The world's healthiest countries aren't the richest, study finds
Wealth alone doesn't make a nation healthy, according to new collaborative research from the University of Surrey and its international partners, which ranks 38 OECD (Organization for Economic Co-operation and Development) countries on their progress toward global health goals.
The study, published in Annals of Operations Research, shows that some of the world's wealthiest nations, including the United States and Canada, lag behind smaller economies in achieving the UN's Sustainable Development Goal 3 (SDG 3) — ensuring healthy lives and promoting well-being for all. Meanwhile, countries such as Iceland, Japan and Norway lead the way, supported by robust health systems and equitable access to care.
Using a new model co-developed by Surrey researchers, the study assessed how efficiently each country converts health investments into outcomes such as life expectancy, disease prevention and health care access. The results highlight that nations with well-integrated public health systems and preventive care achieve better outcomes for every pound spent, compared to those relying heavily on private health care.
"Money isn't everything when it comes to national health. It's how effectively countries use their resources that matters. Nations that prioritize prevention, universal access and social equity tend to outperform richer economies that focus more on spending than on strategy," says Professor Ali Emrouznejad.
The team used a Joint Variable Selection Directional Distance Function model — an advanced data-driven method that measures how efficiently countries turn economic and health resources into well-being outcomes. This approach also incorporated the impact of climate-related risks, revealing that countries with strong environmental health policies tend to consistently achieve higher overall health scores.
The findings underscore the importance of building efficient, equitable health care systems that integrate climate resilience into their planning and delivery.
"Policymakers should prioritize prevention, sustainability and equitable access over simply increasing health budgets. Our model highlights which countries make the most of what they have, and which could learn from their approaches. It provides a practical roadmap for governments aiming to achieve sustainable, high-performing health systems without wasting resources," says Emrouznejad.
More information: Raha Imanirad et al, Assessing health and well-being (SDG 3) in OECD countries: a joint variable selection directional distance function approach, Annals of Operations Research (2025). DOI: 10.1007/s10479-025-06837-9
