Improving Access to Primordial and Primary Stroke Prevention: Global Considerations.

Digital health can increase access to care necessary for primordial and primary stroke prevention. While access to providers may be limited in rural and underresourced areas and cost of implementation may be a barrier in low‐resource settings, digital health technologies can transcend geographic boundaries to mitigate barriers to necessary preventive health interventions. Digital interventions include mobile health applications, wearable devices, risk assessment tools, patient–provider communication through short message service texting, ecological momentary assessment to capture real‐time symptom and behavioral reporting, web‐based programs, telehealth, and remote patient monitoring. Artificial intelligence, another form of technology available to improve stroke risk screening, can leverage data, whether directly entered within a platform developed for risk screening or through primordial strategies using natural language processing, for example, that can identify individuals through algorithms who may be at risk on the basis of data included within electronic health records. Incorporating digital health tools as part of an overall approach to prevent and reduce stroke risk factors enables clinicians to provide early intervention before risk factor development and to decrease existing risk exposure to stroke. Such technology affords the ability to reach geographically remote patients through increasing education and stroke risk awareness; facilitates monitoring of health behaviors, such as physical activity, nutrition, medication adherence, and symptom tracking; and can be used to motivate patients to adopt health‐promoting behaviors. Moreover, digital health tools can promote increased access to care without the need for frequent clinic visits. 102 A 2021 systematic review by Feigin et al revealed that the use of smartphones, wearables, and other digital health technologies offer accessible mechanisms for tracking health behaviors and risk factors, enabling an additional resource for primordial intervention efforts. 91 These interventions have been used successfully in LMICs where lower literacy levels and limited resources can factor into intervention implementation and influence health outcomes. 103 Risk assessment tools, like the Stroke Riskometer application, offer providers a tool that is freely available and can quickly assess 5‐ and 10‐year risk of stroke using demographic, physical, and known contributing risk factor responses for individuals. 104 Awareness of stroke risk at these time points can be used to educate patients and encourage adoption of health behaviors. While this tool has been cross‐culturally validated in several regions, further expansion is needed in some global regions. 104 Given the high burden of stroke in Africa, for example, investigators piloted a mobile health tool to assess current stroke risk and provide culturally relevant, targeted educational resources for an Afrocentric population. 105 In a survey of Stroke Investigative Research and Educational Network stroke‐free participants (n=475), 84% were willing to know their risk of developing stroke, with ≈70% willing to use a mobile phone application to know and manage their individual risk. Overall, 66% preferred knowing their current risk versus those interested in knowing their 5‐year risk (7%), and only 2% interested in knowing their 10‐year risk of developing stroke. 106 Enabling real‐time reporting of symptoms and health behaviors through ecological momentary assessment embedded within mobile health interventions can minimize recall bias and increase accuracy of data collection compared with traditional retrospective reports of patient experiences. An advantage of ecological momentary assessment is the ability for patients to quickly report individual experiences, symptoms, and health behaviors as they occur each day, thus providing clinicians with up‐to‐date data on risk‐factor progression and adherence to recommendations. Ecological momentary assessment data, which are patient reported, can further be compared with physiological data obtained through wearables and other devices, such as Bluetooth‐enabled devices that transmit blood pressure and blood glucose recordings. 107 While future large‐scale research studies are needed, digital health offers a promising approach to primordial and primary prevention of stroke that is relatively affordable, accessible, and scalable.

Up to 60% of strokes may be prevented by implementation of primary preventive strategies at individual and population levels. 6 , 24 LMICs and underresourced populations in HICs contribute disproportionately to the global burden of stroke and disability. 73 Advances in evidence‐based clinical interventions for stroke prevention have led to increased life expectancy and a trend toward reduced morbidity, but these benefits have often failed to translate to low‐resource settings. 73 Current high‐risk and population strategies have had a mixed picture of successes and challenges. For an effective effort, there is a need for global and local synergies between health care providers, government and nongovernment agencies, industry, academic organizations, and individuals. An approach for primordial and primary stroke prevention that integrates population‐wide and targeted strategies toward individuals with any level of increased stroke risk with strategies aimed at prevention of other NCDs is most likely to be successful as many risk factors are shared between stroke and other NCDs. 6 Additional research on modifiable risks and additional support for adequate surveillance, workforce development, and policies aiming at preventing stroke and its risk factors are necessary for equity and access to quality care. 9 As many stroke risk factors are common to other major NCDs, such as ischemic heart disease, renal disease, and dementia, it is expected that the worldwide implementation of the solutions will not only halve the burden of stroke but also substantially reduce the disability and economic burden from other major NCDs. Additional research is needed to develop affordable, culturally appropriate, and population‐specific health technologies for effective primary stroke prevention, including digital decision‐making tools for clinicians and community health workers, and to establish the optimal balance between different primary stroke prevention strategies to maximize cost effectiveness and minimize inequalities. 6

Stroke costs globally almost US$900 billion per year, 6 and the cost of dementia in the United States, including that caused by stroke, was $1.3 trillion in 2019. 7 The global stroke cost is projected to increase to US$1.59 trillion by 2050, with an increase in stroke incidence in young and middle‐aged people. 3 According to the World Health Organization (WHO), noncommunicable diseases (NCDs) kill 41 million people each year, equivalent to 74% of all deaths globally. Cardiovascular diseases account for most NCD deaths, or 17.9 million people annually. 8 Each year, 17 million people die from an NCD before age 70; 86% of these premature deaths occur in LMICs. 8 Neurological disorders are a leading cause of NCD and the leading cause of DALYs. 9 One DALY represents the loss of the equivalent of 1 year of full health. 3 Stroke ranks among the 10 conditions, with the highest age‐standardized DALYs in 2021. 9 The NCD Countdown 2030 stated that the risk of dying from neurological conditions between birth and age 80 years increased for more than half of countries, making them the fastest‐growing cause of death among NCDs. 10 Ischemic stroke is the most common type of stroke (about 80% of all strokes), although the relative burden of hemorrhagic versus ischemic stroke varies among different populations, with a higher proportion of hemorrhagic stroke in LMICs. 11 Although risk factors for hemorrhagic and ischemic stroke are similar, their prevalence may differentially affect the incidence of stroke types or subtypes. For example, hypertension is a particularly important risk factor for hemorrhagic stroke but also contributes to atherosclerotic and small‐vessel disease, which can also lead to ischemic stroke. 11 Risk factors for stroke can be modifiable or nonmodifiable. 4 For example, age, sex, race, ethnicity, and some single‐gene disorders are nonmodifiable risk factors for both ischemic and hemorrhagic stroke. 11 Because women tend to live longer than men, they have a higher lifetime risk of stroke. 11 In addition, women have additional sex‐specific risk factors, including hypertension in pregnancy and other pregnancy‐related complications, endometriosis, hormonal contraception, and premature ovarian failure and early menopause. 4 Examples of modifiable risk factors include hypertension, diabetes, obesity, dyslipidemia, smoking, diet, atrial fibrillation, physical inactivity, and the co‐occurrence of vascular risk factors, especially in middle age. 4 , 11 Uncontrolled hypertension contributes to the greater proportion of hemorrhagic strokes seen in LMICs as compared with high‐income countries and an earlier age of stroke onset decimating the workforce and thereby stifling economic growth. 3 Additional factors that may contribute to the high burden of stroke in LMICs include lack of easily accessible and high‐quality health services for early risk factor detection and control and insufficient investment in prevention of NCDs due to the competing burden of infectious diseases. Other possible contributing factors include air pollution, psychosocial stress with low locus of control, 12 and unhealthy lifestyles (eg, poor diet, smoking, and alcohol consumption). 3 , 10 Potentially modifiable stroke risk factors and their population‐attributable risk (PAR) have been previously reviewed with some variations noted between different cohorts. 13 The PAR is the proportion of a disease's incidence in a population that is due to exposure to a risk factor. We summarize below the PAR of the most studied risk factors based on the evidence from a case–control study from 32 countries (INTERSTROKE [Importance of Conventional and Emerging Risk Factors of Stroke in Different Regions and Ethnic Groups of the World]; Table  1 ). 14 In all regions, hypertension was significantly associated with all stroke (PAR ranging from 38.8% in western Europe, North America, and Australia to 59.6% in Southeast Asia and 90.8% in Africa). 15 Dyslipidemia (apolipoprotein B/A1) was associated with ischemic stroke, with a PAR ranging from 24.8% in western Europe, North America, and Australia to 67.6% in Southeast Asia. Atrial fibrillation was associated with ischemic stroke, with a PAR ranging from 3.1% in South Asia to 17.1% in western Europe, North America, and Australia. For all stroke, the PAR associated with current smoking ranged from 4.5% in Africa to 18.0% in western Europe, North America, and Australia. 14 In Latin America and the Caribbean, up to 90% of the stroke risk could be reduced by targeting 2 modifiable factors: blood pressure and body mass index. 16 Air pollution, including household air pollution, especially in low‐income countries, is an additional emerging stroke risk factor but the corresponding PAR remains unclear. 16 Regional studies of risk factors are recommended periodically to determine risk factor burden and PARs for stroke. PAR for All Strokes Dysplipidemia Apolipoprotein B/A1 ratio tertile3 vs tertile 1 Cardiac sources include atrial fibrillation or flutter, previous myocardial infarction, rheumatic valve disease, or prosthetic heart valve. HbA1c indicates glycated hemoglobin; and PAR, population attributable risk.

M.O.O. is supported by the National Institutes of Health United States, Stroke Investigative Research and Educational Network (U54HG007479), SIBS Genomics (R01NS107900), SIBS‐Gen‐Gen (R01NS107900‐02S1), ARISES (R01NS115944‐01), H3Africa CVD Supplement (3U24HG009780‐03S5), CaNVAS (1R01NS114045‐01), SSACS (1R13NS115395‐01A1), TALENTS (D43TW012030), and GRASP (1UE5HL172183‐01). The funder had no role in the study design, data analysis, data interpretation, or manuscript writing.

A tripartite approach to primary stroke prevention, comprising behavioral, pharmacological, and structural interventions, superimposed on the socioecological model has been previously proposed to minimize fragmentation and improve effective implementation (Figure  2 ). 5 , 69 Behavioral interventions include raising awareness and implementation of nonpharmacological ways to decrease stroke risk at an individual level by improving habits. Pharmacological interventions include optimization of medications for stroke prevention. 69 Structural interventions: There are multiple interrelated structural factors that facilitate or hinder effective behavioral and pharmacological primary stroke prevention. 69 These structural factors include socioeconomic and cultural conditions, political environment and stability, government priorities or policies, and environmental context (eg, air pollution, unsafe and limited recreational spaces, nonwalkable communities). 70 Addressing these structural factors could improve the effectiveness of behavioral and pharmacological interventions for stroke prevention and reduce health disparities. 70 Behavioral interventions include raising awareness and implementation of nonpharmacological ways to decrease stroke risk at an individual level by improving habits. Pharmacological interventions include optimization of medications for stroke prevention. 69 Structural interventions: There are multiple interrelated structural factors that facilitate or hinder effective behavioral and pharmacological primary stroke prevention. 69 These structural factors include socioeconomic and cultural conditions, political environment and stability, government priorities or policies, and environmental context (eg, air pollution, unsafe and limited recreational spaces, nonwalkable communities). 70 Addressing these structural factors could improve the effectiveness of behavioral and pharmacological interventions for stroke prevention and reduce health disparities. 70 Reproduced from Bam et al 69 under the terms and conditions of the Creative Commons Attribution (CC‐BY) license ( https://creativecommons.org/licenses/by/4.0/ ). Barriers that hinder effective primary stroke prevention occur at national/environmental levels as well as provider and patient and community levels. The following are examples of the different types of barriers: Poor access to healthy foods or spaces for physical activity. Low availability and affordability of essential medicines. Lack of policies aiming to reduce the amounts of salt and sugar in processed foods. Lack of universal health coverage. 24 Inadequate prioritization of neurological disorders and brain health. 24 Limited funding and infrastructure for research and surveillance. 24 Insufficient policies to promote healthy dietary and lifestyle choices. Inadequate policies for NCD risk factor screening. 24 Political and social unrest, which may decrease the priority for primary stroke prevention or monitoring efforts on national, community, and individual levels. 71 Poor access to healthy foods or spaces for physical activity. Low availability and affordability of essential medicines. Lack of policies aiming to reduce the amounts of salt and sugar in processed foods. Lack of universal health coverage. 24 Inadequate prioritization of neurological disorders and brain health. 24 Limited funding and infrastructure for research and surveillance. 24 Insufficient policies to promote healthy dietary and lifestyle choices. Inadequate policies for NCD risk factor screening. 24 Political and social unrest, which may decrease the priority for primary stroke prevention or monitoring efforts on national, community, and individual levels. 71 Poor awareness of the importance of health surveillance and health advocacy and overwhelming health care personnel workload. 24 Cultural preferences for unhealthy diets and lifestyle factors. Lack of awareness regarding the importance of health surveillance and relationship to brain health or stroke risk. Low health literacy levels and poor health care–seeking behavior. Poor awareness of risk factors and opportunities for risk factor modification. 24 Mistrust of the health care system. 72 Cultural preferences for unhealthy diets and lifestyle factors. Lack of awareness regarding the importance of health surveillance and relationship to brain health or stroke risk. Low health literacy levels and poor health care–seeking behavior. Poor awareness of risk factors and opportunities for risk factor modification. 24 Mistrust of the health care system. 72 Other barriers amplified in low‐resource settings include poor baseline brain health and planning ability, poverty and inability to afford out‐of‐pocket payments for neurological or primary care services, and the lack of accessible transportation to health care facilities. These factors may result in delayed presentation or nonpresentation to health care facilities or poor treatment adherence. 73 In contrast to barriers, facilitators include: The use of affordable digital technology that helps in real‐time monitoring and feedback to the individuals, health care providers, national and local epidemiologists, and policymakers. Existing global or national frameworks for stroke prevention that can facilitate the creation and implementation of policy support mechanisms. These will need to be culturally tailored for wider adoption. 69 Structural interventions that include protocols to evaluate the safety, effectiveness of care, and resource use and to prevent adverse events. 74 Active advocacy engagement of public and private partners. 69 Accountability at the level of governments and policymakers at the regional, national, and international levels. 6 , 69 The use of affordable digital technology that helps in real‐time monitoring and feedback to the individuals, health care providers, national and local epidemiologists, and policymakers. Existing global or national frameworks for stroke prevention that can facilitate the creation and implementation of policy support mechanisms. These will need to be culturally tailored for wider adoption. 69 Structural interventions that include protocols to evaluate the safety, effectiveness of care, and resource use and to prevent adverse events. 74 Active advocacy engagement of public and private partners. 69 Accountability at the level of governments and policymakers at the regional, national, and international levels. 6 , 69 Implementation and accountability could be facilitated through continuous quality improvement and capacity building of an effective learning health system framework that allows adaptation based on the evidence in the setting in which efforts are implemented. 69 , 75

Pragmatic solutions to reduce the global burden of stroke lie in the establishment of regional and national plans. 6 The importance of international and national efforts and the collaboration between various sectors of health care, decision makers, government and nongovernment agencies, industry, communities, and individuals for effective reduction of stroke burden is essential in development of long‐lasting and effective solutions to reduce stroke burden. 6 , 35 In addition to preventive strategies toward medical risk factors, addressing social determinants of health is of crucial importance for effective primary stroke prevention. 6 , 76 A systematic review of stroke guidelines in LMICs revealed that none recommended surveillance and many lacked adaptation within the socioeconomic context. 77 Less than a quarter of these guidelines encompassed detailed implementation plans and socioeconomic considerations. These findings suggest that guidelines should be developed in conjunction with relevant partners with a full spectrum of translatable, context‐appropriate interventions. 77 The first pillar to reduce the global burden of stroke relies on surveillance, which includes research of the associated risk factors, alongside the quality and quantity of relevant health services at local, national, and global levels. For example, in rural southeastern Australia from 2004 to 2006, the National Preventative Health Strategy called for action to reduce obesity, alcohol consumption, and smoking. It recommended setting up a national prevention agency that will adopt a cyclical approach of “do, measure, report.” Measurements occurred through national risk‐factor surveys. 30 , 78 Surveillance should be linked to the development of meaningful objective measures of stroke risk factors that can be tracked across the life span. Each country should develop tailored surveillance approaches that incorporate local and national data collection strategies, disease registries, local pragmatic guidelines, and the ability to perform cost‐effectiveness analysis for various treatment options and to allocate budgets accordingly. 24 Effective policies should focus on monitoring, reporting, and analyzing the national stroke data, stroke risk factors, and other conditions with shared risk factors. The effectiveness of primary stroke prevention measures should be regularly assessed by monitoring stroke incidence, death, prevalence, and risk factors at the individual and population levels. Examples of such monitoring include the World Stroke Organization stroke survey, 77 the WHO health survey, 79 and the Global Burden of Disease Study. 6 , 80 The second pillar includes the implementation of stroke preventive strategies at the individual and population levels with priority given to population‐wide strategies. 6 Population‐wide strategies for primary stroke and cardiovascular disease prevention, such as nationwide measures to reduce exposure to smoking and vaping; reducing intake of sugary drinks, salt, and alcohol; and promoting adequate physical activity are recommended in several international guidelines, but their implementation remains slow and far from universal. 6 , 81 Population‐wide strategies should leverage health diplomacy and advocacy with innovative evidence‐based approaches, including digital and mobile health technologies, educational tools, social media, and task shifting and sharing. 24 , 82 For example, enabling community health workers to distribute medicines prescribed by clinicians may be particularly important in hard‐to‐reach regions where there is little access to medical professionals. 6 Health systems can be strengthened by workforce training and capacity building, as well as improving information systems and the mobilization and application of resources to ensure interventions are consumer‐centric and, ideally, codesigned. 24 Priorities should be to involve patients and advocacy groups in decision making to better define individual and community health needs and experiences. 83 Social media may be used for advocacy and education. Technological solutions, such as telemedicine, may also be used to bridge gaps in access and provide effective training for physicians, nurses, and other health workers. 24 As many lifestyle habits are set early in life, culturally appropriate education about healthy lifestyles should be incorporated into standard education curricula, with reinforcement across the life span and incorporate families. These preventive strategies should be complemented by adequate stroke education campaigns that consider cultural and subcultural differences, ethnicities, beliefs, geographical differences, and risk of stroke across the lifetime. 6 The implementation of population‐wide strategies also requires policy and legislative changes that may not be supported by major industries (eg, salt and sugar reduction in processed food and reduction of exposure to smoking and alcohol). 6 An example of national legislative actions to stop smoking were the proposals of the government of New Zealand aimed at creating a smoke‐free generation and moving the country closer to its goal of being smoke free by 2025. 84 The plans included the gradual increase of the legal smoking age. 84 , 85 Also under consideration was a significant reduction in the level of nicotine allowed in tobacco products, setting a minimum price for tobacco, and restricting the locations where tobacco and cigarettes can be sold. 84 New Zealand's restrictions were projected to bring economic gains in the long run, both by preventing health system costs and boosting earnings from people avoiding premature death and chronic disease. 85 However, these plans were reversed due to concerns about the development of black‐market tobacco products and the practicality of enforcing such a ban, as well as the loss in tax revenue from tobacco products sales. 85 , 86 Low income and unhealthy neighborhood food environments contribute to social inequalities in health. 6 , 87 Governments should be responsible for, and seek strategies to reduce the exposure of, their populations to unhealthy food and should facilitate the availability and affordability of nutritious foods. 6 Additional governmental and industry investments are needed to create affordable and widely accessible health services, improve access to affordable options for physical activity, and to reduce air pollution and socioeconomic inequalities. 6 However, despite a special 2011 United Nations declaration to have an NCD prevention plan in every country, most countries still do not have such a plan. 6 , 88 Other preventive strategies include improving access to primary care including women's health, with the goal of controlling or eliminating modifiable stroke risk factors. 24 Although the age‐standardized global hypertension prevalence did not change much from 1990 to 2019, improvements in detection, treatment, and control have varied substantially across countries. 89 Step‐by‐step action plans and free online courses on global salt reduction strategies for policymakers, advocates, and program managers were developed to implement scalable interventions focusing mainly on LMICs. 90 Examples of strategies targeting hypertension include screening and control programs by the WHO HEARTS package (healthy‐lifestyle counseling, evidence‐based treatment protocols, access to essential medicines and technology, risk‐based cardiovascular disease management, team‐based care, and systems for monitoring) and World Hypertension League, in collaboration with national governments and Resolve to Save Lives. 24 , 91 Examples of effective population‐wide strategies include smoking cessation campaigns in some countries 92 ; taxation of sugary drinks in several countries, including the United Kingdom, Ireland, France, Canada, South Africa, United Arab Emirates, Portugal, Mexico, and Sri Lanka 93 ; junk food taxes in Mexico and Hungary 94 ; successful alcohol reduction in Russia 95 ; and a successful air pollution campaign in China. 96 Future programs should also focus on tobacco and substance abuse prevention and cessation; maintenance and promotion of family and mental health and well‐being; nutritional interventions to incentivize access to and consumption of healthy food, including addressing food insecurities and taxation of unhealthy food; and provision of clean air and potable water, recreational facilities, and walkable towns and cities; along with measures to incentivize physical activity in schools, home, and work. 24 , 97 Actions to improve stroke prevention may be costly, and sustainable funding is an issue. A promising strategy to secure such funding is to reinvest revenues from taxation on unhealthy products (eg, tobacco, sugary drinks, alcohol, and salt in processed food) and the money saved from preventing strokes into health services and preventative strategies. 6 , 98 , 99 , 100 However, even high‐income countries (HICs) allocate <2% to 3%, on average, of their health spending to public health and prevention activities. 6 , 101 Although mainstream preventive strategies should be similar in HICs and LMICs, differences in the population‐attributable risks, lifetime risk of stroke, distribution of different risk factors, and availability of resources should be considered when setting goals and priorities. 6 , 15 For example, given the greater burden of smoking, air pollution, and hemorrhagic stroke in LMICs, 15 a strong emphasis on early detection and management of elevated blood pressure, reduction of air pollution, and antismoking campaigns should be a priority in LMICs. 6 In addition, in HICs, where smoking prevalence has reduced and the burden associated with ischemic stroke is noticeably higher than in LMICs, it seems reasonable to focus more heavily on the reduction of other behavioral risks, such as the reduction of sugar consumption and physical inactivity and on the identification and pharmacological or surgical management of medical conditions that lead to stroke. 6 Population‐wide and individual primary stroke and cardiovascular disease prevention strategies should be used together, with priority given to population‐wide strategies including behavioral risk factors. 6

In designing behavioral interventions using digital health, beginning with modifiable health behaviors offers the potential for the greater risk reduction. Lifestyle is a major contributor toward disease burden, and of the top 14 individually significant risk factors for stroke, 13 are modifiable with behavioral changes. 108 Digital interventions designed using motivational and behavior change theories based on personalized goals with feedback can help facilitate lifestyle changes to reduce disease risk associated with unhealthy behaviors. 109 Behavioral intervention also involves increasing awareness of stroke and contributory risk factors through patient education. The use of digital health for patient education reduces traditional challenges of time and location. 110 Providers struggle to educate patients sufficiently on health behaviors and disease risks, namely, due to time constraints. Using digital interventions, patients can have access to lay‐friendly educational information on health behaviors, risk factors, risk reduction strategies, and the importance of adopting a healthy lifestyle. This can be used as an adjunct to patient educational resources and training provided within the clinic setting as well as be a resource that patients can refer to as often as needed to better understand the information and to engage with the content at optimal times for them. Stroke awareness campaigns using digital platforms, such as web pages and social media channels, can empower individuals, families, and communities to make informed health decisions. 111 These tools can provide the public with credible health information, identify resources within their community, and offer tangible strategies for taking action. Community‐level environmental data accessible through websites and mobile applications can provide real‐time information on how and when to avoid environmental exposure risks, such as air pollution. While sustainability and ownership of such platforms remains unresolved along with an ongoing need for education on how to interpret and use the data among individuals and community members, these tools can be useful in addressing structural stroke risk factors, such as ambient particulate matter. 108 , 112 Digital health tools offer improved access to care, incorporate behavioral strategies to reduce disease risk and improve health, and increase community awareness on resources and personal risk mitigation efforts to improve individual and public health outcomes.

Social and economic factors, such as housing, education, and marketing of food items and lifestyle, are important determinants of health behaviors in the population. 26 Agency or the individuals' capacity to control their exposure to risk exists on a spectrum with those living in poverty or having lower education typically having fewer financial, cognitive, and social resources, including free time. 26 The level of agency required to respond to an intervention could be also considered on a spectrum, as could the degree to which an intervention is targeted at high‐risk groups or the population as a whole. 26 The 2019 European Union Strategic Framework for the Prevention of NCDs is a prevention framework that includes policy recommendations with supporting actions such as data systems and financial support. 27 This framework prioritizes the “creation of health‐enabling environments,” “addressing the commercial determinants of health,” and “tackling health inequalities,” which are all consistent with a definition of population‐level prevention framed around changing societal conditions and focusing on low‐agency interventions. 26 , 27 These population‐level prevention strategies tend to target changes in societal conditions, such as “structural or policy interventions that create healthier physical, economic, digital, social, and commercial environments.” 26 A definition for population‐level dementia risk reduction has been previously proposed to focus on the need to change societal conditions to minimize likelihood of developing modifiable risk factors without the need for high‐agency behavior change by individuals. 26 Owing to the similarities of many of the risk factors between dementia and stroke, a similar definition of population‐level strategy to decrease stroke risk is proposed. As such, a definition of the population‐level stroke risk reduction includes “measures applied to populations, groups, areas, jurisdictions, or institutions with the aim of changing the social, cultural, physical, commercial, economic, environmental, occupational, or legislative conditions to make them less conducive to the development or maintenance of the modifiable life course risk factors for stroke and more conducive to the development or maintenance of the modifiable life course protective factors for stroke.” 26 In comparison, high‐risk prevention strategies aim to identify and target interventions to those likely to have an increased incidence of a disease on the basis of the presence of modifiable risk factors known to be causal for the disease. The WHO recommends implementation of cost‐effective low‐agency, population‐level interventions. According to the WHO, such interventions include taxation, bans on advertising and sponsorship, reduced availability (eg, public smoking bans, reduced after‐hours alcohol sales), food reformulation, availability of low‐salt options, packaging that includes health warnings, and mass media campaigns for health education. 26 Additionally, with increasing scientific evidence that air pollution exposure increases stroke risk, decreasing air pollutant levels may further represent an opportunity for stroke reduction at the population level. 28 Multiple approaches to pollution reduction may be applied, including those targeting emissions as well as personal strategies, especially for high‐risk populations. Examples include decreasing individual exposure through monitoring local air forecast, activity modification to reduce exposure to pollutants, clean indoor air, and the use of personal protective equipment when needed. 28 Primordial and primary stroke prevention interventions, such as limitations on access to salt content in processed food and unhealthy foods, along with health policies to promote healthy environments (eg, smoking cessation campaigns, air pollution reduction, and public areas for physical activity) can be implemented by governments to reduce exposure to risk factors across the life span for the entire population, irrespective of the level of risk of stroke or cardiovascular disease. 3 To effectively reduce the stroke burden, in addition to strategies and policies at the population level, there is a need to develop strategies for decreasing the stroke risk in individuals at high risk, such as hypertension screening, home visits, and close follow‐up for hypertension in primary care settings. 29 The combination of both strategies tends to have the highest effect. For example, in rural southeastern Australia from 2004 to 2006, modeling different strategies of risk factor modification on the 5‐year probabilities of a cardiovascular event or stroke showed that among men, a population strategy could reduce cardiovascular events by 19.3% (193 per 1000 per 5 years), the high‐risk strategy by 12.6% (126 per 1000) and a combined strategy by 24.1% (241 per 1000); and among women, by 21.9% (219 per 1000), 19.0% (190 per 1000), and 28.7% (287 per 1000), respectively. 30

Reduction of the global burden of stroke, particularly in LMICs, by implementing primordial and primary stroke prevention is urgently required. Measures to facilitate this goal include (1) establishing a framework to monitor and assess the burden of stroke and its risk factors at a national level; (2) implementing integrated population‐level and individual‐level prevention strategies for people at any increased risk of cerebrovascular disease, with emphasis on early detection and control of hypertension and other risk factors; (3) building workforce capacity to monitor quality indicators for prevention services nationally, regionally, and globally; and (4) creating stroke advocacy and implementating ecosystems that include all relevant communities, organizations, and key partners. 3 Interventions should be designed to target both primordial and primary stroke prevention (Figure  1 ). Primordial prevention are interventions aimed at preventing the emergence of stroke risk factors. 31 Health disparities and inequities in the social determinants of health have emerged as challenges to optimal primordial stroke prevention across diverse populations. 24 , 31 The political, legal, ethical, cultural, social, and economic conditions of societies, in addition to the commercial determinants of health, all affect the success of preventing risks for stroke and cardiovascular disease. 31 Commercial determinants of health are described as “strategies and approaches to promote products and choices that are detrimental to health,” 32 such as unhealthy commodities including ultra‐processed food and drink, alcohol, and tobacco. 32 In 2021, the WHO report on the global tobacco epidemic also called for the regulation of electronic nicotine delivery systems, which often targets children and adolescents by using appealing flavors. 33 When children try electronic nicotine delivery systems, they are more than twice as likely to use conventional cigarettes in the future. 33 A total of 111 countries regulate electronic nicotine delivery systems in some way. 33 Implementing population‐based strategies that target the entire population over the life span and aim to reduce cardiovascular disease risk factors like promoting healthy diets and physical activity, and discouraging smoking from childhood to old age, are likely to have a bigger impact than only focusing on high‐risk individuals. 34 Mechanisms to implement these strategies include activities that prevent the emergence of risk factors via the establishment of environmental, economic, sociobehavioral, and cultural patterns of living via community interventions, policy changes, and educational campaigns. 35 Previous studies demonstrate a significant association between better cardiovascular health at younger ages and better health later in adulthood. 36 While some studies use Life's Simple 7 or 8 as their measure of cardiovascular health, others calculate their own health scores on the basis of known risk factors for developing cardiovascular disease. 4 , 36 Commonly examined outcomes include the development of hypertension, tobacco use, and markers of cardiovascular health, such as coronary artery calcification, carotid intima‐media thickness, retinal microvascular health, and pulse wave velocity. We summarize several examples of population level interventions that have the potential to improve primordial stroke prevention (Table  2 ). 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 Examples of Population‐Level Interventions for Primordial Stroke Prevention WHO FCTC 35 , 37 WHO MPOWER policy package: the package to help monitor and prevent the use of tobacco and help smokers to quit 35 FCTC 35 , 37 Reducing demand Protection from exposure to tobacco smoke Addressing tobacco dependence and cessation Education and public awareness Advertising, promotion, and sponsorship Price and tax measures Nonprice measures Regulation of tobacco contents Regulation of tobacco product disclosures Packaging and labeling of tobacco Reducing supply Limiting illicit trade Sales to and by minors Provision of economically viable alternative activities Protection of the environment Reducing demand Protection from exposure to tobacco smoke Addressing tobacco dependence and cessation Education and public awareness Advertising, promotion, and sponsorship Price and tax measures Nonprice measures Regulation of tobacco contents Regulation of tobacco product disclosures Packaging and labeling of tobacco Reducing supply Limiting illicit trade Sales to and by minors Provision of economically viable alternative activities Protection of the environment MPOWER policy package 33 , 35 Monitoring tobacco use and policies Protecting people from tobacco Offering help to quit Warning about the dangers of tobacco Enforcing bans on advertising, promotion, and sponsorship Raising taxes on tobacco Monitoring tobacco use and policies Protecting people from tobacco Offering help to quit Warning about the dangers of tobacco Enforcing bans on advertising, promotion, and sponsorship Raising taxes on tobacco According to WHO's 2017 report, comprehensive smoke‐free legislation is in place in 39 LMICs and 16 HICs, covering almost 20% of the world's population, but only 40% (n=22) of countries have high compliance 35 , 38 Implementation of smoke‐free legislation in parts of China between 2007 and 2016 was associated with a gradual annual decrease in the rates of ischemic stroke (6.3% [95%CI:‐8.9–‐3.6]) 39 As of 2020, >5.3 billion people (69% of the world's population) are covered by at least 1 MPOWER measure adopted at the highest level. 33 146 countries have at least 1 MPOWER measure in place, and 98 countries have at least 2 MPOWER policies in place at the highest level of achievement (covering about 4.4 billion people in 2020) 33 As of 2020, only 2 countries had adopted all MPOWER measures at best‐practice level (Brazil and Turkey) 33 Among the MPOWER policy measures, raising the cost of tobacco is the most effective 35 Healthy diet Promoting diets high in fruits, vegetables and whole grain Reducing salt in processed food Limiting sugar content in food and beverages The introduction of a tax on January 1, 2014, equivalent to an ≈10% increase in the sale price of sugar‐sweetened beverages, reduced sales by 6% in the following year in Mexico 40 but had only minimal effect on purchasing in Barbados 35 , 41 The health effects of reduced consumption are uncertain, but a simulation study in Mexico provided evidence that a 10% reduction in consumption of sugar‐sweetened beverages would result in 20 000 fewer strokes and myocardial infarctions and 19 000 fewer deaths per year 35 , 42 Development of healthy cities Active transport: Aspects of the built environment that encourage mixed‐use developments 35 Built environment that reduces exposure to pollution and second‐hand smoke, provides incentives to ensure access to fresh and healthy food 35 , 43 Designs that provide equitable access to education and health care 35 , 44 Reducing alcohol use WHO SAFER initiative (introduced in 2018): initiative and action package aimed to support global target of reducing harmful use of alcohol by 10% by 2025 46 Strengthen restrictions on alcohol availability Advance and enforce drunk driving countermeasures Facilitate access to screening, brief interventions, and treatment Enforce bans or comprehensive restrictions on alcohol advertising, sponsorship, and promotion Raise prices on alcohol through excise taxes and pricing policies FCTC indicates Framework Convention on Tobacco Control; HICs, high‐income countries; LMICs, low‐ and middle‐income countries; and WHO, World Health Organization. The relative contribution of risk factors to the stroke risk may vary across different countries and regions. 14 Household air pollution is an emerging risk factor, especially in low‐income countries. 16 The SIREN (Stroke Investigative Research and Educational Network) study, a multicenter, case–control study done at 15 sites in Nigeria and Ghana between 2014 and 2017, found that 98.2% (95% CI, 97.2–99.0) of adjusted PAR of stroke was associated with 11 potentially modifiable risk factors listed in descending order: hypertension; dyslipidemia; regular meat consumption; elevated waist‐to‐hip ratio; diabetes; low green, leafy vegetable consumption; stress; added table salt; cardiac disease; physical inactivity; and current cigarette smoking. 15 This suggests that addressing these risk factors may significantly decrease the stroke risk. However, the progress toward achieving Sustainable Development Goal 3 of reducing premature death from NCDs, including ischemic heart disease and stroke, by a third by 2030 relative to 2015 levels and to promote mental health and well‐being has been insufficient to meet the proposed target. 10 The WHO Package of Essential Noncommunicable disease interventions is a key component of the WHO's Global Action Plan for the prevention and control of NCDs. 48 The global experience with Package of Essential Noncommunicable disease interventions has been largely encouraging, with several countries successfully improving the management of NCDs in primary health care. 49 No country achieved the target by addressing a single disease. 10 Suggested interventions include tobacco and alcohol control, effective health system interventions for treatment of contributory risk factors and diseases, and primary and secondary cardiovascular disease prevention in high‐risk individuals. Examples of effective interventions to reduce population stroke risk include a mix of high‐risk and population‐based approaches and are summarized in Table  3 . 3 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 Examples of Primary Stroke Interventions The age‐standardized incidence rates decreased significantly for dementia by 5.4%, ischemic heart disease by 30.0%, and stroke by 35.3% Transcranial Doppler ultrasound is recommended as a screening strategy for primary stroke prevention in children with sickle cell disease with regular blood transfusion as a primary and secondary stroke prevention strategy. 50 Hydroxyurea (maximum tolerated dose) is used as the primary stroke prevention strategy in LMICs where transfusions may be too costly 50 In the United States, transcranial Doppler screening rates in a large real‐world cohort of 5247 children with sickle cell disease remains unsatisfactory across geographic regions (mean, 49.9%; range, 30.9–74.7%) 51 In a study of 196 children with sickle cell disease aged 2 to 16 y in Tanzania, treatment of patients with abnormal transcranial Dopplers with hydroxyurea resulted in no strokes in this cohort; 83% of those treated with hydroxyurea had transcranial Doppler reversion to normal velocities 52 Use of risk prediction models SCORE2 risk prediction algorithm: model to estimate 10‐year risk of cardiovascular disease in Europe 53 Afrocentric stroke risk 54 Genetic risk score 55 Using stroke risk calculators in primary care settings Use of risk prediction models may help with the targeting of individual‐level strategies for stroke prevention Diet Mediterranean diet 56 Daily consumption of green, leafy vegetables 57 Folic acid supplementation 58 , 59 Salt reduction 60 Population and individual‐level dietary interventions Use of seasonal, healthy, regional foods 35 Engagement with industry to reformulate foods and reduce the salt content of foods Consumer education, labeling schemes for packaged foods, introducing standards for the sodium content of foods for consumption in public institutions, and taxation 35 In the Northern Araki prefecture in Japan, a region with high intake of sodium and one of the highest rates of stroke worldwide, a public health campaign that lowered sodium intake also reduced blood pressure and substantially lowered stroke rates 61 In a 2014 meta‐analysis comparing various combinations of salt substitutes with sodium chloride, use of salt substitutes led to significant reductions in both systolic (−4.9 mm Hg [95% CI, –7.3 to −2.5]) and diastolic (−1.5 mm Hg, [95% CI, −2.7 to −0.3]) blood pressure 62 In the United Kingdom, collaboration with industry to achieve voluntary targets for sodium in >80 foods resulted in a 9.5% reduction in sodium intake between 2000 and 2008 63 Improving medication adherence with the polypill approach 64 The POLYIRAN44 trial 65 The International Polycap study 66 Use of mobile technology (mobile health application) Stroke Riskometer application 68 HICs indicates high‐income countries; LMICs, low‐ and middle‐income countries; and POLYIRAN44, Prevention of Cardiovascular Disease in Middle‐Aged and Elderly Iranians Using a Single PolyPill.

Brain health is crucial to the well‐being and function of every person and is key to both individual and social progress. 17 The WHO recognizes that brain health encompasses neural development, plasticity, functioning and recovery across the lifetime of an individual. 18 Primary prevention of stroke and dementia, including public and professional promotion of vascular brain health and healthy aging, as well as the promotion of mental health, are all essential elements of brain health. 17 The increasing number of multiple brain health initiatives, notably by the Centers for Disease Control and Prevention and the WHO, have fostered an understanding of brain health as an evolving concept whose continued progress requires collaboration between the public at large, community advocates, patients, scientists, and health practitioners to bring into effect meaningful change in research, advocacy, and public engagement. 17 Within this concept, the prevention of stroke is crucial to maintain brain health. 19 Stroke and dementia increase their mutual risks and share some of the same, mostly modifiable, risk and protective factors. 20 Clinically overt stroke is only the tip of the iceberg of vascular brain injury that includes silent infarcts, white matter hyperintensities, and microbleeds. 21 Up to one third of individuals with stroke develop dementia within 5 years. 22 In Ontario, Canada, the implementation of a stroke prevention strategy between 2002 and 2013 led to a 32.4% ( P =0.001) decrease in the age‐ and sex‐standardized stroke incidence with a parallel decrease in the dementia incidence of 7.4% ( P =0.009). 23 Even in the absence of overt stroke, overlapping pathologies including vascular mechanisms are common in dementia. 21 Synergistic action to improve brain health globally must not only leverage new scientific evidence and technological innovation but also build a broader coalition of multisectoral partners, including patients, health care service and product providers, policymakers, payers and funders of health care, implementation partners, and the general population. 24 For example, Norway ensured equitable income for its citizens and committed sufficient funds to universal health coverage while implementing a semicentralized and responsive health system with robust primary health care for brain health. This led to decrease the age‐standardized incidence rates for dementia by 5.4%, ischemic heart disease by 30.0%, and stroke by 35.3% from 1990 to 2019. 25

None.