Ranking and clustering G20 healthcare systems: a framework for U.S. reform.

Objectives: To evaluate and compare healthcare system performance across G20 countries and Poland using multidimensional indicators of health outcomes, infrastructure, workforce capacity, and disease burden. The study examines structural patterns associated with high performance and implications for U. S. health system reform. Methods: We analysed 34 standardised indicators from WHO, OECD, and national databases. Z-score normalisation enabled cross-country comparability, and hierarchical cluster analysis using Ward's method validated performance groupings. Countries were classified into five tiers. Results: Healthcare performance varied substantially across countries. Higher GDP per capita (PPP) was associated with better outcomes, though outliers showed that financial resources alone are insufficient. Japan, South Korea, and Australia formed the highest-performing group, characterised by coherent financing, strong regulation, and preventive investment. The United States, despite the highest spending, underperformed relative to most high-income systems. Conclusion: Economic capacity facilitates but does not guarantee strong health system performance. The countries in the highest-performing group share several institutional characteristics, including regulated insurance markets, structured cost-sharing mechanisms, and strong primary care systems. The U.S. may benefit from adopting elements of regulated, solidarity-based multi-payer models observed in higher-performing countries.