Armed conflict, natural disasters, and forced relocation are among the humanitarian problems affecting hundreds of millions of people worldwide (1, 2). Almost 80 million people have been evicted from their homes against their will (3), and one in every six children lives in or near a combat zone (4). Humanitarian emergencies may arise due to natural disasters (e.g., earthquake in Syria and Turkey) and manmade/technological disasters (e.g., Ukraine, Russia, Yemen, Syria, and South Sudan) (4). Also, humanitarian emergencies may be indicated in cases of forced displacements, as evident with the inflow of refugees into Lebanon and Bangladesh, and could be internal displacement, as seen in the Democratic Republic of Congo, Ethiopia and most recently, Cameroon (2). Additionally, complex emergencies (co-occurrence of natural and manmade) may necessitate urgent humanitarian emergencies to curb immediate and future public health issues (2). Complex emergencies can occur when there is a breakdown in authority, an attack on a critical location, looting, numerous other conflict situations, or even wars (2). Some countries are coping with many crises simultaneously or protracted crises that have lasted for decades (5).

Few studies have examined the difficulties in forming solid and balanced research partnerships, despite the limited or lack of research in such settings being widely discussed over the past decade (6). Methodological constraints, ethical concerns, security issues, and logistical challenges have been identified as the main barriers to conducting research in such settings (7). Populations affected by conflict and other crises confront a variety of humanitarian issues and demands, such as population relocation, family separation, food shortages, a lack of health care, and increased susceptibility to outbreaks (8, 9). The term “health research in humanitarian crises” refers to medical research during humanitarian crises and/or research on a crisis-inflicted population (such as a population of refugees who have fled a violent conflict and have been relocated to a more peaceful area) (10). Collaboration with humanitarian organizations is crucial if research findings are to be implemented and incorporated into humanitarian policies and procedures; this is particularly important to address logistic and security difficulties (11).

Humanitarian needs are numerous and varied (1). Research in humanitarian situations is gaining traction and is now a worthwhile endeavor that permits the generation of contextually suitable knowledge to respond to the needs of those impacted by humanitarian disasters (1). Health research is necessary to guarantee that humanitarian response to disasters is evidence-based, effective, and establishes the foundation for post-crisis health planning, implementation, and evaluation (1, 4). It is believed that it is unethical to refrain from undertaking research in war and crisis circumstances, but contextual-based research is needed to help manage these crises (4). For instance, developing information and evidence about how to best care for children in emergency situations is vital (4). Children are being displaced and caught up in wars in greater numbers every year. They are the most vulnerable to climate change and environmental deterioration and frequently face famine risks (12). Children are increasingly confronted with long-lasting crises and unstable environments. Since 2010, United Nations Children's Fund (UNICEF) has responded to 300 humanitarian emergencies annually in around 90 countries (12).

Research can be used to understand and address problems in humanitarian settings (12, 13). Given the busy environment in which many humanitarian workers work, practitioners will be aware of these to some extent based on their experience, but given that, there is frequently little time to fully absorb the most recent conversations among practitioners, academics, policymakers, and civil society (13). This knowledge gap can be filled through research in the field, which will also assist practitioners in staying up to date with ongoing discussions about development and humanitarian aid (12). Researchers play a crucial role in translating complex information, such as observations, derived learnings from settings, research evidence, and specialized terminology, into a format that can be easily understood by practitioners and decision-makers who may not have an academic background or familiarity with academic traditions (11–13). Neglecting to utilize the knowledge gained from humanitarian contexts to enhance practice and services would be a missed opportunity (13, 14). However, it is important to emphasize that research should uphold ethical principles and avoid exploiting the vulnerability of individuals in these settings, aligning with the guidelines laid out in the Helsinki Declaration (13–15).

Humanitarian crises are made more vulnerable by inequalities and hierarchies in age, gender, social class, religion, and race because they restrict individuals from achieving their fundamental needs, accessing resources, and asserting their rights (14). Power asymmetry between research and study participants is heightened in these settings because of the several needs of individuals in these settings (15). Since the vulnerability needs to be investigated, especially in humanitarian settings, many researchers find themselves using a vulnerable population (15). For instance, research may be required to comprehend the vulnerability, address the therapy of, enhance the environment for, or alter policies in support of a specific ailment (14).

When it comes to receiving humanitarian relief, vulnerability—situation of being susceptible to physical or emotional harm—becomes a tool for human agency and a negotiating chip (16). Vulnerability can therefore influence social behaviors in a beneficial way. During humanitarian crises, one should act in ways that promote more openness and allow disadvantaged groups access to public spaces, especially when the impacted people is working together to rebuild their society (16). The condition of human interdependence, relational life, ties to others, and shared humanity is described here as vulnerability (17). Understanding the people, especially vulnerable populations, is crucial for reacting to humanitarian crises (12). Therefore, vulnerable groups should be involved in robust research that can ultimately increase their living condition and quality of life.

Community engagement is the act of interacting with and through groups of people who are connected by proximity, shared interests, or similar circumstances in order to address issues impacting the welfare of the populace. Community engagement is an effective tool for behavioral and environmental change to improve residents' and neighborhood's health (17–19). Partnerships and coalitions with relevant key humanitarian players are frequently employed in this process because to their capacity to mobilize resources, influence systems, alter partner relationships, and function as catalysts for changing programs, policies, and practices (18, 19). Bain et al. (20), proposed a framework for effective community engagement in research. They suggested some key elements of community-engaged research such as mutual respect, community motivation, community empowerment, and co-creation of interventions with communities, adherence to appropriate ethical principles, and gender mainstreaming. Table 1 shows barriers, facilitators and the reasons for community-engaged research in humanitarian settings as well as key recommendations.

In humanitarian settings, there is the lack of quality data, and most studies are cross-sectional, which makes it extremely difficult to address causality. Most interventions implemented in these settings are inappropriate, as they are not grounded in any solid evidence (unethical). Obtaining parental consent/assent to carry out research among adolescents in humanitarian settings can be extremely difficult. It is another question knowing if true consent is easily obtainable in these settings, as persons might be intentionally or unintentionally “coerced” to participate in research (e.g., transport and time compensation, or fear of being named and not receiving services, especially if the research agenda is NGO driven). Researchers need to be particularly trained to understand the broader meanings of consent within these contexts. Ethics committees have their responsibilities to play. Indeed, the competence of research ethics committees in reviewing research protocols geared toward humanitarian settings needs to be strengthened. They can specifically seek to know how “true consent” will be sought from participants as a special requirement in the ethics applications. Conceptualization informed consent for humanitarian settings is an urgently needed but under explored area of research.

Research in humanitarian settings is essential and presents an opportunity to use setting-specific knowledge to improve practice. Hence, community engagement must be ensured through co-creating the research agenda from the inception, implementation, and evaluation of evidence-based interventions. Indeed, ownership, adaptation, and sustainability can only be achieved through effective community engagement in research in these settings. Core considerations like gender, ethics, and frameworks to adequately characterize context remain key. Ignoring effective community engagement predisposes to create new areas of inequalities, widen existing gaps, or aggravate the conditions of some already vulnerable groups. How communities in humanitarian settings should be effectively engaged in research is an important yet underexplored area of implementation science which is highly needed.

LB, CN, PN, OB, LA, OA, ID, GM, and EK were contributed equally and significantly to its creation. LB read and made the necessary edits on the manuscript. All authors reviewed the final draft and gave their approval.