Next Refugee Health Crisis May Be Chronic, Climate-Driven, and Understudied

More than 120 million people were forcibly displaced in 2024, including refugees, asylum seekers and other displaced groups, a population whose health needs stretch far beyond emergency care to include trauma, chronic disease, maternal health, infectious disease, environmental risks and long-term access to health systems. A new bibliometric review published in the International Journal of Environmental Research and Public Health shows that global health research on forcibly displaced populations has expanded over the past two decades, but not always in the areas where future health pressures may be most severe.

The study, titled "Global Health Research on Refugees and Other Forcibly Displaced Populations: A Bibliometric Analysis from 2000 to 2024," was authored by Zaid Ahmed Shaik of Drexel University, and Noor Fathima Shaik and Aba Barden-Maja of the Hospital of the University of Pennsylvania. It analyzes 1,590 PubMed-indexed publications to map how research attention has shifted across time, themes, methods and geographies and finds that the field is growing, but major gaps remain in chronic disease, climate-related health, longitudinal research and underrepresented displacement regions.

A Research Surge Driven by Crisis, Not a Stable Global Agenda

Refugee and displacement health research did not grow evenly over the 25-year period. Publication output rose modestly from 2000 to 2013, with an average annual percentage change of 1.49 percent. It then surged sharply between 2013 and 2017, with annual growth reaching 42.49 percent, before slowing to 10.10 percent from 2017 to 2024. The authors link this rise to major humanitarian crises, especially the Syrian civil war, while cautioning that their descriptive design can show temporal associations but not prove direct causality.

The pattern matters because research attention often follows visibility. When a crisis dominates global headlines, funding, publications and institutional focus may rise. But displacement settings that receive less international attention can remain under-studied even when their health needs are urgent.

The study shows how the geographic focus of research shifted over time: earlier publications often mentioned Southeast Asian countries such as Vietnam and Cambodia, East African countries such as Tanzania and Uganda, and Balkan contexts including Kosovo, Serbia and Bosnia and Herzegovina. From 2009 to 2015, Afghanistan and other Middle Eastern contexts gained more attention. From 2016, research increasingly focused on people displaced from Syria, while the early 2020s saw more studies on Rohingya people and Ukrainian refugees.

For policymakers and funders, the challenge is to build a displacement health research agenda that is not only crisis-responsive but also anticipatory. Health systems need evidence before crises become unmanageable, especially as conflicts, climate shocks, political instability and economic distress continue to drive protracted displacement.

Mental Health Leads, but Long-Term Illness Is Falling Behind

Nearly one in three publications, 31.45 percent, focused on mental or psychosocial health, followed by health policy and systems at 26.04 percent, children and youth at 22.39 percent, infectious disease at 15.66 percent, and maternal and reproductive health at 11.07 percent. These priorities reflect real and urgent needs. Forced displacement often exposes people to violence, loss, family separation, uncertainty, disrupted education, legal insecurity and barriers to care. Mental health research is therefore central to any serious public health response.

Non-communicable diseases accounted for only 8.74 percent of publications, while environmental and climate-related health represented just 1.51 percent. Many displaced people live for years in host communities, camps, informal settlements or unstable urban environments. Over time, the health burden expands from immediate trauma and infection risks to diabetes, hypertension, cancer care, dental health, heat exposure, air quality, wildfires and other environmental threats. The paper's thematic table identifies non-communicable disease subtopics such as diabetes, hypertension, dental care and cancer, and environmental/climate subtopics such as air quality, heat extremes and wildfires, but these categories remain among the least represented.

Refugee health cannot be treated only as an emergency package of vaccination, infectious disease control, trauma care and maternal support, although all remain essential. Host-country health systems must also prepare for chronic disease management, continuity of medication, disability-inclusive care, climate-sensitive health planning and primary care integration. For developing countries and Global South host communities, where health systems may already be under-resourced, this gap is especially consequential. Without better evidence on long-term and climate-linked health needs, policies risk underestimating the true cost of displacement.

Evidence Is Growing, Yet Too Much of It Still Reviews the Past

Review articles accounted for 64.15 percent of the literature, far exceeding comparative studies at 13.14 percent, randomized controlled trials at 8.05 percent, meta-analyses at 5.41 percent and observational studies at 3.46 percent. Clinical trials, comparative studies, observational studies, feasibility or pilot studies, and randomized controlled trials together covered approximately 3,012,698 patients, but the overall field remains heavily weighted toward synthesizing existing knowledge rather than generating new primary evidence or testing interventions at scale.

The authors offer an important explanation: conducting primary research among forcibly displaced populations is difficult. Ethical constraints, mobility, data access problems, heterogeneity across populations and protection concerns can make intervention-based and longitudinal research harder to design and implement. Still, the dominance of reviews signals a problem for evidence-based policy. Reviews help organize knowledge, but they cannot substitute for stronger data on what actually works in different displacement settings.

International organizations, development agencies and research funders can support ethical longitudinal studies, implementation research, community-led designs and intervention trials that follow displaced people over time. They can also invest in local research capacity in host countries, rather than concentrating scholarship in a small number of high-income institutions. The study reports that authors most commonly came from the United States, United Kingdom, Australia, Canada and Germany, while leading institutional affiliations included Johns Hopkins University, the University of New South Wales, Harvard University, the University of Toronto and Columbia University.

Displaced communities, local clinicians, national public health agencies and Global South researchers must have a stronger role in defining priorities, interpreting findings and designing interventions.

Following People Beyond Emergency Response

The analysis relies on PubMed, which likely overrepresents biomedical research and high-income-country scholarship while excluding some social science, regional and humanitarian databases. Its search strategy focused on titles and abstracts, which increases precision but may miss studies where displaced populations are discussed without being named prominently. The authors also note that the search terms may not capture all forcibly displaced groups, including some stateless people and Palestinian refugees under the United Nations Relief and Works Agency for Palestine Refugees in the Near East. Although the study did not filter by language, 95 percent of included studies were written in English, introducing language bias.

That said, the limitations do not weaken the study's relevance; they sharpen it. The paper is not a complete map of all global knowledge on displacement health, but a map of what is visible in one major biomedical database under a conservative search strategy. The visibility matters because databases shape what policymakers, researchers and funders find when they look for evidence. If important regions, languages, disciplines and health risks are underrepresented, they may also be underfunded and under-prioritized.

The next phase of refugee health research must therefore be broader, deeper and more inclusive. It should:

• expand beyond PubMed to include humanitarian, regional, policy and social science databases.
• include more non-English literature and more studies from underrepresented regions, including South and Central America, which the authors identify as a gap.
• move beyond short-term crisis snapshots toward longitudinal evidence on people who remain displaced for years.
• give greater attention to chronic disease, environmental health and climate-related risks - areas the paper identifies as underexplored despite their growing public health significance.