5.1 The spatial-temporal variation of HPI in B&R countries is significantly correlated with their economic development history.
Our study shows that health poverty has improved in most B&R countries from 2008 to 2019, with only 8 out of 141 countries experiencing a slight increase in HPI. However, there are significant differences in the HPI for countries in different geographical subregions. Europe, as the end point of the LSR and the MSR, has the lowest HPI, with a mean value of 0.2122; while Africa has the highest level of HPI, with a mean value of 0.6131, and the HPI of the countries through which the MSR passes are lower than those of the countries within the African continent. As for Asia, the starting point of the Silk Road, most LSR countries have lower HPI than MSR countries. Although we find that the HPI varies from country to country depending on geographic location, the implicit reason behind this is the difference in social and economic development.
HPI shows a negative correlation with economic development, high-income countries have a better performance in HPI. In the rankings of the 2019 HPI (from low to high HPI), the top five countries are all high-income countries. In general, economic development can promote the establishment and improvement of the health system, including raising more health funds, providing more medical resources and improving the quality of its medical and health services to protect the right to health of the nation[127, 128]; moreover, the most direct reflection of economic development reduces the individuals’ economic risk of disease and improves the quality of the nation's health, and then strengthens the nation's health capacity[129–131]. At the same time, economic development can also lead to the progress of society, reduce social unrest, and improve the health of the whole society[103, 132]. Most of the countries through which the MSR passes (except Europe) have lower income levels than the countries through LSR[133]. Although the countries along the MSR have developed rapidly since the beginning of the 21st century (e.g., Malaysia and India in Southeast and South Asia [134, 135]), due to their colonial past[136, 137], they have risen to prominence in a shorter period of time than the countries along the LSR, and they have not accumulated enough in the areas of the health service system, infrastructure, and the construction of national health literacy[138–141], which has led to the economic development of these countries being at the same level as that of certain landlocked countries, but health poverty is more severe.
However, our study also found that not all high-income countries have higher HPI rankings than countries in other income groups. Among the top 20 countries in the HPI, Cuba is the only non-high-income group country with an HPI ranking of 11th, and it had the lowest HRPI throughout the study period. Previous studies have found Cuba to be among the highest ranked countries globally in all health indicators[142, 143]. This is largely due to its universal healthcare system, with the achievable primary healthcare focusing on prevention, priorities the right to health of the poor and vulnerable[144, 145]. Like Cuba, Georgia, as a low-income country, nevertheless has a higher HPI ranking than most countries in the upper-middle income group. Georgia also focuses on primary health care programs. It has carried out several reforms to focus on ensuring access to quality primary health care services, providing immunization, disease screening and maternal and child health measures[146, 147]. Furthermore, Georgia has very rich medical human resources. WHO data shows that in 2019, it has 75.03 doctors per 10,000 people, ranking first in Europe. it is not surprising that a nationwide primary health care system can be built[148, 149].
5.2 The most effective way to reduce HPI in low-income countries is to guarantee the basic right to health of their citizens.
Our study finds that compared to 2008, 16 countries experienced a decline in HPI of more than 0.1 in 2019, 13 of which are coastal countries and 3 of which are landlocked. Of these 16 countries, 8 are in the upper-middle income group and above, and 8 are lower-middle income countries (only 1 is a low-income country). Further dimensional decomposition shows that the most distinctive feature of the lower middle-income countries is the decline in their health rights poverty; and 75% of their HCPI also fell by more than 0.1. However, HRIPI declined by more than 0.1 in five of the eight upper-middle-income and higher groups, compared with only one of the lower-income countries. It is worth noting that in addition to the low-income group, the high-income group (Malta, United Arab Emirates), the upper-middle-income group (China), and the lower-middle-income group (Côte d'Ivoire) have countries that are all-encompassing types of declines in health poverty, and they provide a good model to follow for declines in the HRIPI for their respective income groups.
Although the HPI of most B&R countries is declining, the improvement in the low-income group, where health poverty is most severe, is not optimistic, with only one country experiencing a decline in HPI of more than 0.1. There may be three reasons for this: first, the lack of a basic health care system, safe drinking water and sanitation, and the inability of the state to ensure that nationals are able to enjoy the basic right to health[150–152]. Secondly, low health capacity, low education level, poor health literacy and poor quality of medical services brought about by low economic income have led to the nation's low capacity to acquire health and its inability to meet its own health needs[153, 154]. Thirdly, they are exposed to high health risks. On the one hand, they are exposed to high natural risks, and most low-income countries face a harsh living environment, with natural disasters and a lack of clean fuels for living[155–157]. On the other hand, there is poor social stability, terrorism, wars, religious and ethnic conflicts have led to countries being unable to maintain a stable state of development, which had a significant negative impact on the physical and mental health of their citizens[158–161]. While focusing on countries with declining HPIs, we also need to pay attention to countries with rising HPI, even though they are only eight countries. These countries have all seen very small increases in HPI, with Greece being the only country in the high-income group to see an increase in HPI, possibly because of a debt crisis in Greece after the 2008 financial crisis due to the government's high welfare policies, the later imposition of strict austerity and the continued recession in the country, which led to an increasing strain on the healthcare system and limited access to healthcare for its citizens[162, 163]. In addition, Syria and Libya have suffered great damage to their economic development, social order and health systems as a result of the wars that took place in 2011[164–167]. After the war, the HPI of them continued to rise, and although the post-war reconstruction has eased, it still has not returned to the pre-war level.
As can be seen from the HPI rankings of Cuba and Georgia and the rapid decline of HPI in countries in the lower-middle income group and below, for countries in the low-income group, the most effective way to rapidly reduce health poverty is to guarantee the right to health of nationals and build a sound primary health care system. It includes the provision of safe drinking water, the construction of basic personal sanitation, the popularization of basic health knowledge, the provision of regular vaccination, the prevention of various common chronic diseases, and the provision of basic medical and health services. But the improvement of health capacity depends on the state of development of the country, which cannot be achieved in a short period of time. Even China took about 40 years to reach its current level[168], so the protection of the right to health in low-income countries is of the utmost importance. Of course, the low-income countries alone cannot establish a perfect primary health care system, so the need for external forces to intervene. WHO in the last century began to advocate for low-income organizations in health development assistance, funding mainly from the United States and private charities[169]. Since 2016, China has also been providing health development assistance to low-income countries along the B&R through the HSR project, including the establishment of a cooperation platform for the prevention and control of acute infectious diseases, the provision of training for human resources in healthcare, assistance in funding for the construction of healthcare systems, and the provision of scarce medical resources[170–172]. During the COVID-19 period, when low-income countries generally lacked vaccines, China donated more than 400 million vaccines by 2021 to help them against COVID-19, and China has become the leading supplier of vaccines to low-income countries[173, 174].
However, health development assistance from a few countries alone is not enough to improve health poverty in low-income countries, and the efficiency of the use of aid funds is also affected by problems such as armed conflict, ethnic violence, inequality, debt, and corruption in the recipient countries[175, 176]. Therefore, what is needed is not just health development assistance from a single country or a few countries or international organizations, but a system of global universal health coverage with the participation of all countries in the world. We should establish a global system of universal health coverage in which all countries of the world participate, which include a vertical chain of health assistance from high- and upper-middle-income countries to low- and lower-middle-income countries, and a horizontal network of solidarity among countries within the same region. To eradicate health poverty, we need a multilevel, three-dimensional, and collaborative network involving all countries, rather than a single, politically motivated, and unequal system of dialogue.
5.3 The future eradication of health poverty in countries along the B&R will require differentiated strategies, especially in middle and high HPI countries.
The findings of the GTWR model show that most of the middle and high HPI countries are highly vulnerable to external factors and vary significantly across geographic space. However, the low HPI countries are less sensitive to changes in external factors and are more stable overall. This suggests that countries with different levels of HPI should have different targeted strategies to reduce HPI due to differences in economic development, social status, cultural differences, and geographical location.
Government health expenditures in Africa is among the lowest globally and increases in it can reduce the number of infant and child deaths and reduce deaths from infectious diseases in a short period of time, as well as provide a strong foundation for improvements in health outcomes such as life expectancy and all-cause mortality[177–179]. However, government health expenditures in Africa also face problems such as inefficiencies in spending, corruption, and the quality of the system, which seriously undermine the effectiveness of it[180, 181]. Therefore, government expenditures on health in African countries should be increased by increasing government investment and seeking more external development assistance for health to raise its order of magnitude. In addition, proper monitoring should be carried out to ensure the efficiency and fairness of its expenditures, while improving the governance capacity of State institutions and the corresponding institutional system.
The impact of urbanization rates varies the most across countries with different levels of HPI. Firstly, it has a greater effect on the eradication of health poverty in Asian middle- and high-HPI countries than that in African. It is mainly due to the fact that the middle- and high-HPI countries in the Asian region (especially in Southeast Asia) have experienced rapid economic growth dominated by labor-intensive industries in the past[182], which has led to an increase in the country's health capacity. In this case, urbanization is the next step in their development, which can rapidly integrate limited healthcare service resources and improve the efficiency of the healthcare delivery system[183, 184]. But in African countries, constrained by geography, cultural traditions and economic development patterns, urbanization has instead increased poverty and the burden of disease in Africa with extremely limited resources[185–187], leading to a weakening of the effect of urbanization on the eradication of health poverty in the context of limited healthcare resources. There is also a marked difference in the impact of urbanization rates on low HPI countries in Europe versus the Caribbean and South America, with a greater impact on the European region and a lesser impact on the Caribbean and South American regions. In Europe, it is mainly the higher population density (except in Northern Europe) and the greater availability of infrastructure, public services and healthcare resources in cities that make further urbanization effective in raising living standards[188]. South America, on the other hand, is already highly urbanized, with the majority of its population concentrated in coastal areas and an urbanization rate of over 80% in 2019 (higher than in Europe)[189]. However, urbanization has already had a negative impact on the health status of countries in South America due to a lack of governance capacity[190–192], so continued urbanization will have less impact on health poverty across the whole country.
In conclusion, for the high HPI countries in the African region, as the countries are more backward in terms of their level of development and their social development has not reached the stage of rapid urbanization. So, their urbanization needs to be approached with caution, and the groundwork for subsequent urbanization needs to be laid by improving health capacity as much as possible while safeguarding the basic right to health of the citizens. As for the middle and high HPI countries in South and Southeast Asia, the rapid economic growth in the past has made urbanization inevitable in the next stage of their social development, but the process of urbanization is also facing many problems, including environmental pollution, urban planning, outbreaks of infectious diseases, and traffic safety[193–195]. These countries need to learn from the experience of other mature countries, such as China, Japan, Korea and Singapore, in planning for coordination between health, education, work, life and the environment in the process of urbanization, and maximizing the use of limited resources to reduce health poverty.
It is worth noting that the GDP growth rate as of 2019 will exacerbate health poverty in the middle and high HPI countries in the East and Southeast Asia region while alleviating health poverty in the middle and high HPI countries in the Africa region. The East and Southeast Asia region has experienced rapid economic development since the 21st century[196–198], a period that has effectively improved the health capacity of these countries, with rising income levels, years of education, and life expectancy of nationals[199, 200], as well as further improvements in the accessibility and quality of healthcare services[66], and all-around hints of the health capacity of nationals. At the same time, based on improved health capacity, these countries have further improved their social security systems, such as various types of social insurance, labor security and human resources for medical care, thus effectively guaranteeing the right to health of nationals. However, rapid economic development in the short term has also brought about some negative impacts on the national health of these countries and aggravated their health risks[201, 202], such as the widening of the gap between the rich and the poor due to income inequality, the environmental pollution brought about by rapid industrialization, and the increase in the burden of various types of diseases[203–206]. Moreover, there are comprehensive social problems such as insufficient national governance capacity, the lack of a sound legal system in the field of health, the inefficiency of government expenditure on health, the irrational allocation of healthcare resources, and the lack of adequate medical care for vulnerable groups in urban areas[207–211].
Therefore, for the middle and high HPI countries in East and Southeast Asia, they need to refer to the experience of developed countries (such as Japan, South Korea, and Singapore). Focusing on the GDP growth rate, but also must coordinate the relationship between economic development, environment, health, and public services, and to do a good job in urban planning, pollution control, and resource allocation, and to improve the relevant laws and regulations and institutional systems of the country and improve the country's comprehensive governance capacity. Most of the countries in Africa are economically backward regions and are still at the primary stage of social development, where economic development is the most important task. An increase in the GDP growth rate can greatly enhance the economic income in African countries and thus improve their health capacity, to better protect the right to health of nationals and mitigate the health risks brought about by social instability, which will ultimately lead to a rapid decline in health poverty.