A Global Perspective on Socioeconomic Determinants of Cardiovascular Health

Abstract

Cardiovascular disease (CVD) is the leading cause of mortality in the world. From 2005 to 2008, the World Health Organization (WHO) planned an initiative to reduce the mortality rate of CVD by 2030 by addressing health, finance, transport, education, and agriculture in these communities. Plans were underway by many countries to meet the goals of the WHO initiative. However, in 2020, the COVID-19 pandemic derailed these goals, and many health systems suffered as the world battled the viral pandemic. The pandemic made health inequities even more prominent and necessitated a different approach to understanding and improving the socioeconomic determinants of health (SDOH). WHO initiated a special initiative to improve SDOH globally. This paper is an update on what other regions across the globe are doing to decrease, more specifically, the impact of socioeconomic determinants of cardiovascular health. Our review highlights how countries and regions such as Canada, the United States, India, Southeast Asia, the Middle East, and Africa are uniquely affected by various socioeconomic factors and how these countries are attempting to counter these obstacles by creating policies and protocols to facilitate an infrastructure that promotes screening and treatment of CVD. Ultimately, interventions directed toward populations that have been economically and socially marginalized may aid in reducing the disease and financial burden associated with CVD.

Noncommunicable diseases (NCDs) became a global health concern as a cause of significant increase in mortality. A recent shift occurred in low-income countries (LICs) and middle-income countries (MICs) regarding the cause of mortality. NCDs have surpassed the communicable disease mortality rate. Cardiovascular disease (CVD) is the leading cause of NCDs and the leading cause of death globally, contributing to an estimated 17.9 million deaths yearly.¹ As CVD continues to rise worldwide, we must comprehend the social and economic influences that contribute to the emergence of risk factors, which affect clinical decisions about who gets screened and treated.

Sir Michael Marmot, a professor of epidemiology and public health, highlighted how common inequalities and social determinants of health (SDOH) among various countries make certain populations more vulnerable to acquiring NCDs, which ultimately created the foundation for world leaders to address these pressing issues.² In response, the United Nations (UN) created the Millennium Development Goals (MDGs) derived from the Millennium Declaration, signed in 2000, which included 8 goals that focused on combating poverty, hunger, disease, illiteracy, environmental degradation, and discrimination against women. In 2015, during the UN summit, the Sustainable Developmental Goals (SDGs) replaced MDGs, which were 17 goals that focused on 5 elements: people, planet, peace, prosperity, and partnership to support the sustainability of environmental, social, and economic aspects of social inequalities. Ultimately, from 2005 to 2008, the World Health Organization (WHO) launched an initiative to reduce the mortality rate of CVD by 2030 by addressing health, finance, transport, education, and agriculture in these communities.³ WHO summarized 4 universal behavioural risk factors across global regions that influence the development and progression of NCDs, including physical inactivity, tobacco use, alcohol use, and unhealthy diets. Although there are behavioural risk factors that contribute to development of disease, these factors are controlled mainly by SDOH, which influence individuals or groups of people positively or negatively. The current evidence supports an association between socioeconomic inequalities and NCDs.¹ WHO acknowledged that SDOH are responsible for a significant part of health inequities among and within countries. It was a call to action to improve the health inequities from the unequal distribution of global and national power, income, goods, and services, which leads to a toxic combination of poor social policies and programs, unfair economic arrangements, and political instability.³

Plans were underway by many countries to meet the goals of the WHO initiative, as summarized in Table 1, published in 2017.⁴ However, in 2020, the COVID-19 pandemic derailed these goals, and many health systems suffered as the world battled the viral pandemic.⁵ The pandemic made health inequities even more prominent and necessitated a different approach to understanding and improving the socioeconomic and SDOH.⁶

Table 1.

Summary of global action on determinant of health in 2017

Region	Plans
Europe	In September 2012, the Health 2020 (European Health Policy) was adopted by the 53 member states of the WHO European region in September 2012.
	To test the efficacy of actions to decrease health inequities, the European Parliament allocated funds to develop pilot projects.
North America
Canada	SDOH was declared a government priority by the Federal Minister of Health, with an SDOH team run by the Public Health Agency of Canada.
United States	Several acts were passed: 2010 Patient Protection and Affordable Care Act; Healthy People 2020; and the National Partnership for Action to address health equity and SDOH.
South America	SDOH was identified as a priority by the Union of South American Nations’ Council of Ministers of Health: the 2010 to 2015 Plan of Action, an Intergovernmental Commission on Health Promotion and SDOH, and Pan American Health Organization (PAHO) Strategic Plan (2014–2019).
	Many countries have a strong focus on social medicine, health equity and human rights, and Health in All Policies, which is longstanding.
North Africa	There were a number of initiatives implemented since the Commission on the SDOH 2005 to 2008 to improve the knowledge base in the region and to engage member countries. For example, country-level studies and knowledge sharing among academic institutions and nonprofit organizations have been done to advocate and engage governments in the issue.
Middle East	At the Eastern Mediterranean 61st Session Regional Committee in 2015, member states agreed a plan a regional consultation on reducing health inequities in the Eastern Mediterranean Region through actions on the social determinants.
Sub-Saharan Africa	To achieve health equity, the WHO Regional Office for Africa (AFRO) gathered stakeholders from 12 Eastern and Southern African countries in May 2013 to discuss how Health in All Policies can be implemented at the national level.
Asia	In addition, to address SDOH, The WHO Regional Office for the Western Pacific Region, Asia Pacific Global Action for Health Equity Network, and the Social Inequity Reduction Network advocated for addressing SDOH determinants of health beyond health sectors and strengthening capacities for health equity analysis and assessment of the impact on health.
	Most countries in both the Western Pacific and South East Asia have NCD strategies, and WHO recently focused its attention on supporting countries with SDOH strategies and universal health systems.
	To ensure improved focus on prevention rather than treatment, Healthy China and Healthy Cities were implemented to promote healthy lifestyles and physical fitness. China aims to achieve health equity by 2030 by using improving the health insurance system, prevention, and greater technologic advances.
Australia	In 2013, there was a change of government that caused health inequities—especially, SDOH to be removed from the political agenda—and major financial cuts to public sector spending have been implemented.

NCDs, noncommunicable diseases; SDOH, social determinants of health; WHO, World Health Organization.

As a result of the slow progress in addressing SDOH worldwide and the effect of the COVID-19 pandemic, in 2021, the 74th World Health Assembly adopted a new resolution on the SDOH.⁷ To advance health equity, WHO launched an 8-year Special Initiative for Action on the SDOH for Advancing Health Equity.⁸ The Initiative was to ensure that health equity is integrated into social and economic policies. Although the initiative deals with all health issues, CVD is a major component of health inequities that result from socioeconomic factors of health.⁶

This review will summarize the current literature on socioeconomic determinants of cardiovascular health. Data on the impact of socioeconomic factors that affect CVD from select parts of the world will be explored, representing different levels of income and health care systems. Continued inequities will be highlighted, and potential strategies to mitigate the risk of CVD will be discussed.

Socioeconomic Factors vs SDOH

The United States (US) Department of Health And Human Services’ Healthy People 2030 initiative groups divided SDOH into economic stability or socioeconomic status (SES), education, health care access and quality, neighbourhood and built environment, and social and community context.⁹ Socioeconomic factors and SDOH are not synonymous. They both significantly influence an individual’s well-being and health outcomes. However, they refer to different aspects of a person’s life and environment. Socioeconomic factors primarily focus on economic and social characteristics related to an individual or a population. These factors include income, education, occupation, and social class. Socioeconomic factors can directly affect an individual’s access to health care; ability to afford medical services; and lifestyle choices such as diet, exercise, and tobacco use. Lower SES is often associated with worse health outcomes because of limited access to health care, higher stress levels, poor diet, and increased exposure to environmental risks.⁹

On the other hand, SDOH encompasses a broader range of factors that influence health outcomes. They go beyond only economic and social factors and include environmental, cultural, and community-related aspects. These determinants include housing quality, neighbourhood safety, social support networks, exposure to discrimination, access to healthy food, climate change, and environmental pollutants. Social determinants emphasize the importance of the conditions in which people are born, grow, live, work, and age.² They consider the structural and societal factors that shape health disparities. They also highlight the role of policies, laws, health care systems, religion, disability, and social and economic inequities in shaping health outcomes. Thus, socioeconomic factors are only a subset of SDOH. Understanding both concepts is crucial in addressing health disparities and developing effective public health interventions.¹⁰ Figure 1 shows the components that influence SDOH.

Figure 1.

Social determinants of health (SDOH) and the different components.

Cardiovascular Disease: The Leading Cause of NCDs

CVD is a huge contributor to the rise in mortality of NCDs and is a group of diseases that include coronary artery disease (CAD), peripheral arterial disease, and aortic disease, and rheumatic heart disease (RHD). Figure 2 shows the increase in the number and percentage of deaths caused by CVD globally from 1999 to 2019. Throughout the 3 decades, there has been a 25.1% increase in CVD deaths in LICs and MICs compared with the year 2000 and a 43.4% decrease in the high-income countries (HICs) before the COVID-19 pandemic.¹¹

Figure 2.

Global burden of disease caused by cardiovascular diseases in both sexes, all ages, and percent of total deaths from years 1999, 2009, and 2019. The colour scale has been enlarged for better readability. The colour scale represents the percent of total deaths from cardiovascular disease, with dark blue indicating the lowest death rate, dark red the highest, and the continuous colour gradations between indicating the various percentages of total deaths.¹¹

A study from 72 countries using the ecological study method was used to find the association of socioeconomic, environmental, and health behavioural factors. The analysis showed that CVD and diabetes mortality were more concentrated in LICs and MICs and were negatively associated with the gross domestic product (GDP), the distribution of income among individuals, and the Western diet. These findings were explained as HICs had better access to health care.¹²

The CVD burden continues to rise in LICs and MICs, which is described as changing patterns of population distributions in relation to the evolving patterns of mortality, fertility, life expectancy, and leading causes of death. This process has been delayed in terms of economic and social development, hindering their ability to adequately prevent development and slow progression of disease. Consequently, changes in incidence rates and risk factors are accelerated and regularly outpace the evolution of health care systems, including health care networks, human resources, and infrastructure required to support the prevention and progression of CVD.¹³

In LICs, lower SES is associated with a higher risk of developing CVD and premature death. One study showed that a higher educational level correlated with a lower risk of development of CVD and mortality. Educational status substantially influences an individual’s income potential and occupational opportunity, indirectly affecting residential status. Residential status affects SDOH. This suggests that focusing on national policies to strengthen the educational system in areas with lower SES could drastically improve general health in a region.¹⁴

Creating policies that favour CVD prevention in the outpatient setting will offset the high inpatient cost and directly decrease the disease burden on vulnerable populations. Interventions directed toward increasing access to outpatient preventive care in economically and socially marginalized communities might aid in reducing the impact of CVDs.¹⁵

Countries have different health care systems that directly affect NCDs and CVD. We highlight some representative countries and regions and discuss what each is doing to decrease the negative effect of socioeconomic determinants of cardiovascular health. We discuss how various countries and regions, such as Canada, the United States, China, India, Southeast Asia, the Middle East, and Africa, are uniquely affected by various socioeconomic factors and how these countries and regions are attempting to counter these obstacles by creating policies and protocols to facilitate an infrastructure that promotes screening and treatment of CVD.

Canada and the Impact of National Health Insurance

Canada has followed a universal public health insurance model, termed Canadian Medicare, since 1966. This publicly funded model provides coverage for all citizens and permanent residents.¹⁶ This legislation was revised by the Canada Health Act of 1984, which created guidelines for medically necessary inpatient services and diagnostic and physician services. The federal and provincial plans cover approximately 70% of medical needs, including all inpatient services and prescription medications. The remaining 30%—including vision, dental, and outpatient prescription medications—are privately financed either through patient out-of-pocket payments or supplemental insurance from employers.¹⁷

Since its initiation, universal health insurance has significantly reduced poor outcomes related to medical emergencies, such as asthma or surgical emergencies, because of prompt treatment.¹⁸ However, the system is far from perfect. Although universal health care promises equal resources and health care access, significant inequalities continue to exist. Although differences in income-related health insurance coverage for medically treatable diseases were significantly reduced by universal health care, persistence and even growth in health care inequalities have been observed and attributed to SDOH unique in Canada indigeneity.^18,19

Although health inequities affect multiple diseases, differences in CVD are the most glaring. CVD is the most common cause of noncommunicable morbidity and mortality in Canada, accounting for 22% of deaths among LICs and MICs.¹⁹ Within Canada, there are significant differences in death rates from CVD among populations depending on their SES. Those with the lowest income had the highest mortality rates, with rates declining as income increased.^20,21 As expected, individuals with lower SES were less likely to have access to education on risk-factor management, treatments, and advanced health care, further slowing the rate of decline of CVD. Over time, this gap in exposure to risk factors and the development of CVD has been widening despite the promise of equal and universal health care for all.^19,20

Across all groups, perhaps the most affected by SDOH are the Indigenous Peoples in Canada. The Indigenous Peoples in Canada comprise 3 major groups: the Metis, the First Nations, and the Inuits^16,17 Multiple studies have reported significantly higher exposure rates to risk factors, diseases, and overall mortality in this group.¹⁵ Prevalence of CVD is also higher in Indigenous Peoples in Canada compared with non-Indigenous individuals in Canada. They have higher rates of exposure to cardiovascular risk factors.¹⁶ Aside from traditional risk factors, they are subject to higher rates of social disparity.²² The historical context and impact of colonial expansion play a significant role in the continued oppressive marginalization of the Indigenous Peoples in Canada and why they suffer from CVD disproportionately compared with non-Indigenous individuals in Canada. An example of this would be how Western biomedical perspectives influence health care decisions, which can lead to epistemic bias and exclusion of medical practices that can benefit the Indigenous Peoples in Canada.

Indigenous Peoples in Canada are relocating to urban areas, accounting for 52% of the general population. This was highlighted in the 2016 census, which confirmed that 62.6% of the Metis, 52% of the First Nations, and 56.2% of Inuit peoples resided in urban areas. Urban areas have been identified to have a higher per-capita density of primary health care, mental health, social support, and specialist health services. Despite the advantages provided by living in urban areas, Indigenous Peoples in Canada still suffer from higher rates of CVD disproportionally to non-Indigenous individuals in Canada because of difficulty obtaining adequate health care, resulting in poorer outcomes. The barriers that have been identified include difficulty communicating with health professionals, medication issues, dismissal by health care staff, wait times, mistrust and avoidance of health care, racial discrimination, poverty, and transportation issues.²³

Furthermore, Indigenous Peoples in Canada account for a large portion of the general population in Northern and remote territories. The gradient of inequity between Indigenous and non-Indigenous Canadians is likely affected by the limited access in the less densely populated areas.^22,24,25 This contributes to lower levels of education and poor health literacy and drives the development and exacerbation of CVD. In addition, these areas lack physicians and advanced health care. One study in 2017 showed that 92% of physicians practiced in urban locations. Although some provinces have rural practice initiatives, there are no national programs to ensure the presence of physicians in rural and remote northern areas. In the northern territories, primary care is often led by nurses.¹⁷

Finally, Indigenous Peoples in Canada view health holistically, including physical, spiritual, and emotional components. Government policy, which aimed to assimilate Indigenous Peoples in Canada into Euro-Canadian culture was insensitive to their views, a theme still present today and confirmed in the Truth and Reconciliation Report of 2012.^16,24 This has not only been harmful to their sense of identity and culture but has also resulted in social isolation and discrimination, which has widened the gap of health inequities in this population compared with Euro-Canadians. There is no simple solution for improving health equity, as there is an extensive history that must be recognized and understood to develop a multifaceted approach to address the current health disparities effectively among the underserved communities. However, implementing policies and programs that focus on culture, traditional healing, and Indigenous-led services can be the first step in eliminating these barriers.²³

Another group also affected by health inequities in Canada is immigrants. Canada is home to more than 8.3 million immigrants, making up almost one-quarter of the country’s population.^16,17 Although new immigrants initially tend to have fewer chronic conditions than Canadian-born people, called the “healthy immigrant effect,”²⁶ this difference disappears once they are exposed to a foreign country’s social, environmental, and cultural factors.²⁷ Previous research on health care access in the immigrant population has shown that recent immigrants are likelier not to have regular doctors, not report emergency conditions, and have more unmet health care needs than established immigrants. These issues are caused by complex factors including geographic and language barriers, difficulty navigating the health care system, and differences in cultural beliefs about health care. Language barriers are linked to medication errors, delays in diagnosis, suboptimal care, and poor therapeutic relationships with providers.²⁷ Although the health inequity gap narrows as immigrants become more established, new immigrants still face significant challenges navigating health care. However, compared with refugees, the voluntary immigrants, have a stronger “healthy immigrant effect.”²⁶

The health disparities driven by SDOH in Canada is an issue that is well recognized and researched, as there are multiple government documents and policies in place that address these gaps.²³ Marc Lalonde, former Canadian Minister of National Health and Welfare, published “A New Perspective of Health in Canada” in 1974.^25,28 This document was among the first to address that health disparities were driven more by social, economic, and environmental factors than biology and genetics alone. It implemented the idea of “health promotion” within Canada and advocated for preventing diseases more than treating them.^25,28 Since then, several such documents, surveys, and policies have been from HICs that report the influence of SDOH.

However, there is little information and guidance on implementing changes to fix the problem. Any strategies suggested focused on individual lifestyle choices. This places the onus on the individual and further underlines differences in education and health literacy.^19,25 For example, Gore and Kothari¹⁹ evaluated program initiatives in Ontario and British Columbia that address healthy living and health inequity. Although more than 60 initiatives exist in each province, most are lifestyle based, a few are environmental based, and even fewer are structural or systems based. Many provide a blue-print or resources for communities to build their initiatives to address the SDOH without actively implementing change.¹⁹ This tremendously burdens individuals and communities to address and mitigate the SDOH, causing health inequity.

United States: The Impact of the Affordable Care Act (ACA)

Health care costs in the United States have far over-shadowed those of other HICs. By 2021, the impact of health care spending reached up to $4.3 trillion or $12,914 per person, accounting for 18.3% of the entire nation’s GDP.²⁹ CVD is the leading cause of death in the United States, as it is estimated to be responsible for 610,000 deaths per year. It thus significantly burdens health care costs, accounting for 12% of the total US health expenditure in 2017 and 2018, surpassing all other major diagnostic groups.³⁰ The exorbitant cost of receiving health care services has long been a source of financial strain for Americans in all walks of life. Still, it has most significantly affected the poorest populations who already struggle with many factors that limit their ability to get adequate health care. The ACA was implemented in 2014 to address these disparities by expanding Medicaid qualifications and increasing funds for other health care initiatives. Since its implementation, 40.2 million Americans have been enrolled in ACA-related programs, representing a 219% increase in insured individuals.³¹

Health care disparities are most evident in African American and Native American adults, who are 2 and 1.5 times more likely to die of CVD or be diagnosed with CAD than their White counterparts, respectively.³² These disparities can be best explored through the lens of different SDOHs, which can be divided into 6 distinct domains: economic stability, education, food, neighbourhood and physical environment, community and social context, and health care system.³³ Each of these domains significantly affects people’s ability to receive medical treatment and be proactive in their health to mitigate CVD. Most of these factors have ingrained institutional barriers because of historical segregation policies, such as redlining laws, the consequences of which continue to reverberate to the modern day.³² We can see their impact, as they cause disparities permeating all aspects of SDOH. A study by Safford et al.³⁴ showed that individuals with 3 or more adverse SDOHs working against them were 67% more likely to have fatal outcomes of CVD. The intertwined nature of these SDOHs makes curbing the disparities these individuals face a particularly daunting challenge.

The ACA was established with several aims in mind: to increase insurance coverage through shared responsibility, improve fairness and quality in coverage, improve health care value and efficiency while reducing wasteful spending, make the health care system more accountable to diverse populations, and bring long-term changes to the availability of primary care and preventive health care.³⁵ To further promote preventive health care and address health care disparities, the ACA also allocated $11 billion to expand the services of Federally Qualified Health Centers, which function as a type of safety net for these underserved areas.³⁶ These provisions were not universally applied, however. Based on the 2012 Supreme Court ruling, each state was allowed to adopt these provisions. As of 2020, only 39 states, including the District of Columbia, have opted to take advantage of the expansions provided by the ACA.³⁷

Health insurance coverage is a large piece of the health equity puzzle, and the ACA has made large strides in helping more individuals get insurance. Uninsured individuals have been associated with a 1.65 times increased risk of stroke and a 1.26 times increased risk of CVD mortality.³³ By providing more people with insurance, there has been a decrease in uninsured visits and an increase in Medicaid-insured health care visits of about 60% in expansion states.³⁸

Health insurance expansion has been shown to provide benefits for CVD. A study directly compared expansion and nonexpansion states and showed that expansion states had 4.3 fewer deaths from CVD per 100,000 residents.³⁹ This improvement is likely a consequence of improved access to primary preventive care resources and screenings aimed at mitigating CVD risk factors, which were seen to improve after the implementation of ACA initiatives.⁴⁰ Although the ACA has improved overall CVD outcomes, there continue to be significant disparities when dealing with minority populations. Despite the ACA, Black and Hispanic individuals have uninsured rates that are 2 to 4 times higher than their White counterparts.³² Furthermore, Medicaid expansion was not associated with a decrease in Black-White disparity via age-adjusted mortality ratio. They noted that the 2 factors that have been shown to improve this disparity included the number of cardiologists per 100,000 residents and increased median household income, once again highlighting the institutional hurdles to health care access that play a part in SDOH.⁴¹

Furthermore, CVD has been identified as the leading cause of morbidity and mortality in women globally. In the United States, clinical research has unveiled biological differences (pregnancy, reproductive factors, and higher prevalence of systemic inflammatory diseases) between women and men and differences in their respective responses to external stressors, including social, environmental, and behavioural stressors (higher prevalence of anxiety and depression). The under-representation of women in biological research has stalled this process and hindered progress in women’s cardiovascular health (Call to Action for Cardiovascular Disease in Women: Epidemiology, Awareness, Access, and Delivery of Equitable Health Care: A Presidential Advisory From the American Heart Association).^42–44 In addition, before the initiation of ACA, insurance coverage could be denied for pre-existing medical condition such as pregnancy. The ACA promoted cardiovascular health in women by improving the uninsured women’s rate from 17% to 11% from 2013 to 2015 and reversing previous sex inequities by removing the 10% to 50% higher premium charge to women, including women beyond reproductive age (recent legislation, public policy changes, and women’s cardiovascular health).

Overall, the initiatives put forth by the ACA have had a tangible impact on access to health services and CVD outcomes in the United States. It has also provided a much-needed first step in addressing health disparities in the complicated US health care system.

China

China is one of the most populous countries in the world, with a population of 1.4 billion people. In China, CVD is the leading cause of death, accounting for 43% of deaths, including premature death.⁴⁵ In the past few decades, the country has seen a booming economy, bringing about considerable transitions in its demographics and epidemiology.⁴⁶ Urbanization and higher incomes have improved life expectancy significantly but, at the same time, put NCDs, particularly CAD, on the rise.⁴⁵

Nationwide community-based registry data have shown that SES correlated negatively with cardiovascular health, which applies to both the individual and regional levels.⁴⁷ Lower CVD prevalence was observed among individuals with higher annual incomes. CVD was more prevalent in rural compared with urban areas (8.4% vs 7.5%). The country’s unique health care system may play a role in how socioeconomic factors determine cardiovascular health. The primarily hospital-based health system has made primary care and the practice of preventive medicine challenging.⁴⁸ The traditional system of social health insurance provides coverage for mainly hospital care. Urban tertiary care centres are, in general, better funded and attract the most qualified health care providers.⁴⁹ The absence of distinction between prescribers and dispensers may prompt revenue-based rather than evidence-based treatment decisions.⁴⁹

Several SDOH factors in China may also influence the population’s risk for CVD. One study showed that, among Asian countries, China has one of the widest differentials between low and high educational attainment in terms of the risks for CVD and all-cause mortality, which was largest in China, Taiwan, and Thailand.¹⁴ Another important SDOH that China has to address is the integration of complementary/alternative medicine (CAM) and Western modern medicine in treating CVD, especially as there has been an increase in people’s acceptance of Chinese traditional medicine in the last 30 years.⁵⁰

To mitigate socioeconomic discrepancies in NCDs, the country is beginning to put forth multisectoral public health programs (eg, taxation and regulation of tobacco use and second-hand tobacco exposure) to target these modifiable factors.⁴⁸ The introduction of commercial health insurance and the opening of nongovernment health care facilities reflect a health care system evolving to adapt to this country’s rapidly shifting socioeconomic and epidemiologic landscape.

India

Accounting for nearly 1.43 billion people, India is now the most populous country in the world.⁵¹ India has seen a general increase in CVD since 1990, and CVD remains the leading cause of death and disability.^52,53 It is estimated that the prevalence of CVD among Indian people is 422 million and is responsible for 26.6% of all deaths among Asian Indians.⁵⁴

Studies on the role of socioeconomic factors in the burden of CVD in India have primarily focused on differences in urbanicity. It is estimated that the CAD prevalence of Indians living in urban areas may be nearly double (13.2%) that of Indians living in rural areas (7.4%).⁵⁵ The New Delhi Birth Cohort Study noted a rapid increase in various CVD risk factors among Indian people, aged 29 to 36 years, living in urban areas.⁵⁶ During the 7-year follow-up period, the prevalence of obesity increased from 9% to 21% in men and from 13% to 25% in women. Hypertension prevalence increased from 11% to 34% in men and 5% to 15% in women. Finally, prevalence of diabetes doubled among men (5% to 12%) and women (3.5% to 7%).⁵⁶

Recent work examining the role of socioeconomic determinants on CVD among Indian people has focused on a potential “epidemiologic transition” or the emergence of chronic diseases among LICs Earlier studies of CVD among Indians noted that CVD was higher among individuals with greater educational attainment than individuals with lower educational attainment. Similar trends were seen by income; wealthier individuals had a greater prevalence of CVD when compared with more impoverished individuals.⁵⁰ Current evidence, however, remains somewhat mixed.

Recently, the Prospective Urban Rural Epidemiology (PURE) study, which pooled and harmonized national-level CVD and survey data from 76 LMICs, found that individuals of higher educational attainment and income have more significant hypertension.⁵⁷ Compared with individuals with no formal schooling, increasing educational attainment was associated with a 19% to 25% increased risk of hypertension among individuals from Southeast Asia, including India. Furthermore, compared with individuals in the lowest wealth quintile, individuals in the highest wealth quintile had an up to 28% increased risk of hypertension. Using the Longitudinal Ageing Study in India, it was also found that increased income, education, and higher social caste among middle-aged and older adults were associated with a greater prevalence of CVD risk factors.⁵⁸

In contrast, other recent national and international studies have noted a shift in the association of socioeconomic factors with CVD that mirrors more HICs. A recent study using the PURE dataset found that low educational attainment accounted for 12.5% of the risk of mortality caused by CVD for all countries, regardless of level of development.⁵⁹ For LICs, specifically (including India, Bangladesh, and Pakistan), individuals with a primary school education or less had 2.25 times the risk of mortality caused by CVD than people who were educated in trade schools or had college educations. However, the association between increased wealth and lower CVD was unclear.⁶⁰ Thus, unlike previous work noting a positive correlation between educational attainment and CVD in India, recent studies have shown evidence of a potential epidemiologic transition.

In evaluating the role of community-level socioeconomic development, Jung et al.⁶¹ examined the role of community-level socioeconomic development among Indians using the Indian National Family Health Survey, the District-Level Household Survey, and the Indian Annual Health Survey. In India, greater education was associated with less diabetes, hypertension, and obesity. However, the association between wealth and CVD-related comorbidities was less evident. Regardless of the level of community development, greater wealth was not significantly associated with a lower burden of CVD-related comorbidities.

Although unhealthy weight (body mass index ≥ 25.0 kg/m²) increased nationally in India between 2015 and 2021, the greatest increase in unhealthy weight occurred among individuals with lower education and wealth.⁶² Indian individuals from rural areas also had greater unhealthy weight than people living in urban areas. Similar trends were seen for hypertension and diabetes, and compared with individuals with higher SES, individuals with low SES had increased hypertension and diabetes. Furthermore, individuals with high SES experienced a constant or decreasing burden of hypertension and diabetes.

In addition to examining traditional socioeconomic factors (eg, educational attainment and income), there have also been efforts to examine the role of caste classification on CVD. However, national studies are mixed. Recently, it was found that individuals in higher castes have a greater prevalence of CVD risk factors.⁵⁸ Individuals of lower castes continue to have a higher prevalence of hypertension, even with greater educational attainment.⁶³

Although the prevalence of CVD in India has continued to rise, the burden of CVD has shifted from Indians of higher SES to those of Indians with lower SES. Still, it may be complicated by other markers of multiple factors—such as income, education, and diet—as well as the state of the health care system and health-related policies, which all play important roles in the burden of CVD.⁶⁴

This phenomenon of CVD being a widespread disease is alarming, as it poses a great economic burden to affected families and, on a larger scale, constitutes one of the top threats to economic development. Moreover, in areas where public health systems are not robust, health care expenditures can trap poor households in cycles of debt and illness.⁶⁵

Southeast Asia Region

Like economically transitioning countries such as India, there is heterogeneity in the association of different socioeconomic factors with CVD and CVD-related comorbidities. For example, greater educational attainment was associated with up to 50% lower odds of hypertension among Chinese, Malay, and Indian people living in Singapore.⁶⁶ However, individuals living in wealthier and more educated districts of Indonesia had a greater prevalence of hypertension, diabetes, and obesity than those in more impoverished areas.⁶⁷ Despite the greater burden of these diseases within communities with higher SES, individuals with greater SES were more likely to have greater awareness, treatment, and control of these diseases.⁶⁸ Similar trends of greater SES associated with higher CVD-related burden were also seen in the Philippines⁶⁹ and Myanmar.⁷⁰ Overall, although the burden of CVD is increasing throughout Southeast Asia, the burden continues to affect individuals of lower SES.

These discrepancies are highlighted in the Southeast Asia region, as there is a high burden of noncommunicable illness in LICs and MICs related to CVD. Of the many diseases that result in CVD, RHD plays a significant role in the disease burden. It remains the largest cardiac cause of morbidity and mortality in children, adolescents, and young adults in Southeast Asia. Globally, the disease burden of RHD has been reduced because of improved living standards, including primary and secondary prevention techniques. However, barriers to the implementation of primary and secondary prevention allow for RHD to remain prominent in certain countries in this region. These barriers include limited access to primary care, lack of health care workers, the expense of microbiological diagnosis or echocardiography, poor community awareness, and lack of recognition of acute rheumatic fever (ARF) by local clinicians. Furthermore, complications of RHD include valvular disease that can lead to heart failure, which increases the risk of developing embolic strokes, atrial fibrillation, and endocarditis, and ultimately requires surgical intervention, which is very limited in LICs and MICs. Improvement of SDOH by improving education, reducing poverty burden, and improving access to health care would benefit these countries significantly and ultimately reduce disease burden.⁷¹

Middle East Region

The Middle East region refers to the diverse geopolitical region around the southern and eastern shores of the Mediterranean Sea.⁷² According to the World Bank 2022 classification, the region includes various countries ranging from LICs, such as Syria and Yemen, to HICs, such as Saudi Arabia and the Gulf region.⁷³ The region comprises populations with significant social, political, and religious differences. Moreover, it has substantial inequalities and gender gaps concerning access to care, daily habits, and work opportunities.⁷⁴ Health care systems in Middle Eastern countries with lower income are affected by complex economic and political problems such as weak governance, armed conflicts, displacements, poor service coverage index, scarcity of health care providers, and unavailability or unaffordability of essential medications.^75,76

With the dearth of data from LICs, high-quality research data are lacking to report the burden of CVD and its social determinants in the Middle East region. Moreover, available publications mainly focus on individual countries or ethnic groups. Generalizing the findings of these studies in this complex region is difficult because of the significant ethnic, cultural, and socioeconomic diversity among and within the countries.

CAD is the leading cause of death in the Middle East region. According to the Global Burden of Disease (GBD) 2015 study, CVD deaths accounted for 34% of the deaths in the Eastern Mediterranean region, including the Middle East region and additional countries in Asia and Northern Africa region.⁷⁷ The prevalence of ischemic heart disease in the region has increased by 41% over the past 3 decades. Despite this rising burden, the region’s public knowledge and awareness of CVD and risk factors are limited.⁷⁸

Hypertension and a cluster of all dietary factors are the leading risk factors for CVD in the Middle East region.^77,78 A population-based cross-sectional study from Northwest Iran, a LIC to MIC, explored the relationship between socioeconomic factors and the prevalence of CVD.^10,79 The study found that, compared with those with high economic status, people with low financial status were 38% more likely to have CVD. One potential explanation for this finding is the negative correlation between SES and the burden and control of cardiovascular risk factors. For instance, a population-based large cohort study from Iran found that individuals with low SES had a higher prevalence of hypertension and a higher risk of complications because of lower treatment and blood pressure control.⁸⁰ Similarly, a prospective population-based study from Saudi Arabia reported a higher prevalence of cardiovascular risk factors among individuals in rural areas than in urban areas.⁸¹

A recent report from the GBD study also evaluated the burden of stroke and its attributable risk factors in the Middle East region and North Africa region between 1990 and 2019.⁸² The study demonstrated that the major contributing risk factors for stroke in the Middle East and North Africa region were hypertension, obesity, and ambient particulate air pollution. The burden of stroke had a negative association with the countries’ sociodemographic index (a composite of sociodemographic factors) level. For instance, individuals in countries with low sociodemographic indexes generally experienced a higher risk of mortality and disability with stroke. The risk of stroke-associated mortality was highest in countries with ongoing conflicts, which can be explained by lower access to preventive measures and acute stroke care.

Epidemiologic reports demonstrated significant gender disparities in CVD burden and treatment in the region. Compared with men, women with CAD in the Middle East region have a higher prevalence of cardiovascular risk factors, are less likely to receive appropriate medical therapy or interventions and have worse clinical outcomes.^78,83 A population-based study from Turkey revealed a gender-specific relationship between socioeconomic factors and cardiovascular risk factors.⁸⁴ In this study, lower SES was associated with a higher burden of cardiovascular risk factors and a lower burden of smoking in women. Conversely, men with lower SES had a higher prevalence of smoking but a lower percentage of other risk factors.

Africa

Cardiovascular care access and quality in Africa face unique challenges. Only one-half of the hospitals in sub-Saharan Africa have reliable electricity, which threatens the safe storage of thrombolytic agents, including streptokinase, the least expensive treatment for ST-elevation myocardial infarction (STEMI).⁸⁵ Compared with other continents, an unfortunate reality worse in Africa is the prevalence of poor-quality medications, including cardiovascular drugs. In a study of 9 countries in West Africa, 16.3% of prescriptions were of low to very low quality.⁸⁶ Moreover, most countries in Africa suffer from a shortage of health care workers, with 1.55 physicians, nurses, or midwives to every 1000 persons, well below the WHO threshold of 4.45 per 1000.⁸⁷ Despite an increase in the number of medical schools, emigration from Africa or “brain drain” leads to a continued shortage in physicians.⁸⁸ The rate of pacemaker implantation rate in Africa is only 2.66 per million population,⁸⁹ which is 250-fold less than the United Kingdom.⁹⁰ Within Africa, there is considerable heterogeneity in the availability of cardiac services, with better coverage in North Africa compared with sub-Saharan Africa (except South Africa).⁹¹

Colonial policies can create health care disparities: an example is the British colonial “Southern policy” in Sudan.⁹² People in North Sudan are predominantly Muslim and racially different from people in South Sudan, who are predominantly not Muslims. The “Southern Policy” was aimed to “protect” the South from “exploitation” by the more HICs in the North. Traders and travellers from the North were not allowed entry into the South unless they acquired special permits. During the colonial era, north Sudan benefited from the colonial investment in education and industry, whereas the South was neglected. After colonialism, this disparity was a direct cause of a long war between the North and South, from 1956 to 2005, which ended with Sudan’s separation into 2 countries, Sudan in the North and South Sudan in the South. In 2019, Sudan’s life expectancy at birth was 65.3 years compared with 57.8 years in South Sudan.⁹³

Similar regional disparities because of colonialist policy are seen in Ghana and Nigeria, where the southern coastal regions had a larger share of development than the northern regions. Children in northern Nigeria⁹⁴ and northern Ghana⁹⁵ fare worse in growth and mortality compared with their counterparts in the southern regions of both countries.

Future Global Strategies to Mitigate the Risk of CVD

Table 2 is a summary of the findings from this review. As CVD continues to rise worldwide, we must comprehend the social and economic influences that contribute to the emergence of risk factors, which affect clinical decisions about who gets screened and treated. Individuals confronted with adverse social and environmental circumstances encounter various financial, cultural, and institutional obstacles that make these vulnerable populations more susceptible to increased risk of CVD.²⁰ More precisely, when socially disadvantaged communities are identified, preventive strategies can be customized and directed at an earlier stage, before individuals display the typical risk factors. This is especially important, considering most chronic conditions, including CVD, have long induction periods.

Table 2.

Summary of the findings from this review

Region	Category of income*	Higher risk of CVD	Important findings
Canada	High income	Indigeneity and immigrant status, disability	Efforts to prevent disease instead of treating disease are increasing, but most are lifestyle-based, a few are environmental based, and even fewer are structural or systems-based.19
United States	High-income	African American and Native American	Expansion of health insurance decreased CVD deaths; 2 factors that reduced disparities were increases in cardiologists and median household income.41
India	Lower middle income	Urban dwelling and caste system	There is an epidemiologic transition of the burden of CVD shifting from Indians of higher SES to those with lower SES.64
China	Upper middle income	Increasing obesity	Multisectoral public health programs (eg, taxation and regulation of tobacco use and second-hand tobacco exposure) are created to target modifiable risk factors.48
South Asia	Lower middle income	Higher SES	Greater SES is associated with CVD, but increasing in lower SES.67,69,70
Middle East/North Africa	Lower middle income	Low financial status, women	Prevalence of CAD in the region has increased by 41% over 30 years, surpassing the prevalence in the Western World. Women with CAD have a higher prevalence of CV risk factors, are less likely to receive appropriate medical therapy or interventions, and have worse clinical outcomes.77,78
Africa	Low-income	Low SES	Regional disparities exist because of the remnants of colonialist policy.92

CAD, coronary artery disease; CV, cardiovascular; CVD, cardiovascular disease; SES, socioeconomic status.

^*Average gross national income per capital for countries of that region; category of income was obtained from https://datahelpdesk.worldbank.org/knowledgebase/articles/906519-world-bank-country-and-lending-groups.

In September 2015, world leaders gathered at the UN Headquarters in New York and set 17 SDGs that created a framework that would lead to the short and long-term prosperity of people and the planet. Ensuring healthy lives and promoting well-being for all at all ages was the third SDG, and 13 targets were identified to achieve that goal, one of which is achieving universal health coverage (UHC).⁹⁶ It can improve cardiovascular outcomes by allowing early treatment and control of cardiovascular risk factors and protects from the financial risk of catastrophic out-of-pocket payments.⁹⁷

There is growing evidence that early life adversity (ELA) and adverse childhood experiences have been associated with a higher risk of CVD outcomes in adults, including stroke, CAD, obesity, and type 2 diabetes mellitus.⁹⁸ ELA includes several SDOH and has been acknowledged as a factor contributing to unfavourable cardiometabolic health.⁹⁹

In many LICs and MICs, there is restricted awareness of CVD caused by significant obstacles such as technical limitations, a shortage of skilled personnel, inadequate infrastructure, and financial constraints. These challenges pose significant barriers to the effective implementation of affordable prevention of CVD and control initiatives. A strategy to invest in the improvement of public health infrastructure would ultimately reduce the discrepancies of health inequities in these populations.

Improvements to implement change must be made on the national, community, and individual levels. These include structural changes such as improving access to good schools and recreation centres in low SES areas, as well as expanding government-funded health care programs for the general population, particularly for those who are most socially vulnerable. Efforts should be made to increase health literacy and behavioural counselling for lower salt intake and tobacco cessation.^100,101

Although it is widely recognized that incorporating screening and interventions related to SDOH into the clinical care of chronic diseases leads to substantial improvement in patient outcomes, existing guidelines predominantly do not encompass SDOH-informed approaches.¹⁰² There should be robust SDOH data collection at the local, state, and national levels to improve the reliability and generalizability of data, particularly for underserved populations. The American Heart Association has also proposed extending education about SDOH for cardiovascular health care providers at all levels, refining electronic health record (EHR) tools to include SDOH screening and referrals as part of clinical practice.¹⁰³

Furthermore, the creation of a comprehensive polysocial SDOH risk score aimed at predicting CVD and validation of such a score in various sociodemographic settings is vital to making informed choices and policy decisions. This score could serve as a screening tool for health care providers in real-time settings, such as clinics and hospitals, and enable the assessment of cumulative SDOH burden. Outlines for developing such a score are available and should be broadened to encompass a diverse range of SDOH risk factors.^104,105

Providing financial aid for nutritious foods represents another community-based intervention that has proved beneficial for individuals with low incomes. Subsidization of healthy food products has been proved to encourage better dietary choices and decrease obstacles to adopting a healthy diet in areas identified as food deserts.¹⁰⁶ Similarly, imposing taxes and regulating the aggressive advertisement of unhealthy foods reduces consumption.¹⁰⁶ The same principle applied to increasing prices of tobacco products, in addition to state programs providing nicotine cessation therapy and negative depiction of smoking in mass media, has been shown to reduce smoking prevalence significantly.¹⁰¹

Engaging in regular physical activity is linked to a reduced risk of CVD, whereas physical inactivity is recognized as an independent risk factor for poor outcomes.¹⁰⁷ Despite the widespread knowledge about the impact of physical activity on CVD prevention, less than one-half the adults in the United States met recommended activity levels in 2011.¹⁰⁸ This deficiency is particularly pronounced among individuals with low SES, possibly because of increased job-related demands or limited access to safe places for exercise.¹⁰⁹

Living in less desirable neighbourhoods and food deserts are also associated with lower odds of exercise, hypertensive disorders, and diabetes, which are linked to short- and long-term cardiovascular morbidity and mortality.¹¹⁰ Policy interventions should ensure access to healthy foods through markets while addressing geographic proximity and affordability. Attending to environmental factors such as safety (eg, street crime, violence) and infrastructure (eg, sidewalks, cycleways) is also crucial when implementing policy interventions to improve physical activity levels in low SES communities.

The lack of information and public awareness contributes to delayed diagnosis, later presentation, and therefore higher treatment costs for most patients. However, even in low-income settings, evidence has demonstrated that it is more cost effective to prevent and manage CVD risks than to treat it.¹¹¹ It is crucial to assess the disease burden and raise awareness within communities about the hazards of CVD. This intervention should encourage shifting the CVD burden primarily from tertiary care to a model centred more on primary care and reduction of risk factors.

The most economical measures include tobacco regulation, minimizing salt intake, and making affordable generic medications easily accessible to individuals at elevated risk of developing CVD.¹¹² When integrated into further reaching nation-level initiatives, these measures have the potential to prevent 13.8 million fatalities within a decade across 23 LICs and MICs and improve adherence to preventive measures.¹¹²

Ensuring consistent access to health care remains a persistent issue in LICs and MICs, especially in remote rural regions. When compared with high-income nations, individuals in LICs and MICs typically have minimal contact with primary care physicians who could perform CVD risk assessments.¹¹³ Nevertheless, ongoing endeavours aim to enhance direct health care services in LICs and MICs, with promising results seen in community health outreach programs that delegate responsibilities to local health care workers.¹¹⁴

Effective strategies should include public health education initiatives delivered through various outreach programs and media platforms emphasizing preventive measures, particularly dietary habits, smoking cessation, and promoting physical activity. For these initiatives to yield the desired results, they should be culturally relevant and involve input from various levels within the community.¹¹⁵ This should be supplemented with training health care personnel and implementing treatment protocols designed to decrease the prevalence of these issues, facilitate early detection, and deliver suitable care.¹¹¹ Alter et al.¹¹⁶ state that health equity may require a political, strategic, and organizational system redesign. However, there is a simple, feasible way to measure dynamic socioeconomic measures using the postal code. This simple tool may inform root causes, interventions, and health-system designs to improve health equity. The availability of postal codes in most “big-data” sets allows for tracking of a person’s socioeconomic measurement over time. Intercountry variations in cardiovascular outcomes have been discovered between low-income and high-income communities. Postal codes can be a phenotypic expression of a patient profile that reflect a multidimensional interplay among the person, the person’s age, the person’s risk for disease, and the community environment within which the person lives. The literature review by Alter et al.¹¹⁶ demonstrated that dynamic social phenotyping using postal codes has been underappreciated. However, it must be noted that there is considerable heterogeneity within postal code areas that should be acknowledged when informing public health interventions. Health policy decision makers must make efforts to direct scarce resources to sustainable and evidence-based interventions. Data collection and research should be encouraged to identify gaps in care, assess the productivity of interventions, and prioritize effective and financially feasible programs.

Conclusions

Globally, the SDOH are major contributors to the risk and deaths from CVD. The health care system of a country has a significant impact on the health of the population. Prevention and treatment of CVD in HICs have reduced deaths from CVD until 2019, before the COVID-19 pandemic. Addressing the underlying factors that impact SDOH can significantly affect CVD outcomes. Nationally, the provision of health care insurance affects CVD significantly.

Although different countries and regions of the world have their specific issues, such as racism, treatment of Indigenous populations, and health care access, people from all countries are affected by pandemics and environmental factors such as air pollution. Efforts by the WHO and the UN are underway to make health equity a priority for all nations.