Are quality-adjusted life years (QALYs) becoming more expensive? Evidence from economic evaluations of diabetic therapeutics

Empirical evidence regarding temporal trends in cost per quality-adjusted life year (QALY) gained remains limited. This study investigates the evolution of cost-effectiveness for diabetes mellitus treatments over time. We analyzed cost-effectiveness analyses of anti-diabetic pharmaceuticals extracted from the Tufts Medical Center Cost-Effectiveness Analysis Registry (CEAR). Incremental cost-effectiveness ratios (ICERs) were normalized by GDP per capita and categorized into four threshold-based groups. In addition, we examined temporal trends in incremental QALYs. Analyses stratified by Organisation for Economic Co-operation and Development (OECD) membership were also conducted. Among 239 eligible studies, the proportion of highly cost-effective interventions in OECD countries decreased from 62.50% (1999–2005) to 35.48% (2021–2023), while interventions exceeding 3хGDP per capita/QALY increased from 12.50% to 54.84%. This trend was less pronounced in non-OECD countries. Mean incremental QALYs remained stable (range: 0.19–0.47) across periods and between OECD and non-OECD countries, suggesting that rising costs rather than diminishing health benefits drive the declining cost-effectiveness. The cost-effectiveness of anti-diabetic medications has deteriorated substantially over time, particularly in OECD countries, despite stable therapeutic benefits. These findings highlight the need for dynamic approaches to cost-effectiveness thresholds and robust price negotiations to ensure sustainable access to innovative therapies.