The research, led by Gonghua Wu, Huan Xu, and Xing Zhao of the West China School of Public Health at Sichuan University, together with collaborators at Sun Yat-sen University, Wuhan University, and West China Hospital, addresses a critical question in global cardiovascular health: whether decades of progress in hypertension detection and drug therapy have actually translated into equitable stroke prevention for entire populations, rather than for treated individuals alone.

Stroke remains one of the leading causes of death and disability worldwide, and high blood pressure is its single most important modifiable risk factor. Decades of randomized trials and individual participant data meta-analyses have established beyond doubt that lowering blood pressure with medication reduces stroke risk across a wide range of baseline blood pressure levels, in both primary and secondary prevention, and in men and women alike. What has been far less clear is how much of this protective effect has actually been “realized” at the population scale, where treatment coverage, adherence, and health system capacity vary enormously between countries and over time.

To quantify this, the team constructed a modelling framework that integrated country-, sex-, age-, and year-specific estimates of hypertension prevalence and treatment coverage with stroke incidence data for adults aged 30 to 79 years in each of 198 countries. The central metric of the analysis is the prevented fraction for the population, or PFP, defined as the proportion of strokes averted under the observed treatment patterns relative to a counterfactual scenario in which no one received antihypertensive treatment. In essence, the PFP answers the question: of all the strokes that would have occurred in a world without treatment, what fraction did existing blood pressure management actually prevent?

This counterfactual approach distinguishes the study from traditional population attributable fraction analyses, which typically estimate the burden caused by a risk factor rather than the burden already removed by an intervention. By anchoring the calculation in real-world treatment coverage drawn from population-representative surveys, including pooled analyses of 1,201 studies with 104 million participants and World Health Organization Global Health Observatory data, the researchers were able to track how the preventive yield of hypertension care evolved across three decades and how it differed by national income group as classified by the World Bank.

The results reveal a story of genuine progress shadowed by profound inequity. Between 1990 and 2019, the median PFP rose from 8.8 percent to 15.9 percent among women and from 5.1 percent to 11.8 percent among men. In practical terms, by the end of the study period, treatment patterns in a typical country were preventing roughly one in six strokes that would otherwise have occurred in women and nearly one in eight in men, compared with a no-treatment counterfactual. The researchers summarized these temporal trends using average annual percentage change and age-period-cohort analyses, statistical techniques that separate the effects of ageing, calendar time, and generational shifts in risk.

Low-income countries recorded the fastest annual increases in realized stroke prevention, a signal that many of the world’s poorest nations have been expanding hypertension treatment from a very low baseline. But the acceleration was not enough to close the gap. In 2019, the prevented fraction in low-income countries remained approximately half that of high-income countries, meaning that even after three decades of catch-up growth, the share of strokes averted by treatment in poorer nations still lagged dramatically behind the levels achieved in wealthier settings. The disparity reflects well-documented barriers in low- and middle-income countries, including limited availability and affordability of blood pressure lowering medicines, gaps in clinical practice guidelines, weaker hypertension care cascades from detection through control, and higher rates of medication nonadherence, all of which have been documented in large international cohorts and recent systematic reviews.

The sex differences in the analysis were consistent and persistent across the entire study period. Women showed higher prevented fractions than men in every year examined, a pattern the authors attribute to a combination of factors including higher rates of hypertension awareness and treatment-seeking among women, differences in healthcare contact, and possibly sex-specific prescription patterns, since systematic reviews have shown that women are sometimes less likely than men to receive cardiovascular medications even when clinically indicated. The finding underscores that although women benefit more from treatment at the population level, the gap itself points to under-treatment of men, who experience higher stroke incidence at middle age in many settings.

Equally striking were the age patterns. The prevented fraction remained low in older adults, the group that carries by far the highest absolute burden of stroke, and was similarly low, or even lower, in adults aged 30 to 34 years. In older populations, the low PFP may reflect therapeutic inertia, multimorbidity, polypharmacy, and the complexity of managing blood pressure in frail patients, factors associated with uncontrolled hypertension in geriatric cohorts. Among the youngest adults, low prevention likely reflects low treatment coverage, since young adults with elevated blood pressure are less likely to be screened, diagnosed, or prescribed medication, even though stroke in young adults carries enormous lifetime consequences in terms of disability, lost productivity, and inability to return to work.

The authors are careful to frame their findings as model-estimated rather than directly observed. The PFP calculation requires linking observed treatment coverage with assumed treatment effects derived from the trial literature, and the resulting estimates carry uncertainty intervals that reflect variability in the underlying data. Nevertheless, the methodology builds on established epidemiological techniques for quantifying deaths averted by existing risk factor prevalence, such as previous analyses of physical activity and mortality using the same prevented fraction framework, and incorporates bias-correction methods developed for population attributable fraction estimation in the presence of confounding.

The implications for global health policy are considerable. The study arrives amid alarming trends in stroke epidemiology: the Global Burden of Disease 2021 analysis found that stroke burden remains enormous and increasingly concentrated in low- and middle-income countries, where ageing populations and rising exposure to risk factors are outpacing gains in prevention. Meanwhile, hypertension prevalence among adults worldwide has remained stubbornly high, with roughly half of hypertensive adults unaware of their condition and the majority not achieving controlled blood pressure. If the realized prevention gap between rich and poor countries persists, the absolute number of preventable strokes in low-income settings will continue to grow.

The findings also add momentum to calls for population-wide strategies that go beyond individual clinical treatment. The World Health Organization’s global report on sodium reduction, along with meta-analyses showing that dietary sodium lowering reduces blood pressure in a dose-dependent manner, supports the case for structural interventions, including reformulation of packaged foods, front-of-pack labeling, and national salt reduction strategies, which evidence suggests can complement pharmaceutical approaches. Because much of the world’s dietary salt comes from manufactured foods, national policies targeting food industry practices may reach populations that clinical care cannot.

For the researchers behind the new analysis, the takeaway is that antihypertensive treatment has corresponded to substantial but uneven model-estimated stroke prevention worldwide. The three-decade trend is genuinely encouraging: millions of strokes have likely been averted, and the trajectory of improvement has been steepest where the need is greatest. But the half-fold gap between low- and high-income countries, the persistent disadvantage among men, and the low prevention achieved in both the oldest and the youngest adults together chart a clear agenda. Closing these gaps, the study suggests, will require not merely more antihypertensive drugs, but stronger health systems that can find, treat, and retain the patients who currently fall through the cracks, from the 30-year-old who never gets screened to the 75-year-old whose blood pressure remains uncontrolled despite a prescription.

The study was funded by the National Natural Science Foundation of China and the Postdoctoral Fellowship Program of the China Postdoctoral Science Foundation. The authors report no competing interests.

The study meticulously tracked cause-specific mortality, drawing on diverse and highly variable datasets from multiple regions, some with limited death registration completeness. Despite these challenges, the researchers established benchmarks for national performance by comparing each country’s recent trends not only to their historical data but also to regional peers. These comparative assessments reveal stark disparities: some nations continue to achieve substantial health gains, whereas others face stagnation or even reversal, highlighting the uneven trajectory of global health progress.

Central to the decline in chronic disease mortality is the impressive reduction in cardiovascular deaths, encompassing heart attacks and strokes. These improvements have been powered by widespread adoption of evidence-based interventions, including tobacco control policies, improved management of hypertension and diabetes, and enhanced acute care. However, offsetting these gains are rising mortality rates from neuropsychiatric disorders such as dementia and alcohol use disorder, alongside increases in cancers like those of the pancreas and liver. These opposing trends reflect complex epidemiological transitions and create formidable public health challenges.

A striking feature of the research is the divergent performance among high-income industrialized countries. East Asian nations, particularly South Korea and Singapore, demonstrated some of the greatest reductions in chronic disease mortality, showcasing successful integration of prevention, early detection, and treatment programs. South Korea, for instance, achieved the lowest mortality risk globally for females and ranked highly for males, with sustained declines across age groups and disease types. Conversely, the United States and Germany lagged substantially, with the U.S. showing the smallest mortality decline and concerning stagnation especially among younger adults. These disparities underscore differences in healthcare access, policy implementation, and socioeconomic factors.

The situation in Central and Eastern Europe contrasts with Western trends, with countries like Moldova and Russia registering notable mortality reductions primarily driven by declining cardiovascular deaths and effective alcohol control initiatives. These findings suggest that targeted public health policies can yield rapid dividends, even in regions historically burdened by high chronic disease mortality. However, vigilance is warranted, as variability in data quality and regional socio-economic dynamics may influence these patterns.

In Latin America and the Caribbean, the report reveals a complex mosaic. Chile stands out as a regional exemplar, achieving accelerated reductions in mortality from stroke, respiratory diseases, and diabetes, thus lowering chronic disease risk to levels comparable with advanced economies. In contrast, other countries including Jamaica and Antigua and Barbuda witnessed either deceleration or reversal in mortality declines, with deterioration largely linked to cardiovascular and renal diseases. Such heterogeneity speaks to divergent health system performance and varying degrees of policy enactment across the region.

India and China, home to a substantial proportion of the global population, present contrasting narratives. In India, the probability of premature chronic disease death has actually increased, with women facing a disproportionately higher risk. This uptrend is reinforced by rising incidence of heart disease and diabetes, emphasizing the urgent need for scalable interventions. China, meanwhile, continues to reduce chronic disease mortality robustly, mirroring progress achieved by neighboring East Asian nations. Notably, China recorded significant declines in chronic obstructive pulmonary disease deaths, an achievement attributed to improved air quality controls and rigorous tobacco policies.

A key revelation from the study is the widespread slowdown in progress. Approximately 60% of countries registered slower declines or outright reversals in chronic disease mortality compared to the early 2000s. This phenomenon is apparent across nearly all high-income nations, where initial rapid declines in the millennium’s first decades have plateaued. Factors implicated in this deceleration include plateauing coverage of preventive medications, stagnation in cancer screening expansion, and systemic gaps in equitable healthcare access, particularly for working-age adults who have shown alarming increases in mortality in some countries.

Stratification of mortality trends by age reveals that reductions in deaths among both working-age (under 65) and older adults (65-80) critically shape national performance. Countries like Finland and Norway, despite slower declines in older adults, balanced this with accelerated progress among younger cohorts, thereby limiting overall stagnation. Conversely, countries such as the USA exhibited troubling patterns of worsening mortality in younger populations, compounding challenges and driving poor aggregate outcomes.

Methodologically, the research navigated substantial data limitations, notably the incompleteness and variability of death registration systems, especially in low-income countries and Pacific Island nations. These data constraints necessitate cautious interpretation of trends, particularly in regions with scarce or low-quality mortality data. Additionally, year-on-year fluctuations in mortality statistics, exacerbated in countries with smaller populations, could influence short-term perceptions of progress or decline.

The study’s implications are profound. The initial global successes derived from aggressive tobacco control, early detection via screening, and broad deployment of preventative medications risk being undermined as momentum falters. To rejuvenate progress, the authors advocate for renewed investments in health services that target both prevention and management of chronic diseases, emphasizing evidence-based policy interventions proven effective across diverse socioeconomic contexts. Moreover, addressing social determinants of health and ensuring equitable access remain paramount.

Looking ahead, the report’s findings come at a critical juncture as world leaders convene at the United Nations General Assembly and the forthcoming Fourth High Level Meeting on Non-Communicable Diseases. This gathering aims to galvanize international cooperation and accelerate policy implementation in light of the study’s sobering revelations. The urgency expressed by global health experts underscores that chronic disease mortality, while declining overall, demands sustained and innovative strategies to prevent resurgence and ensure healthy longevity worldwide.

Imperial College London’s research team, led by Professor Majid Ezzati and supported by the UK Medical Research Council and National Institute for Health and Care Research, among others, underscores a complex interplay of successes and setbacks across the globe. This comprehensive data-driven analysis not only benchmarks country-level performance but also serves as a clarion call for reinvigorated global public health efforts to sustain and amplify gains against chronic disease mortality.

Subject of Research: Global trends and country-level analyses in chronic disease mortality reduction from 2010 to 2019.

Article Title: Benchmarking progress in non-communicable diseases: a global analysis of cause-specific mortality from 2001 to 2019.

News Publication Date: Embargo held until 10th September 2025.

Web References: Links to embargoed and post-embargo scientific publication hosted on The Lancet’s platform.

References: Bennett, J., O’Driscoll, O., Stevens, G., et al. “Benchmarking progress in non-communicable diseases: a global analysis of cause-specific mortality from 2001 to 2019”. The Lancet. DOI: 10.1016/S0140-6736(25)01388-1.

Keywords: Chronic diseases, non-communicable diseases, mortality trends, cardiovascular disease, cancer, global health, epidemiology, public health policy, health disparities, screening programs, preventative medicine, international health.