Review and guidance for presenting cost-utility analysis with small QALY gains.

BACKGROUND: The quality-adjusted life-year (QALY) is a preferred measure of effectiveness in health economic evaluations. Challenges arise when QALY gains are small, such as an unstable estimate of the incremental cost-effectiveness ratio due to a small, uncertain denominator. METHODS: Health technology assessments (HTAs) published from 2016 to 2026 by a Canadian provincial HTA program (Ontario) were reviewed to examine the characteristics of cost-utility analyses (CUAs) that reported QALY gains ≤ 0.02 in their main analyses. Based on this evidence, preliminary guidance for presenting and interpreting CUAs with small QALY gains was developed. RESULTS: Twenty-six CUAs from 15 HTAs were included. Six HTAs evaluated testing technologies and 9 evaluated non-pharmaceutical treatments. When interpreting CUA findings, we recommend the following: 1) present both the direction and magnitude of QALY changes, 2) assess consistency between QALY gains and clinical conclusions, 3) justify reasons for small QALY gains, 4) address the impact of uncertainty in technology costs, 5) use a larger number of iterations in probabilistic analysis to minimize randomization error, and 6) estimate QALY gains at the population level for screening technologies. CONCLUSIONS: Our preliminary guidance elucidates CUA results with small QALY gains and promotes greater standardization in health economic evaluation reporting.