Abstract

Background

For more than a decade, there has been substantial attention to and investment in emergency preparedness and response capacity for emergencies with health impacts. The importance of robust emergency preparedness and response systems for health emergencies is highlighted by recent incidents such as the Ebola outbreak in West Africa, the emergence of Middle East Respiratory Syndrome Coronavirus, natural disasters such as floods, and industrial-technical incidents like train derailments [1-4]. Preparedness for the diversity of events that may impact health is described as an ‘all-hazards’ approach, highlighting the importance of ensuring the system is prepared for a variety of potential threats. While there are multiple sectors with responsibilities for emergency preparedness and response, actions taken to prepare and respond to the population health consequences of emergencies fall to public health emergency preparedness (PHEP). PHEP has been defined as “the capability of the public health and health care systems, communities, and individuals, to prevent, protect against, quickly respond to, and recover from health emergencies, particularly those whose scale, timing, or unpredictability threatens to overwhelm routine capabilities” [5]. Examples of actions of PHEP related to health emergencies include surveillance and epidemiologic activities to monitor, detect, and investigate potential health threats, and the development and communication of information to the public [5]. In the context of the Severe Acute Respiratory Syndrome (SARS) outbreak of 2003, gaps were noted in the Canadian public health system including coordinated surveillance systems for detecting outbreaks and communication to the public [6].

Despite the investments into operational capacity for PHEP, a persistent challenge is a paucity of evidence to inform and guide practice [7-11]. Evidence-based approaches to public health practice have been recognized as crucial [12], alongside established practice in related fields of evidence-based medicine and health decision-making [13-16]. Evidence-based or informed practice in public health encompasses incorporating scientific evidence in selecting and implementing programs, developing policies, and evaluating progress [12]. In the PHEP field, however, anecdotal responses to recent events are typically used as the best available science [10]. A review of the emergency planning literature focused on the United Kingdom (UK) noted that the published literature for emergency planning is dominated by event reports [11]. This can be problematic in that outcomes and conclusions may not be generalizable to other populations, settings, exposures or interventions [12-14]. Public health in general aims to be informed by the best available evidence and there is an appetite to have more rigorous forms of evidence to inform PHEP practice [12,16,17].

While the PHEP knowledge base is dominated by event reports and narrative reviews [11], PHEP research of a more analytical nature has been undertaken in some recent emergencies [10]. This review focuses on primary and analytical research in PHEP in order to better inform research priorities for the field. Our objectives in undertaking this scoping review are therefore twofold: first, to develop a thematic map of the PHEP evidence base, focused on primary and analytical research; and second, to use this map to inform and guide an understanding of knowledge gaps relevant to research and practice in PHEP.

Methods

Results

Study selection and characteristics of the studies

The total number of citations retrieved through the search of indexed databases after duplicates removed was 3015. A flowchart of the article selection process is displayed in Figure 1. Three hundred articles met our criteria after title and abstract screening including additional sources from reference lists and grey literature. Reasons for exclusion of citations were predominantly related to emergency preparedness or management activities that did not meet the criteria of public health actions, based on the established definition. For example, hospital-based preparedness; mass casualty preparedness, triage or health care; and preparedness for institutions such as long-term care.

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Figure 1

Flow diagram of pre-consultation article selection process.

Data charting by descriptive numerical summary was undertaken for the 300 articles that were selected after abstract screening. The types of disaster were: all hazards or disaster type unspecified (39%); infectious natural hazards (31%); and non-infectious natural hazards or natural disasters (24%) (Figure 2).

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Figure 2

Types of hazards for studies identified in scoping review. 1. All hazards: dark blue, 2. Human-caused (terrorism): red, 3. Natural hazard infectious: green, 4. Natural hazard non-infectious: purple, 5. Technological: light blue.

The largest proportion of articles related to the response phase of the emergency management cycle (42%) and the second largest to the preparedness phase (34%). The prevention/mitigation phase accounted for 21%, while recovery was represented by only 3% of articles. The majority of studies were published by United States (US)-based authors (197, 66.3%), with Canada ranking second (23, 7.7%). The largest number of emergency events described in the published literature was from the US (126, 42%), with the second largest from Canada (18, 6.0%).

The majority of studies, 186 (62%), were non-primary research or descriptive articles. Thirty-seven (12%) were analytic epidemiology studies and 45 (15%) were descriptive primary research studies, such as surveys (Figure 3). Of the group of non-primary research or descriptive articles, 50% were emergency event-related descriptions such as “lessons learned”, event reports or case studies; 37% were literature reviews that did not employ systematic review methodology; 6% were commentaries; 3% were systematic reviews and another 3% were practice guidelines. A final 1% consisted of media or magazine reports that were captured in the search.

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Figure 3

Types of study designs in scoping review. 1. Descriptive studies: dark blue, 2. Analytic epidemiology studies: red, 3. Descriptive primary research studies: green, 4. Grey literature: purple.

Eighty-two primary research and analytic epidemiology studies were selected for further review; these were reduced to 58 articles after exclusion of computer simulation studies. The final group of 58 articles related specifically to the research question. No grey literature met the criteria of being evidence-based or evaluative in nature. Within the final group, the most common study design was survey methodology (60%) including cross-sectional population surveys, surveys using qualitative methods such as key informant interviews, and surveys conducted after training exercises as an evaluation tool. The cohort studies were largely retrospective administrative database analyses. Studies with an evaluation purpose were largely evaluations of a process change or of training.

Discussion

Previous reviews of PHEP evidence base documented the largely descriptive and anecdotal nature of the literature and found it challenging to draw conclusions as a result [7,11]. Rigorous and analytical research needs to be conducted to strengthen the PHEP evidence base to respond to practice and policy-related questions for the field [9,10]. This review focused on the body of primary research that has been conducted in the PHEP field and aimed to map important themes, for the purpose of furthering understandings of existing PHEP science and revealing potential knowledge gaps for future research. This scoping review is novel for the PHEP field in that it utilized published scoping review methodology with the identification of themes as they emerged, without applying a pre-existing framework [19]. In addition, the study included expert stakeholder consultation to validate and confirm the themes identified by the review, a knowledge translation step that is sometimes omitted in scoping reviews but considered essential [19].

The iterative identification of themes using the literature and survey methods resulted in the recognition of important cross-cutting themes for PHEP. To our knowledge, this is the first time that the cross-cutting nature of some PHEP themes has been documented. Based on these results, consideration of the themes of at-risk populations, gender and equity should be recognized as integral to planning and implementing PHEP research [83]. Although these themes may be viewed as similar they each have unique characteristics: at-risk populations vary depending on the hazard and risk, gender differences cut across virtually all population health issues, and equity speaks more broadly about disparities that may pre-exist within a given community. Resilience was the fourth cross-cutting theme [84]. Resilience is described as the intrinsic capacity of individuals, populations and infrastructure to resist and rebound from shocks and to then rebuild to a stronger state [84]. In national-level emergency management policy, resilience is established as the overall objective of all-hazards preparedness and capacity-building activities in order to reduce the impact of emergencies on a given population [22,85]; hence its inclusion in this category.

In addition to cross-cutting themes, the stand-alone themes with the largest number of papers included in the review were Surveillance, Epidemiology and Public Health Information, Communication and Education, Training and Exercises. Surveillance, Epidemiology and Public Health Information was the theme with the largest number of studies. This is not surprising given the integral nature of surveillance and epidemiology to public health, as well as the manner in which quantitative data are used for analytic processes to assess risk or measure outcomes of public health emergency events. Efforts in the US to identify key domains for PHEP are consistent and have similarly identified ‘health surveillance’ [86]. Communication is an area that has been noted to be problematic in post-emergency event assessments; thus, it is positive that research is emerging under this theme [6,87]. The social behavioural facets of communication relating to PHEP have recently been explored in the literature. For example, concepts of trust and preferences for certain characteristics of messaging highlight the contextual aspects that are emerging from PHEP communication research [40,43,45]. Important knowledge gaps were identified for communication in PHEP relevant to the use of emerging technologies. Education, Training and Exercises was another theme in which preliminary study on approaches to training for ‘hard skills’ such as technical skills and ‘soft skills’ such as leadership has been undertaken [53,54]. Nonetheless, attention to training as it relates to emergency decision-making in public health was highlighted as a gap in this review.

The complexity of PHEP is reflected in the knowledge gaps that emerged. For example, Collaboration and System Integration sub-themes pertain to multiple health-care stakeholders. Multi-sectoral partnerships and engagement has also been noted as important domains for PHEP operations in the US [86]. Opportunities for generating knowledge to examine complexities such as system integration could address knowledge gaps and inform operational activities and policy. Another notable knowledge gap relates to the theme of Quality Improvement and Performance Standards. Multiple publications have noted the importance of quality improvement and development of standards or metrics for PHEP [5,9,88]. Despite this, little research was identified that has empirically examined the development of standards and metrics. Research in PHEP that advances empirical knowledge in this area would be valuable.

This review has several limitations. First, this study specifically focused on research that was relevant to the actions and activities of public health as defined for the Canadian setting. The findings therefore may not translate to other countries that have differing scope of public health responsibilities. As was noted in the emergent themes, the importance of integration and collaboration within the health system is key for PHEP, and it is possible that this review did not capture the extent of public health connectedness to the rest of the health system, as found in the literature. This focus on public health was carefully defined, however, with the purpose of identifying themes and relevant knowledge gaps that specifically pertain to public health agencies and departments. Second, as with all systematic reviews, there is a possibility that literature was missed, which may have resulted in a lack of recognition of key themes or gaps. We used a rigorous search strategy for the indexed and grey literature to minimize this. In addition, we conducted stakeholder consultation in order that experts in the field would provide information and contribute knowledge that was missing. As a result of this iterative approach, additional articles were included in the final thematic analysis. Third, computer simulation studies were excluded due to scope of the current study, with a focus on the field-derived primary research studies. An attempt to account for themes that resulted from data-charting of this group was done and compared with the final emergent themes. In general, these studies pertained to vaccination and outbreak management, which were captured under themes of Communicable Disease Control or Surveillance, Epidemiology and Public Health Information. Finally, quality of research studies was not assessed beyond research design in this review and for this reason, the themes identified in the literature and the knowledge gaps do not take into account specific methodological strengths and weaknesses of the included studies. While quality assessment is ideal to include, we addressed the varying quality in the PHEP literature by focusing on identifying a group of articles that did not include event reports or ‘lessons learned’ commentaries, and focused on primary research studies.

A question that has been posed in a review of the emergency planning literature focused on the UK is whether “the traditional hierarchy of evidence applied to clinical research is appropriate in this field” [11]. The challenge of using the traditional evidence hierarchy to inform evidence-based decision-making in health has been raised outside the PHEP field [21]. The hierarchical approach to evidence is quantitatively oriented and does not elaborate on how context may modify the relevance of evidence [21]. Upshur et al. suggest that an inclusive definition of evidence includes both quantitative research that involves measurement as well as qualitative research that examines context and meaning [21]. This review included the breadth of evidence described in this taxonomy, and identified qualitative research in PHEP that attempts to capture meaning. The themes identified in this review for PHEP would support that both quantitative and qualitative methodological approaches will be valuable in generating knowledge to understand the complexities of gaps such as communication, collaboration and integration, and attitudes and beliefs. However, as noted by Upshur et al., such research will benefit from having a sufficient theoretical base that will allow it to have solid ‘scientific’ standing in the eyes of proponents of evidence-based practice. This is important given the high proportion of anecdotal event reports which share experiential and contextual knowledge but generally lack a sufficient theoretical base. In addition, there are recent studies highlighting that participatory and community-based approaches to research may have an important role in addressing some of the cross-cutting and stand-alone themes noted in this review [89,90]. Participatory methods hold promise for promoting inclusiveness across a community and examining the meaning that may underlie the complexities of the emergency [89]. These methods also model a collaborative approach that may promote resilience, enabling both research and community-building, thereby fostering the translation of knowledge to action [89,91].

Conclusions

Global health threats, which include emerging infectious diseases, technological events, and natural disasters, appear to be increasing in frequency and impact. This scoping review identifies the key cross-cutting and stand-alone themes that characterize the current state of the evidence base of primary research in PHEP. The identification of themes and related knowledge gaps represents a leaping-off point from which to identify research priorities and inform the further generation of practice-oriented research to advance PHEP. Based on the diversity of themes and knowledge gaps identified, collaboration in inter-disciplinary teams such as was utilized in the consultation step of this review and an inclusive definition of evidence, will be valuable in developing research that is both rigorous and relevant to the field.

Acknowledgements

Abbreviations

Footnotes

Contributor Information

Yasmin Khan, Email: [email protected].

Ghazal Fazli, Email: [email protected].

Bonnie Henry, Email: [email protected].

Eileen de Villa, Email: [email protected].

Charoula Tsamis, Email: [email protected].

Moira Grant, Email: [email protected].

Brian Schwartz, Email: [email protected].

References