Population groups that have limited access to health care, food, housing, employment, and other basic life necessities are considered vulnerable. These vulnerable populations are less equipped to cope with the risks of poverty and disease due to their lower social status. Vulnerable populations include women, children, the elderly, members of religious and ethnic minority groups, indigenous people, individuals with physical or mental disabilities, refugees, people living in remote rural areas, and those living in urban slums.

Vulnerable populations are typically on the periphery of mainstream health systems, leading to poor access to medical care and disease prevention. These populations face a higher incidence of disease and illness and increased disease mortality. For instance, children from poor and rural communities in developing countries are two times more likely to die under the age of five when compared to their richer counterparts in the developed world. In the United States, African Americans and Hispanics have a much higher rate of human immunodeficiency virus (HIV) infection and acquired immune deficiency syndrome (AIDS) than the white population.

Social determinants of health for vulnerable populations put them at a higher risk of negative health outcomes. Determinants include the social, economic, and physical conditions where people live and work. The distribution of resources, power, and wealth impact these conditions. The World Health Organization (WHO) identifies poor social determinants as a primary cause of health inequality within and between countries.

Organizations such as Médicins Sans Frontières (MSF; Doctors Without Borders) have programs aimed at meeting the basic health needs of vulnerable members of society, including reaching victims of war, natural disasters, and other calamities. The United Nations (UN) World Food Program supplements the nutritional needs of vulnerable children through its school-feeding program. The WHO highlights the plight of indigenous people who have the highest rates of suicide, diabetes, infant mortality, and other health-related issues. Educating policy makers and leaders about the realities facing vulnerable populations is considered an important strategy for improving health outcomes.

Attention to the health issues facing vulnerable populations can be traced back to the Lalonde Report published in Canada in 1974. Prior to the report, health care followed the medical model of researching and treating diseases. This seminal work proposed looking at other determinants of health including lifestyle choices, human biology, and social and physical environments where people live. Additionally, the report suggested interventions to improve public health should focus on those population groups with the highest level of risk for certain diseases as determined by large-scale studies. These included focus on those who smoke, drink alcohol, or have high blood pressure. The report considered these risk factors to be due to choices made by individuals. This populations-at-risk model was successful in bringing awareness to the health risks associated with certain behaviors and lifestyles.

Critiques of the populations-at-risk model maintained that this approach would lead to victims being blamed for the health conditions they experienced, which would lead to stigmatizing certain population groups. Secondly, there was a critique that intervention aimed at these population groups would not address the root problems and societal forces that lead members to participate in high-risk behaviors. An alternative to the populations-at-risk model was the population model discussed in the Strategy of Preventive Medicine by Geoffrey Rose, first published in 1992. The strategy population model was to focus public health interventions toward the entire population instead of focusing on high-risk individuals.

Population level interventions are weak because they lack focus on those with the highest risk of developing Page 667  |  Top of Articlenegative health outcomes. A population model approach may increase health inequities, particularly if those who are most at risk of suffering health problems do not receive the interventions they need. Katherine Frohlich and Louise Potvin argued in 2008 that vulnerable groups within a population face shared social characteristics, increasing their risk of experiencing negative impacts from environmental, biological, or other health threats. This vulnerable populations approach called for a focus of public health intervention toward root causes of health problems. These include increasing socioeconomic status and improving education.

 
An elderly man is treated at a relief camp established by the Pakistani navy for flood-displaced victims after a flood hit Sind Province in Pakistan. The elderly are one group considered vulnerable, and they may be at increased risk during events such as natural disasters. © Asianet-Pakistan/Shutterstock.com. © Asianet-Pakistan/Shutterstock.com.

Economic inequality is one of the primary drivers keeping vulnerable populations from accessing the medical and social services they need to decrease health risks. Those in poverty and on the fringes of society are often desperate to find the resources to survive each day. The desperation caused by poverty may further put people in harm's way. Poverty can exacerbate domestic problems and violence. Children are often not in school, instead they help the family increase income or food production, making cycles of poverty difficult to break.

Government policies and programs must recognize the needs of the most vulnerable and improve access to vital services. Interventions are needed to improve access to health-care services, education and job skills training, and community support and awareness of the plight of vulnerable people. A number of nongovernmental organizations, including international organizations, recognize the difficulties vulnerable groups face. The UN Population Fund identifies a life of health and equal opportunity as a right for every woman, man, and child.

Vulnerable population groups face physical, psychological, and social disabilities. Those with physical concerns include the chronically ill, disabled, people living with HIV/AIDS, and mothers and infants. Psychological concerns include those with chronic mental conditions, such as schizophrenia, depression, suicidal tendencies, Page 668  |  Top of Articleand substance abuse. Social related difficulties encompass those experiencing abuse in the family, the homeless, immigrants, and refugees. Vulnerable groups often face issues in each of these categories, which further complicates the health concerns they face.

 
A child does her homework while her family works at a landfill in Kathmandu, Nepal. Nepal is one of the poorest countries in the world, with more than one-third of children living below the national poverty level in 2010, according to the United Nations Children's Fund. © De Visu/Shutterstock.com. © De Visu/Shutterstock.com.

Women are a vulnerable group throughout the world due to gender-based discrimination that results in social and economic barriers that may limit their ability to access goods and services necessary to maintain their health and well-being. Approximately half of the women in developing regions receive the recommended amount of health care they need. Treatable complications from pregnancy and childbirth kill more than one woman every two minutes in the developing world. For each woman that dies, another 20 to 30 women have serious or long-lasting complications. Surviving children are also at risk for increased poverty and poor health outcomes when they lose a mother or a mother is disabled.

The Millennium Development Goals (MDGs), a coordinated effort begun in 2000 by the UN to focus on identified priorities, set the goal of reducing maternal mortality 75 percent from 1990 levels by 2015. While the reduction has been significant, at 45 percent in 2015, the goal was not reached. To further improve maternal health, improvements need to be made to increase access to skilled nursing personnel during delivery. Also, all women need access to reproductive health services and prenatal services. There is a lack of resources available to provide the specialized care women need.

There are a number of international organizations and programs working to advocate for women and the health-care challenges they face. One nongovernmental organization, Partners In Health (PIH), considers health care a human right for both men and women. PIH works to meet the specific health and cultural requirements of women in the communities where they are present. They provide trained health workers in the remote mountains of Lesotho, in southern Africa, to give the health care women need before, during, and after pregnancy and birth. PIH also addresses the root causes of poverty and provides financial assistance to women for transportation to and from health clinics. They advocate for the needs of women and those in poverty.

The UN chartered an organization, UN Women, to draw attention to and improve the plight of women throughout the world. They support a more equitable distribution of resources, particularly credit, seeds, and information technology in agricultural areas around the world. Page 669  |  Top of ArticleWomen are vulnerable to abuse but are not empowered to speak out. UN Women assists in expanding economic opportunities for women, with a goal of improving women's sense of self-worth and societal respect for women.

 
A woman is examined at one of the refugee camps in Dadaab, Kenya, where thousands of Somalis have lived since the 1990s. © Sadik Gulec/Shutterstock.com. © Sadik Gulec/Shutterstock.com.

Refugees have typically been displaced from their home country to escape conflict or human rights violations. Although they may have escaped immediate conflict or violence, they are very vulnerable because the country in which they seek refuge may not protect their basic rights and security. They are particularly vulnerable, as there is a risk that the source of the violence, which could be their country's military, might still reach them. Displaced people often live in densely populated camps for extended periods in a state of instability, not knowing if and when they will return to their homes.

Providing for the health needs of displaced people is one of the primary focus areas for the UN Refugee Agency (UNHCR). The 1951 Refugee Convention says that refugees should have access to the same health services available to the citizens of the country of refuge. The top five causes of mortality for displaced children under the age of five are malaria, malnutrition, measles, diarrhea, and respiratory infections. The UNHCR works with partner organizations to provide nutritional support, immunizations, reproductive services, and monitoring of public health among refugee populations.

There are often particular vulnerabilities among displaced people, including victims of trafficking, people with disabilities, the elderly, and women and children, and those facing sexual violence. The protection of women and children includes providing safe access to basic needs such as food, water, and latrines. It is the responsibility of the UNHCR and other agencies to ensure vulnerable refugees receive the services and protection they need.

There were 1.7 million Syrian refugees in Turkey in March 2015 due to violent insurgents in the region. Many of the refugees arriving in Turkey were women, children, and the elderly, who had to walk over rough roads with luggage. The elderly and disabled unable to walk had to be carried.

 
A Syrian woman and child sit outside a tent at a refugee camp on the Turkish-Syrian border. The United Nations High Commissioner for Refugees (UNHCR) estimates that of the 1.7 million Syrian refugees in Turkey in March 2015 about half are children. © Dona_Bozzi/Shutterstock.com. © Dona_Bozzi/Shutterstock.com.

There are approximately 100 million children living in the streets of urban areas throughout the world. Children may spend their days on the streets begging for food or money to help their families survive. Other children have no families, and call the streets their home. It is not uncommon for girls on the street to become pregnant and give birth to additional street children. Street children often band together in large groups for support and means of survival. Street children engage in begging, shoe shining, collecting trash, and prostitution, increasing their risk of sexually transmitted diseases, to find the resources to survive.

Poverty is the primary reason children are on the streets. In some cases a child's parents may have died due to conflict or disease, such as HIV/AIDS. Natural disaster and civil unrest are also reasons families separate. Other times, sexual abuse, or other social stigma, may force children away from their homes.

Children face many risks when living and work in the streets. Street children are vulnerable to physical health problems, violence, depression, and social discrimination. Police forces victimize street children. Substance abuse is common among street children. The WHO reports that the rates of disease morbidity, mortality, and disability are high among street children. Many street children receive little or no formal education.

The WHO has a street education program to improve the well-being of children on the streets. Education includes reading programs, counseling about substance abuse, teaching how to prevent sexually transmitted diseases, and guiding children to seek assistance for health and social problems. Other programs focus on teaching children life skills so they can better earn an income. Depending on the circumstance through which a child ended up on the streets, it may not be in the best interest of the child to return.

Individuals with mental health disabilities are particularly stigmatized and discriminated against in societies throughout the world. These individuals experience high rates of physical and sexual abuse. It is not uncommon for mentally ill people to be restricted from accessing social and medical services, including emergency care. It is also difficult for people with such disabilities to attend school, and they have limited employment opportunities. Page 671  |  Top of ArticleThese complex factors lead to higher rates of disease, and shorter life spans compared to rates in the larger population.

The WHO points out that many vulnerable groups targeted for intervention programs often suffer from mental disabilities. For example, many refugees fleeing violence in a country are likely to suffer from post-traumatic stress. Up to 67 percent of HIV/AIDS patients also suffer from depression. More than 50 percent of homeless people suffer from a mental health disability. Mental health issues are typically not addressed in intervention programs, and it is not uncommon for those with mental health problems to be excluded from programs.

The UN Convention on the Rights of People with Disabilities entered into force in 2008 to address the serious concerns facing this vulnerable group. The WHO has identified a number of evidenced-based strategies that should be integrated into development and assistance programs to address the needs of people specifically with mental disabilities. The goal of these measures is to improve outcomes for patients, families, and their communities.

First, services for mental health must be integrated into all health services, including at the level of primary care. Second, mental health issues must be considered at the broader health policy level. Third, in times of emergencies and crises, mental health services should be provided. Fourth, social services and housing development should consider mental health problems, so people receive the support services they need. Fifth, schools need to integrate mental health issues, and provide support to people with mental disabilities, helping them to access education. Sixth, the mentally ill must receive support to find employment opportunities. Seventh, laws and policies to protect the human rights of people with mental disabilities need to be developed. Eighth, those with mental issues should be enabled to engage in community and public affairs. Finally, development organizations should design programs to bring those with mental illness into decision-making processes.

Vulnerable populations exist in both developing and developed countries. According to the 2010 U.S. Census, approximately 36 percent of the U.S. population Page 672  |  Top of Articleidentified with a racial or ethnic minority group. Minorities in the United States experience a higher rate of preventable disease, death, and disabilities than do whites. The U.S. Centers for Disease Control and Prevention (CDC) explains that health disparities exist in the United States based on gender, sexual identity, age, disability, income level, and geographic location.

The CDC says influences on health include access and availability of quality education, healthful food, adequate housing, reliable and safe transportation, health-care providers who are culturally sensitive, health insurance, and clean water and air. The CDC facilitates the creation of policies and programs to reduce health inequities. It regularly chooses new public health topics on which to focus its resources. Focus areas are chosen only if they are highly related to premature death and disease burden, are distributed unequally to vulnerable groups, and have feasible interventions. Current topics include increasing access to more healthful food retailers, decreasing HIV transmission, and reducing work-related injuries.

The WHO member states adopted the Rio Political Declaration at the 2011 World Conference. First, the declaration calls countries to adopt improved governance for health and development, particularly recognizing the needs of vulnerable population groups. Second, it recognizes the need for community participation in health-related policy making. Third, it highlights a commitment for reorienting the health-care sector toward reducing inequity. Fourth, it calls for strengthened global attention and collaboration toward the social determinants of health. Finally, the declaration calls for improved monitoring and accountability of health inequities.

The MDGs and the UN Development Group have a strong influence on the development priorities addressed by governments and development organizations throughout the world. They recognize that development improvements achieved from 1990 to 2015 did not reach the most vulnerable groups. Through the development of new goals and strategies, it is recognized that governments need the capacity to recognize and address the health and poverty concerns of the most vulnerable groups.

The Robert Wood Johnson Foundation (RWJF), a large think tank on public health issues in the United States, includes the role of the social determinants of health when considering the health outcomes of vulnerable populations. RWJF promotes research to improve public health outcomes for vulnerable groups, including minorities, victims of abuse, and immigrants. RWJF engages stakeholders, policy makers, business leaders, and community groups while researching solutions to U.S. health issues.