts
There were no studies reporting the economic impacts of a trauma-informed emergency response in practice. However, some studies described the social and health harms from the economic impact of the pandemic, noting that it can be a major source of distress and a barrier to seeking healthcare (97). One described the potential for increased risk to children in foster care as school closures may cause some to re-evaluate their capacity to care for a child and the importance of providing paid leave and economic assistance to carers (82). Similarly, former foster children living in college accommodation may experience homelessness as tertiary institutions close (82). School closures also impact a child's food security where they provide meals (60). Another study highlighted the economic downturn from the pandemic as a potential risk factor for suicide through unemployment, financial difficulties and worries about the future (79). While there may be a reduced specific focus on suicide prevention by governments due to economic impact of the pandemic, there may instead be a greater investment in health policies generally, short/long term welfare support, and a strengthened mental health system-all protective against suicide. The key to reducing suicide in an economic downturn is addressing unemployment, providing job search support and universal basic incomes (UBI) (79). The provision of a UBI was advocated for in another paper, noting that Spain had introduced one to buffer against the risks/effects of the pandemic (89).
Two studies touched on inequity in the context of economic impacts of COVID-19, noting that the already disenfranchised populations of the US are those most adversely impacted (71). The Progress Plus audit of COVID-19 policies found that a number of policies were related to addressing economic impacts: South Africa topping up child support grants for those living in shanty towns, experiencing economic hardship and unemployment through insecure work as street vendors; cash payments for workers in Kenya, Nigeria and Lebanon; food supplies and nutrition support for refugees in Lebanon and US families; and the previously highlighted concerns the New Zealand lockdown's impact on tourism will exacerbate the existing inequalities for Maori (60).
Several studies touched on the cost associated with public health emergency responses. Modeling demonstrates the need to resource disaster preparedness as the cost of psychological and behavioral interventions post-disaster can be equal to, or greater than, the reconstruction costs (74). Three discussed the need for cost-benefit analyses to demonstrate the greater efficiency of population level responses (over individual treatments) and the importance of addressing the upstream social determinants of trauma and mitigate suffering at the individual level (58,61,66). Although prevention approaches "pay for themselves" over time, adopting trauma-informed practice at the population level will require increased investment through new funds or reallocation of resources (for training, research, and data systems) (66).

Relevant theories
There were several specific models, theories, frameworks and broader concepts, ideas or approaches that were relevant to a trauma-informed emergency response. These Core concepts of a trauma-informed public health emergency approach Table 2 provides a summary of primary studies (and associated references) covering literature relevant to core components of a trauma-informed approach and contributing to the framework analysis, with a synthesis of data relevant to each concept reported in text below (note: we reference the primary study in-text in the first instance unless there is a specific point raised only in the associated reference not also covered in the primary study. Table 2 details the components identified in each of the primary studies and/or the associated references where appropriate). Three studies (59, 62, 72) [plus two associated references (98, 100)] described proposed features or concepts of a trauma-informed public health emergency response. A further four, while not explicit trauma-informed responses highlighted the need to take existing trauma into account when responding to public health emergencies (67, 75,76,83).

Safety
Twenty-four primary studies contained information relevant to the concept of "safety" (58-61, 64-66, 68-70, 73, 74, 76-80, 82, 83, 85, 86, 93-95). This included physical safety (such as evacuation or protection from a threat) (61,64,65,73,93) and reassurance of the safety of others and loved ones (61); providing financial and food security (93); and access to healthcare (76,79,93). Feeling a sense of safety, including through effective leadership and communications was important; but may be reduced by the reoccurrence of trauma memories and limited ability to assess realistic threats or exposure to misinformation/traumatic media that can lead to fear-based behaviors and non-compliance (61,68,73,74,76). This "felt safety" is critical to trauma-informed settings such as health systems, schools, and the justice system (57, 66, 101). People may also be experiencing fear of stigma from contracting an infection (76,79).
Social norms, social isolation, and social support are also important for safety and relate to sources of information, advice and support in the event of an evacuation as well as the behaviors related to attachment theory (94, 103). It is important for disaster responses to promote a "return to normal, " working quickly to re-establish routines and community assets (65,93).
Communications and information from governments and media can have a significant impact on people's safety/sense of safety. Leaders and governments can both increase and decrease a sense of safety, and may intentionally undermine safety for political reasons (61,74). Communications about the actions to take and available supports in response to a threat should follow established Risk Communications principles, as poor communication erodes trust and reduces compliance (74, 80, 95).
The media may also have a commercial incentive for repeated broadcast of traumatic images, which erodes safety and impedes recovery; responsible reporting and supportive broadcasting should be encouraged (61,74,82,103). While information seeking may be used as a coping mechanism to control anxiety, this information, including through the media, may increase anxiety, cause confusion and retraumatise people. Recommendations include reducing exposure and enhancing media literacy skills to identify propaganda/misinformation (61,74,83,103).
At the service level, practices that can compound trauma include coercion, isolation/segregation, and restraints (57). There is a risk this may increase to restrict movement during an infectious disease outbreak. These services may also employ people with their own histories of trauma who, without support, are retraumatised at work, or may experience secondary or vicarious trauma (64).
An associated concept within safety was Human Rights (69). When designing policy/emergency responses it is important to consider whose safety is being prioritized, such as in drug policy (58,99), or whether there are adverse, unintended or inequitable impacts for vulnerable sub-groups, such as increasing the risk of one threat to address another (e.g., domestic violence during stay-at-home orders) (60,69,74,77,79,82,103). In Argentina, 20 women were killed in the first month of COVID-19 stay-athome orders and police responses to reports of gender-based violence and missing women were considered negligent (77). Children may also be at increased risk of violence due to stressors of the pandemic and school closures (82).

Trustworthiness and transparency
Eighteen studies included information relevant to the concept of trustworthiness and transparency (58, 59, 61, 65, 67, 70, 72-75, 78-80, 82, 84, 90, 95, 97). Good communications were frequently cited as a way to be transparent and generate trust, such as providing regular, clear, and consistent information. Suppression of information can lead to mistrust, whereas good communication increases compliance with directions and promotes confidence, recovery, resilience, and mitigates panic; Bowen . . . (99)

Sun et al. (97)
x Indicator Key: Primary studies (bold); Associated references (italicized); + Study contains content related to concept; x No reference to concept; -Unclear.  Mistrust/distrust of authorities is a key concern and can have mental health impacts (65,67,74,95,97). Coupled with poor information/communication, it can also lead to noncompliance. Early and decisive action by governments builds trust and trust in the response is key to recovery and resilience, particularly when this belief is established pre-event through transparent planning (74, 75, 95). When there is a lack of transparency or poor communication, this can result in reduced awareness of protective behaviors or non-compliance because of distrust, and belief in conspiracy theories or misinformation. Consequently, communities may believe that the response is ineffective or perceive inequitable distribution of insufficient resources (65,73,74,90,95,97). Policies such as quarantine may also contribute to mistrust and non-compliance (73).
Working collaboratively with the media to ensure the transparent dissemination of accurate information and no fearbased reporting is important; as is increasing media literacy because people may seek out alternative sources of information (through social media) to fill the gap when they begin to distrust traditional media (70,74,78,79,82,90).
People will look to leaders and trusted groups in an emergency (including professional associations, faith-based organizations, and local groups) and these leaders should aim to be highly visible and avoid scapegoating others (61,67,74,80). Developing trusted relationships at the community level pre-event is also important, to maximize transparency and accountability in communications (including through developing a shared language and understanding) and minimize insider/outsider dynamics (80, 84, 95).
In other settings, trust and transparency should be embedded within policies [such as drug policy (99)

Connectedness and collaboration
Expert consensus is that emergency responses should promote connectedness and collaboration (61,68,74,103). This overarching grouping includes the two original standalone SAMHSA concepts of Peer Support and Collaboration.
Peer support is a facilitator of other key concepts and components of emergency responses including safety, hope, .
trust, collaboration and recovery (57). A related concept, social capital, is also important for community resilience (86, 103, 104). As such, public health emergency responses and policies must prioritize restoring social supports, systems, communications and rituals; and promote supportive relationships including creating opportunities for connection for isolated people (58,61,65,67,73,76,87,94,99,101,103). It may be possible to facilitate this through the use of media and technology, including supportive broadcasts, mobile phone use and social media, but for some may contribute to phone addiction (78,97). Facilitating social support is important as it can moderate trauma and reduce stress, promotes individual and community efficacy and resilience, can encourage adaptive or preventive behaviors through sharing of practical information and experiences (shared trauma, storytelling and coping) (61,63,65,75,78,81,86,92,95,101,103,104). For people and communities who have a strong connection and attachment to place, this in itself may be a form of support and can be part of recovery, including through eco-therapies (95, 103).
Lack of social support may have adverse impacts on mental health with isolation negatively impacting wellbeing, contributing to maladaptive behaviors, suicide risk, and domestic violence (61,73,76,79,81,82,92,94,97,101). Some of this is explained by "attachment theory" whereby insecure attachment triggers these maladaptive behaviors, violence, and xenophobia (94). Emergencies and responses may result in reduced peer support and see increased conflict through the reignition of historical social/ethnic tensions; inequitable distribution of resources/competition; and communications that inadvertently stigmatize a target population group (61,84,95). Further, stigma may result in a community not welcoming an infectious disease survivor back (76).
Social support is important for both how people respond to an emergency and recover afterward. Those with strong social support are twice as likely to evacuate in an emergency than those with weak supports (103), and those with low levels of community support have greater likelihood of PTSD and depression symptoms post-event, with community support having a "buffering effect" on mental health outcomes (81). However, this effect was only observed in non-urban areas (81). Social support within the family is critical during an emergency as a resource more likely to be utilized than professional support; it contributes to individual and community resilience and is particularly important for young people (61,65,71,86,103). Community bonding is most likely to occur during the Honeymoon Phase (74), but this may dissipate overtime and individuals may experience relationship burnout (61).
Local community organizations have an important role in providing social support to their community members, including through Community Health Workers, particularly for those communities with historical trauma; but there is also an opportunity to provide professional peer support through interagency relationships across organizations/levels of Government (58,65,88). Similarly, leaders have a role to play in providing social support whether they are formal or informal leaders, including "grief leadership" where they help their communities process and understand their losses (74, 88). Leaders need their own peer supports and to practice self-care to be able to continue to provide this support to their communities (74, 88).
Many studies discussed the importance of strong relationships for cross-sector/cross-system/multi-jurisdictional collaboration to address broad determinants; minimizing insider-outsider dynamics through early establishment of ongoing relationships; using shared resources/staff to build consistency and communities of practice; with these collaborations likely leading to improved community resilience and better health outcomes (61, 65-67, 71, 73, 74, 80, 86-88, 91, 95, 101, 103, 104).
Participation from the target population (including disaster victims, eco-dependent communities, and clients), in the planning and response, including in the design of communications and messages and of policies is important for addressing power imbalances, utilizes local knowledges; increases efficiency of resources; promotes community efficacy, resilience and capacity building; and provides mental health benefits including increasing empowerment reducing helplessness (57, 58,61,66,68,71,72,74,80,81,84,85,88,91,95,99,103,104). This included the importance of local leadership and control (61,65,85,103).
Interventions should maximize existing community strengths and resources by using local practitioners, healers, and ceremonies; adapting to the local context and traditions (particularly around rituals and burials); this may include using spiritual or religious leaders for mental health supports; as this adaptation will enhance credibility and increase service access (61,67,68,71,74,76,85,87,88,91,95,104). Supporting individuals to build self-efficacy and through advocacy is another form of collaboration and is a role played by Community Health Workers (58,61).
Another aspect of collaboration was to work with media companies to ensure accurate information is disseminated and misinformation on social media is countered (74).
Key to empowerment was the sub-concept of efficacy. This related to both self-efficacy (including self-esteem and belief in the ability to manage the response) and community or collective efficacy (including selfgovernance, self-sufficiency, and "Community Competence"); with the two coming together through "social capital" (with group belonging leading to better outcomes and empowered communities promoting individual resilience) (61,63,66,68,71,86,101,103,104). This relates to peer support in that having community support gives individuals confidence to take action (61).
Resilience was a further related sub-concept. Resilience was defined as the "other side of trauma" and may be a quality, personality, process, outcome; there can be individual, community, national and socio-ecological resilience; it acts as a social buffer against adversity and can be promoted through interventions including Psychological First Aid; at the community level this resilience includes economic development, social capital, information/communication, community competence; resources; partnerships and networks; and engagement with vulnerable groups (61,63,68,80,81,103,104).
Being able to enact choice, voice, power, agency, selfadvocacy and control (including as part of collaboration) promotes empowerment, resilience and wellbeing; this may include contributing to decision making, planning, message testing and community activities; helps to address the lack of diversity in decision making bodies and values local and Indigenous knowledges (58,61,63,66,72,77,80,81,84,85,88,95,103,104). To facilitate this individual and community contribution capacity building is necessary. This includes teaching problem solving skills to individuals, enhancing the survival and technical skills of a community to build a sense of mastery and control; and supporting communities to deliver services directly to their members (61,68,69,71,88,95,101). Empowerment is only achievable with adequate resourcing. Where there is inequity in distribution of resources this erodes efficacy in already vulnerable communities and is critical for community resilience and collective efficacy (61,103).
Another related sub-concept was hope or loss of hope/hopelessness. Traumatic events can result in feelings of loss of power/control, hopelessness, despair and futility when people have lost loved ones, employment, are experiencing uncertainty, and feel disconnected from decisions; people need hope to recover from trauma which may be facilitated through shared experiences, normalizing reactions, and enhancing agency through participating in community responses and working toward positive action-orientated future goals/outcomes (61,66,68,79,81,95).
Coping was linked to hope, as people struggle to cope when they lose hope. Thus, may result in negative or maladaptive coping strategies; whereas positive emotions promote coping and increase functional capacity, likely facilitated by social supports (61,68,73,74). The extent to which someone feels they can cope relates to whether they feel a sense of personal strength or that they are a victim and are feeling anger and resentment. However, through support and empowerment it is possible to help someone transition from "victim status" to "survivor status" (61,74).
Also related to empowerment is the psychological construct of "Sense of Coherence" (SOC) and its role as a buffer against stressors (96). One study found that higher levels of SOC before the COVID-19 pandemic resulted in smaller changes in psychological symptoms and may be a universally beneficial buffer against mental health stressors for groups experiencing both high and low levels of stress (96).
Four studies noted that how individuals respond to a public health emergency or traumatic event is influenced by their different cultural backgrounds, histories, and experiences and that those with previous trauma may be less able to adhere to public health directions (57, 58, 64, 67). Experiences of historical trauma was specifically mentioned by four studies (57, 58,75,80). These trauma histories along with socio-cultural factors mediate efficacy and the effectiveness of "self-help" strategies (61).
Many studies highlighted socio-cultural determinants and equity, noting that it is existing factors that determine who is most able to respond and most likely to be affected; the importance of addressing upstream drivers; how responses, such as in COVID-19, can exacerbate inequalities or create gendered impacts (including risk, labor, violence); but there are opportunities to maximize cultural strengths (such as through storytelling) (58,60,61,67). The lack of diversity on many decision making bodies was thought to contribute to the disproportionate impact of emergency responses in some population groups, such as women (77). Relevant to this concept was also human rights (68).
The socio-cultural determinant of experiences of racism and discrimination may increase during an emergency particularly where inequitable distribution of resources inflames historical racial tensions/in-group out-group divisions; where one population group is blamed or stigmatized (such as anti-Asian sentiment during COVID-19); and may be activated by insecure attachment (61,80,84,94,95). Interventions must be culturally sensitive and adapt to the local context, needs and practices respecting local cultures and autonomy; this includes provision of services in-languages, tailoring messaging, engage the population in the development of an intervention (and building these relationships early); and finding safe ways to accommodate Considering cultural sensitivity and adaptation will increase service utilization. This might include: increasing engagement through local partnerships; offering free support services for minority groups; recruiting local/Indigenous people to deliver safe services; build on cultural strengths to promote healing; and address historical mistrust, biases, and discrimination (57, 58,67,68,74,76,80,104). In some countries, the response to an emergency at the national level may include resistance to any investigation of the original cause of an event or disaster (88).

Holistic support
Twenty studies were categorized as having content related to the concept of "holistic" including the need for responses that address a range of needs (61, 65-69, 71, 72, 74-76, 79, 83, 86, 87, 89, 93-95, 99). Many studies noted the importance of combined, comprehensive, and multifaceted or multidisciplinary approaches (67- 69, 71, 72, 74-76, 86, 87, 95, 99). This included offering different interventions for changing needs over time that address all aspects from acute physical needs (safe shelter conducive to rest) to broader supports and resources that mitigate trauma, improve quality of life and social functioning (including healthy relationships); ensuring that public health integrates mental health and cultural/spiritual supports (as need to address distress and anxiety to be able to comply with public health directions); and using communitywide programs that address broader social determinants. Further needs included the provision of essential services or meeting essential needs (safe shelter, food security, healthcare, school and childcare; other physical needs); that providing these may mitigate maladaptive responses from anxious attachment; and that doing so must take into account privacy, dignity, and liberty (65,74,93,94). A related sub-concept was about preventing resource loss (psychosocial, personal, material, structural (including jobs/organizations) resources) and making financial support available including through Universal Basic Incomes (61,79,89,94).
Studies talked about the importance of compassion, dependability and empathy including through partnerships that practice "reflective listening and expressive empathy" as trusting relationships promotes wellbeing (64,104). Some referred to solidarity and humanitarianism (75,78) as well as providing social support programs for isolated and peer listening programs; noting that individual resilience relates to the buffering effect against adversity from community support (67, 86, 95).
Awareness and understanding of trauma was noted to be important including raising awareness and helping people to understand trauma behaviors and experiences to avoid retraumatisation; ensuring communications do not re-traumatize people (63,83). While equally the sub-concept of calming and normalizing stress reactions was also important (61).
Several studies emphasized the need for emergency responses to compassionately accommodate a range of needs which may include addressing mental health, panic disorders and substance use; provide supports specific to the elderly (dedicated shopping hours and home food delivery services, helplines, anti-stress broadcasts); and ensure privacy, dignity and liberty are maintained (72,78,93).
Compassion or lack of compassion around grief was also raised in three studies. This included that it was important for people to see a celebration of the deceased (such as televised eulogies so mourners know loved ones are missed); but notes that public indifference to deaths in the elderly can compound grief among families (67, 74, 79). The importance of leaders to practice "grief leadership" was also noted including recognizing the loss and trauma experienced, giving hope for recovery and the marking of the anniversary of the traumatic event as key to recovery (74).

Leadership (trauma-informed leaders)
Leadership was a cross-cutting concept that has been addressed in several previous sections including that leaders can both increase or decrease sense of safety (61,74); that informal leaders may emerge spontaneously from communities (74); leaders must practice self-care and be aware of their own distress reactions as this can impact the community's ability to cope (74); the importance of "grief leadership" and marking disasters anniversaries as memorializing is an important aspect of the community recovery process and not acknowledging the anniversary can be damaging and demoralizing (74); that good governance is the most important factor in public health .
/fpubh. . response (88); that different leadership strategies are required for different types of events (e.g., a localized disaster vs. a national pandemic response (72); and finally that leaders must support trauma-informed responses through ongoing commitment, attention and organizational/cultural change (64,98).

Communication and information
Similarly, issues around communications, information and the media have been raised under several of the preceding concepts.
Studies found the media can be traumatizing and increasing feelings of distress with a demonstrated dose-effect from repeated exposure to traumatic images through the media (61,78). Despite the negative and traumatizing impact the media may have, people may feel they need to keep listening to stay informed, but this in turn may reduce the behavioral capacity of someone to respond and may even increase suicide risk (61,71). Given the established relationship between existing mental health conditions and reduced capacity to take preventive action, it is critical that public health emergency communications take into account existing trauma and avoid re-traumatizing the population when communicating risk of death (83).
Communications have the power to shape beliefs and attitudes. On the one hand they can address fear and stigma; but on the other can also increase stigma when targeting one population group if framed as blameworthy (76,84). Several studies touched on exposure to accurate information as well as misinformation or lack of information. This included the way that poor government communications or lack of information may cause distress and lead to mistrust of government and medical institutions, increase access to misinformation, increase low adherence, non-compliance, or maladaptive responses and susceptibility to conspiracy theories (73,97).
While social media may have an important role to play in targeted, local information; the dissemination of misinformation is largely unregulated; and increased use of social media while social interactions are reduced (during a pandemic, for example) may further increase anxiety (74, 97). There is a need to ensure media companies follow existing regulations and codes (such as WHO reporting guidelines) and for governments to work with media companies and social media platforms on regulating misinformation and non-traumatizing broadcasts (78,79).
Ultimately, studies recommended following established risk or crisis communication principles, as this will most likely result in desired behaviors. This approach includes ensuring communications are interactive, clear, consistent, credible; take into account population sub-group communication needs; and are continued throughout extended emergencies (as perception of risk leads to adaptive behaviors) (69,73,74,95). Visualization of core concepts identified from the international evidence to inform development of the trauma-informed framework The originally identified core concepts from the SAMSHA 6 Guiding Principles to a Trauma-Informed Approach and the Healing the Past by Nurturing the Future Trauma-Integrated Care Conceptual Framework, have been combined with additional key factors identified in this review of the public health emergency literature, and are illustrated in Figure 3 above, including those from the 5 Hobfoll Principles for Mass Trauma Interventions. These concepts will be workshopped with community members, experts and key stakeholders in the COVID-19 pandemic response, particularly with First Nations people, and used to develop a proposed trauma-informed public health framework.

Discussion
Public health emergencies, by definition, represent a significant threat to people's lives. Protective "stress" responses are natural but can be distressing and have significant effects on physical, social and emotional wellbeing, as well as people's behavior, which can impact the effectiveness of the overall public health response. Hence, we argue, it is time for trauma-informed public health emergency responses which explicitly recognize and attempt to mitigate stress responses, and consider equity and the populations most at risk. In this review, we found no studies that described or reported outcomes from a trauma-informed public health emergency approach. Thus, we propose a framework for .
/fpubh. . discussion, based on literature from included studies related to core concepts of trauma-informed approaches. These interdependent concepts or principles include: (i) safety, (ii) trust and transparency, (iii) empowerment, (iv) holistic support, (v) connectedness and collaboration, and (vi) compassion and caring. Important supporting strategies include provision of basic needs and resources (such as food and safe shelter), ensuring well-functioning social systems, comprehensive multi-level responses, and human rights and justice. Key enablers of these principles are leadership, communication, cultural responsiveness, and a commitment to equity. Together, these components feed into the overarching goals to achieve: (1) a sense of security, (2) resilience, (3) wellbeing (4) self-and collective-efficacy and (5) hope.
The purpose of a trauma-informed public health emergency framework is not to describe essential public health emergency functions already outlined elsewhere, such as the key pillars under the WHO COVID-19 Strategic Preparedness and Response Plan: (1) coordination, planning, financing and monitoring; (2) risk communication, community engagement (RCCE) and infodemic management; (3) surveillance, epidemiological investigation, contact tracing and adjustment of public health and social measures; (4) points of entry, international travel and transport, and mass gatherings; (5) laboratories and diagnostics; (6) infection prevention and control, and protection of the health workforce; (7) case management, clinical operations, and therapeutics; 8) operational support and logistics, and supply chains; (9) maintaining essential health services and systems; 10) vaccination (105). Rather, such a framework offers a "traumainformed lens" through which to consider proposed actions, and ways to mitigate effects of trauma and stress and ensure emergency response measures embed factors that promote resilience and recovery.
The core components we identified for the framework development as outlined above were informed by the SAMHSA 6 Guiding Principles to a Trauma-Informed Approach, the Healing the Past by Nurturing the Future Trauma-Integrated Care Conceptual Framework, and the key factors identified in the literature, including the 5 Hobfoll Principles for Mass Trauma Interventions. Several of the supporting and enabling components are related to or explained by other relevant, existing frameworks. Demonstrating that just as this trauma-informed framework does not aim to explain public health emergency functions, nor does it seek to describe the mechanisms of good public health and health inequities.
In our review, equity, socioeconomic position, and the social determinants of health were frequently identified as key factors that increased risk of being affected by an emergency or exposed to a hazard, greater likelihood of poorer recovery and mostly likely to be adversely impacted by universal responses. Strategies that address these issues support the core concepts outlined above and are underpinned by the overarching enabler of a commitment to equity. The detail of how these issues intersect through structural determinants to influence health behaviors, enable choices and impact service utilization have been welldescribed in the WHO Commission on Social Determinants of Health Conceptual Framework (106), the Health Equity Measurement Framework (107), and Health Equity in Australia: A policy framework based on action on the social determinants of obesity, alcohol and tobacco (108).
Similarly, for First Nations people specifically, addressing broader social determinants as well as a focus on human rights, community control and culture/cultural determinants of health is critical, as outlined in the Achieving Aboriginal and Torres Strait Islander health equality within a generation-A human rights based approach report (109) and the National Aboriginal and Torres Strait Islander Health Plan (110). Taken together, these reflect the importance of another of our overarching enablers, Cultural Responsiveness; a fundamental aspect of a framework for First Nations people. This embeds a holistic view of health. Research with Stolen Generations survivors found that while early pandemic response measures were effective in protecting against the threat of COVID-19, these measures negatively impacted physical, mental health and wellbeing through disconnection from family, community, culture, and country (111). As such, these key determinants of Indigenous health must be central to any public health response.

Strengths and limitations of the rapid review
We undertook a rigorous and inclusive search with strict screening protocols. However, the search was not exhaustive and may have missed some relevant studies. Further, the quality of the included studies ranged from evidence reviews to commentaries. Many relevant articles (letters and commentaries) about COVID-19 were identified in the search and were not peer-reviewed, with no evaluations of trauma-informed public health emergency responses. Thus, we have not been able to determine the strength of evidence for such an approach. However, a key strength of this review is the systematic application of existing traumainformed frameworks, namely the SAMHSA principles and that developed by First Nations people for the Healing the Past by Nurturing the Future project, to a comprehensive and extensive range of emergency literature and identify how already established core aspects of an emergency response align with trauma-informed concepts. This synthesis will provide the basis for further discussion and workshopping with First Nations communities and public health experts to develop a framework informed by the evidence that reflects an Indigenous worldview.

Implications for practice (services, communities)
Local leadership and control help to build trust in the broader response. Empowering and enabling community involvement is critical to the success of the response and can aid recovery. This engagement builds individual and community self-efficacy and reduces feelings of helplessness. Promoting caring and compassion is important for people to feel supported to take action and this aids in recovery. Fostering connectedness is also vital for wellbeing outcomes, and for receiving critical emergency information and support, and observing behavioral norms. While many people will experience increased connectedness in an emergency, it is important to recognize that this can diminish after the "honeymoon period." Services should work to facilitate connections for those who are isolated and where possible address threats to social cohesion, including behavior which may pose a threat to the safety of others and stigmatizing certain groups.

Implications for policy
Protecting public safety is the core responsibility of the public health emergency response, but some "safety" measures can be perceived/felt as "unsafe" by some, such as when coercive force is used to restrict movement. It is important for policy to consider adverse impacts and how these can reduce compliance and the effectiveness of the response. While reduced movement increases safety, it can negatively impact mental health and wellbeing. For some, staying safe and staying at home is not an available option. There must be a commitment to addressing equity in any policy response as there is potential to further increase inequities (and may have a multiplicative effect), whereas actively reducing inequity, such as through providing financial support and safe housing to allow people to comply with stay-at-home orders, will increase the effectiveness of the response. Good leadership and effective communication are vital for fostering trust in the response and the likelihood of compliance with policy measures. Transparently communicating key information is fundamental and this includes actively combatting misinformation, which may require dedicated regulation.

Implications and recommendations for future research
There is an urgent need for documentation and mixedmethods evaluation of trauma-informed approaches and outcomes. While there were several authors calling for a trauma-informed response to COVID-19 and other outbreaks, some relevant emergency response frameworks/strategies that contained related concepts, as well as indications the CDC have applied the SAMHSA principles to their public health responses, we found no evidence of the effectiveness of such a response. This is of particular importance for those communities at risk of heightened stress responses during a public health emergency, including those with existing trauma histories associated with government interventions, and those at risk of increased susceptibility due to structural inequalities (such as housing and insecure or frontline employment).
This rapid review sought to synthesize the public health emergency evidence through the prism of applying the principles of trauma-informed practice at a population level. The findings from this review will now be workshopped with experts and First Nations community members to inform the development of a trauma-informed public health emergency response framework for First Nations communities. We envisage that the resultant framework will be used to guide the current COVID-19 pandemic response and recovery, and in planning for future emergencies.

Conclusions
The effects of COVID-19 are highly inequitable for many in the community, including for Aboriginal and Torres Strait Islander communities impacted by historical and intergenerational trauma, racism and ongoing socio-economic deprivation associated with colonization. These experiences can affect a community's response and capacity to adhere to public health directions and demonstrates the need for culturally responsive trauma-informed approaches. Seeking to address inequities as part of the response will likely lead to greater effectiveness of the response overall.

Data availability statement
The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.

Author contributions
CH, MK, SG, CA, JM, CW, SB, and CC drafted the protocol. CH, MK, SG, CW, SB, and CC conducted screening. CH extracted and synthesized data. CC and CH drafted article. All authors provided input and approved the final draft.

Funding
The Paul Ramsay Foundation's mission is to break cycles of disadvantage in Australia. PRF focuses on the most stubborn barriers to change, where multiple cycles of disadvantage collide and experiences of disadvantage persist across generations.