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Factors affecting the preparedness of Helicopter Emergency Medical Services (HEMS) in disasters: a systematic review



One of the most significant advantages of Helicopter Emergency Medical Service (HEMS) in disaster relief efforts is their ability to reach inaccessible or remote areas quickly. This is especially important in the aftermath of natural disasters such as earthquakes, floods, or hurricanes, where roads may be blocked or damaged, and conventional ground transportation may not be available. There are many factors can affect the performance of Helicopter Emergency Medical Service (HEMS) in disasters. This study aims to investigate the factors affecting the Helicopter Emergency Medical Service (HEMS) in disasters.


The systematic search in Cochran Library, PubMed, Scopus, Science Direct, Web of Science, ProQuest, and Google Scholar databases between the first of January in 1975 and the thirty-first of May in 2023. The articles were selected based on the keywords of the authors. At last, the criteria were extracted from the selected ones.


The primary search included 839 articles. After studying their title, abstract, and full context, only nine articles, including two qualitative and seven quantitative ones, were chosen for analysis. After analysis and extracting data from the final studies, the preparation factors were categorized into 6 general classes of human resources: training and practicing, management, instructions and standards, equipment, and structure. Among these, the role of training is highlighted by holding practice and maneuvers to improve and prepare the personnel and manage disasters and incidents.


The results obtained from this systematic review provide a total view of the factors affecting the preparation of the air ambulance during disasters and incidents. It is recommended that senior managers and policy makers use the findings of the present study to identify the factors which affect preparedness of HEMS in disasters and take the necessary measures to eliminate to obstacles.

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As a part of the Emergency Medical Service (EMS), the Helicopter Emergency Medical Service (HEMS) is one of the fastest and most efficient ways to transfer injured and sick people during emergencies, natural disasters, and road traffic incidents [1, 2]. HEMS can play a critical role in providing access to injured and sick people, transferring them from an incident scene, and ensuring their survival [3]. Today, HEMS have been developed as a part of an advanced emergency service, so many countries use these services to transfer injured and sick people during ordinary and urgent situations [1], Moreover, HEMS can transport patients quickly, saving crucial time in emergency situations. In a disaster scenario, every minute counts, and HEMS can provide rapid transport to patients who need immediate medical attention. This is particularly important for patients who require specialized care, such as trauma patients or those with severe burns, who may not be able to survive the long journey by ground transportation. [2]. In particular, HEMS presents a higher level of clinical care than road ambulance systems because they require an experienced and skilled team to cover a large geographical area. HEMS are also expensive resources that are employed to maximize clinical efficiency and operational productivity in faraway places [4]. The preparedness of the health professionals and support staff is important to dominate against disasters and protect themselves and the community from them [5]. Preparedness during emergency calls includes three main stages: emergency planning (planning/prevention); emergency reaction, saving, and recovery [6]. Preparedness is the most effective approach to managing disaster risks and is essential for emergency medical service providers such as paramedics, emergency medical technicians, and other personnel [7]. The first step to designing and developing valid tools for the evaluation of EMS providers’ preparedness against disasters as well as adopting the proper strategies for their improvement is to identify the key dimensions of this preparedness versus disasters [7]. To ensure a safe, coordinated, and efficient response, HEMS teams require the proper, proportional, and enhanced programs, which should be combined in the main planning for incidents, emergency service, and regional health care. Quick delivery of HEMS personnel with advanced skills in incident management essentials and clinical leadership is of significance to providing an efficient medical response [8]. When the incident site is farther away or the usual access to paths is dangerous, helicopters are the only way to transfer personnel and equipment to the incident scene [9]. HEMS several presumable advantages compared to ground emergency medical service (GEMS) in general. First of all, HEMS facilitate rapid preclinical patients’ transport due to increased transportation velocity [10]. Additionally, HEMS can reach the operating site irrespective of traffic and road conditions [11]. Furthermore, HEMS medical crew members are supposed to be more experienced in trauma management improving preclinical treatment of traumatized patients [10,11,12].

Helicopters are commonly expected to reduce the arrival time at the operating site and the transportation time from the scene to hospital due to increased velocity and the capability to avoid difficult terrain or traffic hindrance [10, 11].

HEMS units require a proper, proportional, and enhanced project for important issues including medical, air, and technical aspects. HEMS should be combined with disaster management programs and other local (non)medical emergency services, including firefighting, police, and military, to allow a cooperative and coherent response and create a strong and efficient relationship in HEMS due to mobilization and coordination of teams if a large-scale incident happens [13]. Thus, this study aims to investigate the factors affecting HEMS preparedness during disasters.


Eligibility criteria and search strategies

Search strategy: Searching for this systematic review is performed based on the PRISMA (Preferred Reporting Item for Systematic Reviews and Meta-analyses) guidelines [14]. To extract the related studies, a systematic search was done from the 1st of January, 1975, to the 31st of May, 2023, on the English and coordinated peer-reviewed texts associated with the research question “Which factors affect HEMS preparedness during disasters?” To verify that no systematic review had been conducted in this field, a comprehensive search was carried out using the same systematic reviews. No identical article was found in the database. Searching was done in electronic databases such as Cochran Library, PubMed, Scopus, Science Direct, Web of Science, ProQuest, and Google Scholar. Also, other sites such as the Federal Emergency Management Agency, Pan American Health Organization, World Health Organization, and Google Database were searched to find reports and guides related to the subject. Surfing the internet, reading books, theses, and conference papers were all done using gray literature. Searching between the synonymous words was performed by the “OR” operator. Then, among the word groups considered a separate concept, the “AND” operator was used. Searching for the “title, abstract, and keyword” of articles was done on different databases. On databases such as PubMed, the subject title in Mesh was used to find articles. The search strategies used in this research are shown in Table 1. In this study, a comparison group was not included in PICO. Articles and reports based on the search keywords were selected by two authors, and finally, criteria were extracted from the selected articles. In the next step, a total list was prepared from all references to papers, and their titles were explored by the researchers. Papers not related to the target were removed. All steps for searching were repeated for more reliability. The resource management was performed by EndNote software version 20.

Table 1 The search strategy used is based on the factors affecting HEMS preparedness in disasters

Inclusion criteria

The title and abstract of articles were selected based on this; the components of HEMS preparedness during disasters should be included in the title, keywords, or abstract, and, eventually, the entire context of the article was analyzed according to the marketing tools. Among the papers, searching for this systematic review was recovered between the first of January, 1975, and the thirty-first of May, 2023. However, the articles that had not been published (grey literature), conference papers and guidelines, protocols, instructions, and reports of valid organizations were also examined. Published in the English language or has a complete English language version available. Both quantitative and qualitative articles were selected. The search keywords existed in the title, abstract, and keyword. The articles should be associated with the research question. Also, scientific articles should be published in journals evaluated by peer review.

Exclusion criteria

The articles referred to non-associated variables in the research question of this study was excluded.


Two authors reviewed paper titles in databases related to study question and inclusion criteria. Selected abstracts were then read. Two authors evaluated the paper after selecting studies that met inclusion criteria. The selected papers focused on inclusion and HEMS preparedness during incidents and disasters. The evaluation of these articles was performed by the PRISMA guidelines. Meanwhile, bias was also considered in the publication, and citations and articles with high citations were accurately investigated as well.

Data extraction

The information required was extracted from the papers based on the collected and summarized form. This form includes the corresponding author, aim and objective, population, sample, duration, design, data collection tool, methodology, results, conclusion, and the factors affecting preparedness. The summarized forms were completed for each selected paper. After completion, items of all forms were synthesized and illustrated in the descriptive tables. The authors performed this step, while others later contributed their ideas on the controversial issues. These forms were adjusted in the Word software version 2016. After studying the full text of these 9 articles, they were summarized in Table 2. The information includes title, corresponding author, study population, study sample, country, duration of the study, study design, data collection tool, methodology, results, limitations, conclusions, and factors affecting HEMS preparedness. Table 2. A summary form of selected final articles. By reviewing the literature, as well as the opinions of the research team and experts, similar factors and related to a theme were classified in one category. The results of categories and subcategories extracted from the systematic review have been shown in Table 3.

Table 2 A summary form of selected final articles
Table 3 Categories and subcategories extracted from the systematic review on HEMS preparedness in disasters


After searching the database, 839 papers were extracted. 90 repeated papers in different databases were removed. After investigating 749 papers, 310 were excluded because they were not in line with its aim. The abstract of 439 remaining articles from the previous step was studied and 303 were excluded due to being not associated with our aim. So, 136 full-text articles were chosen for our research, 26 were accepted, and eventually, only 9 papers were consistent with the aim of our study. Figure 1: PRISMA 2020 flow diagram for new systematic reviews which included searches of databases and registers only.

Fig. 1
figure 1

PRISMA 2020 flow diagram for new systematic reviews which included searches of databases and registers only


This study examines air ambulance preparedness criteria in different countries. Of the nine final papers, seven were quantitative and analyzed air preparedness during disasters and incidents using questionnaires and checklists. The other two papers were qualitative and utilized interviews with HEMS experts and beneficiaries. Most studies were conducted in Norway, including three. Subsequent studies were conducted in other countries, including two in the US and one each in Iran, Germany, Japan, and Poland. After analyzing and extracting data from the final studies, six categories of preparedness factors were identified: human resources, training and practice, management, instructions and standards, equipment, and structure.

Human resources

HEMS personnel should have been adequately prepared both mentally and physically before responding to any situation. Studies suggest that emergency department personnel may experience distractions from worrying about their families during disasters, which could impact their focus and accuracy in caring for injuries. They should be able to communicate with them by telephone to be aware of their health and do their duties calmly [15]. It was also proposed to create a way to address the health and welfare of personnel’s families in all their programs during a regional incident or to timely transfer information to the responding personnel. This design relieved the anxiety of personnel and allowed them to focus on their duties [16]. HEMS is a limited and expensive resource that requires very skilled and trained personnel [15], so doing an entire scientific evaluation of its use and its potential benefits is so important and essential in incident management. The most important component of preparedness during incidents is to hold maneuvers and exercises [17].

Training and practice

The leading role of training in the enhancement and preparedness of personnel is very important, and all the studies showed that it is one of the points to be prepared for before disasters occur. Therefore, the issue of training and practicing is one of the leading points that the staff should be trained with essential practices based on increasing their ability against disasters before their occurrence. They should at least participate in this training once a year, and managers should make arrangements to provide practice and have HEMS staff participate in it. Being aware of other people’s experiences and using their learned lessons is more effective assistance for enhancing knowledge, awareness, and preparedness for disasters. Also, awareness, competence, and knowledge of personnel related to responding to injuries or disaster conditions and safety behaviors decrease. The exercises provide opportunities for operating, which are critical for preparing HEMS. Two parameters, including practice and time, are assessed for the exercises. Participation in emergency reaction practice is important because it can allow HEMS personnel to gain confidence in doing activities that may be required for a public health emergency or mass casualty incident, including situations not covered by policies and protocols. Participating in HEMS has several advantages in terms of planning and practicing emergency reactions. Firstly, participation in the planning of an exercise can familiarize emergency management staff with proper roles in HEMS while identifying what functions cannot be suitable or which of them require the development of new policies and protocols. Emergency responders and incident commanders should know that the required service should be supported by policies and protocols. These should be clarified and communicated to all staff [18]. HEMS is a limited and costly system that needs skilled and trained staff. So, doing an entire scientific evaluation is essential to its use and its potential benefits [17].


HEMS is an integral part of the management and planning of important incidents in many countries [17]. The performance of comprehensive training programs is essential to effectively managing the HEMS process during disasters such as earthquakes through integrated management. These programs include the formulation of a written and comprehensive training program; priority of the preparedness program; coordination between the fields involved in the incident; developing infrastructure; efficiency of the triage process; attention to training rules and safety instructions and efficient training; a comprehensive communication process; attention to the supply and maintenance of human resource specialized equipment; access to the skilled and specialized workforce; awareness of experiences and learned lessons; optimal planning; writing HEMS preparedness programs to be responded during disasters; process-oriented preparedness; systematic approach for caring the patients; supply and maintenance of specialized equipment; access program to the skilled and expert workforce; enhancing internal motivation of personnel; holding educational courses of how to communicate with medical teams; preparedness to create emergency operating center and air traffic control center; skilled pilots to fly in bad conditions, familiarity of nurses; and flight engineers, and pilots with the protocols for transferring patients [19].

HEMS mostly helps with treatment, triage, patient transfer, equipment, and staff. Lack of communication and insufficient air traffic control are also challenges when responding to disasters. More training and a focus on coordination, communication, and cooperation are required. So, air operating management provides essential information to manage optimal operations between helicopters, operating bases, and disaster management centers [20]. This system has three main functions: (1) sharing information between the helicopters and disaster management centers; (2) interface between humans and machines, i.e., internal and land terminals to enter and display information; and (3) optimal operating management that can help the human decision [20].


Based on this, two papers about COVID-19 emphasize more PPE, gloves, repellent liquid, long-sleeved clothing or other protective clothing, eye protection and an FFP3 mask, disinfectant devices, and materials that should exist in the air ambulance department [21, 22]. PPE allows safety work in a large incident area with the dangers of a normal scene [23]. HEMS equipped with PPE is very critical when caring for patients suspected of or confirmed by COVID-19. Therefore, a suitable PPE is recommended. Cleaning and disinfecting airplanes upon arrival at their home base is so important [23]. If air ambulances and airplanes have not been disinfected as much as possible before the next mission, then healthcare providers and transferred patients are exposed to a high risk of infection. Therefore, having disinfectant equipment and facilities is very important. Also, clothing and full PPE equipment should be utilized to prevent the transformation of COVID-19 and minimize the risk of infection among medical personnel. Moreover, the crew is likely to use precautions such as isolating patients or creative solutions during inter hospital transfers and longer emergency missions. The importance of using patient isolation units has been highlighted for transferring patients between hospitals and admitting them to emergency hospitals when the COVID-19 situation is unknown [24]. The danger of transferring viruses and the total state of infection and health are due to a lack of information about the infection and limited resources on the helicopter and plane, more than the health care providers in the hospital. Hence, cleaning and disinfecting ambulances and helicopters, having proper PPE, having air conditioners in the helicopters, and having access to PPE are essential [23].

Instructions and standards

Written policies, training for incident and triage commanders, participation in natural disaster exercises, air and land communication design, managing critical incident stress, annual addresses, and sharing surveys are all essential criteria that can significantly affect a medical program’s preparedness, reaction, and recovery in the face of disasters [16].

Protocols, guidelines, and programs for responding to disasters should be prepared and identified before these events occur to reach a comprehensive and integrated standard for treatment and dispatch because speed of action and quick medical actions are the first terms of responding to such events [15]. Access to additional information is important during these incidents. For example, the number of injured and the incident distance to the establishment of helicopters and their landing place, as well as their distance to the hospital, should be considered. Also, information resources can be obtained from the local police, firefighting, and HEMS departments.

Having the policy to overcome disasters means having a written policy based on the essential and key subjects, such as developing critical policies for preparedness during disasters as a first step; necessity for facilitating effective interaction with others; training and practicing at least once a year; zero hour exercises; reviewing policies once a year; publishing policies timely (along with updating, preparing instructions for responding to disasters, HEMS, stress management, incident command training, air and land communication program, stress management of critical incidents, and sharing policies [16].

In the structure, the most important issue is to determine the data content and format while designing the equipment for sharing information, including coordination between the establishment of helicopters around the country, efficient cooperation between organizations, reaction to the broad area disaster, systems for fueling, and efficient maintenance, frequent and unnecessary missions, crowd radio communication in the air, land, operations, and bad weather conditions [20]. And, creating helicopter pads in urban and intercity distances and reducing the high costs of air emergency service [19].

Policymakers should pay a great deal of attention to incidents and disasters because such incidents can occur whenever and wherever. Based on the costly HEMS, the government’s financial supply can resolve many problems with equipment and preparation for air emergencies. Different studies have reported relatively similar factors to explain preparedness for incidents and disasters. The results of this study can formulate a comprehensive tool to assess HEMS preparedness during disasters and incidents.


One limitation of this study is that it only utilized English papers.


1) A comprehensive educational plan for effectively managing the process of air ambulances during disasters.

2) Interdisciplinary educational programs about the scenarios focus on cooperation and communication.


The results obtained from this systematic review provide a total view of the factors affecting the preparation of the air ambulance during disasters and incidents. It is recommended that senior managers and policy makers use the findings of the present study to identify the factors which affect preparedness of HEMS in disasters and take the necessary measures to eliminate to obstacles.

Data Availability

The datasets generated and/or analysed during the current study are not publicly available due to the necessity to ensure participant confidentiality policies and laws of the country but are available from the corresponding author on reasonable request.


  1. Search and Rescue.



Helicopter Emergency Medical Service


Emergency Medical Services


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The authors acknowledge and thank all the participants in this study.


This research did not receive any specific grant from funding agencies in the public, commercial, or not for profit sectors.

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MH was involved in the conception and organization of the study. MAM, MB, and MP, were involved in the execution and data collection of the study; MH, MB and MP, participated in statistical analysis design and/or execution. All authors contributed to the preparation, critical review and all of them approved the final manuscript.

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Correspondence to Mahmoudreza Peyravi.

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The present study was conducted in terms of the principles of the revised Declaration of Helsinki, which is a statement of ethical principles that directs physicians and other participants in medical research involving human subjects. The participants were assured about their anonymity and confidentiality of their information. Moreover, the proposal of this study was approved by the Ethics Committee affiliated with Shiraz University of Medical Sciences (SUMS), Shiraz, Iran with the code of (IR.SUMS.NUMIMG.REC.1402.009).

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Hatami, M., Marzaleh, M.A., Bijani, M. et al. Factors affecting the preparedness of Helicopter Emergency Medical Services (HEMS) in disasters: a systematic review. BMC Emerg Med 23, 135 (2023).

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