Rebalancing health investment across the life course: a high-value age segments framework for aging societies.

Health systems in rapidly aging societies continue to direct a disproportionate share of expenditure toward reactive, late-life care, despite evidence that earlier and mid-life investment can generate substantial long-term population health returns. High-Value Age Segments (HVAS) are proposed as a life-course framework for prioritizing health investment according to differences in marginal returns across age groups. Three broad periods are identified: early life from the fetal stage to approximately age 25, mid-adulthood from ages 26 to 55, and later adulthood from age 56 onward. Early-life interventions are associated with durable gains in health and human development, mid-adulthood interventions with delayed chronic disease onset and preserved productivity, and later-life interventions with reduced morbidity and maintenance of functional capacity. Embedding HVAS within policy frameworks may support more efficient and sustainable allocation of health resources under demographic aging.