Demystifying the 1-3×GDP per capita cost-effectiveness threshold: lessons from empirical real-world estimates

Cost-effectiveness thresholds (CETs) are widely used to inform health technology assessment and resource allocation, yet many countries continue to rely on the heuristic 1-3×GDP per capita (GDPpc) rule originally proposed by WHO. Using a synthesis of international empirical studies, we compare GDP-based thresholds with CETs derived from real-world estimates of the marginal productivity of health expenditure. Across 10 countries spanning different income levels, empirically estimated CETs consistently fall below the upper bound of the 1-3×GDPpc rule and, in most cases, below GDPpc itself - particularly in middle-income settings. Applying inflated thresholds is, therefore, likely to generate net population health losses, as resources are displaced from more productive uses. Our findings highlight a persistent misalignment between global heuristics and country-specific opportunity costs. We argue that empirically grounded CETs provide a more coherent and ethically defensible basis for decision-making and should be preferred over mechanical GDPpc-based rules in economic evaluations, research, and editorial standards.