Presentation (CTI)

OBJECTIVES: Despite commitments from health technology assessment agencies to incorporate environmental impact into evaluations, consensus on methods is lacking and remain largely untested. Using four stylised severe asthma biologic profiles, this study aimed to demonstrate the potential of incorporating environmental impact into cost-utility analysis via an environmentally adjusted incremental cost-effectiveness ratio (ICER) and an incremental carbon footprint effectiveness ratio (ICFER), alongside a standard ICER, assessing whether environmental impact can enhance or change cost-effectiveness conclusions.
METHODS: A Markov model informed by UK asthma guidelines and life tables compared a theoretical market entrant and three stylised comparators with characteristics drawn from published evidence but not representing any specific product. Treatment profiles varied by administration frequency, setting, and annual manufacturing greenhouse gas (GHG) emissions. Emissions in carbon dioxide equivalents (CO₂e), from manufacturing, healthcare resource use and patient transport were sourced from literature to calculate the ICFER and were monetised using the UK Government Carbon Valuation trajectory to calculate the environmentally adjusted ICER.
RESULTS: Against the higher frequency, in-centre comparator, the standard ICER of £79,476 exceeded the £25,000-£35,000 threshold but the environmentally adjusted ICER of £33,330 fell within it, changing the cost-effectiveness conclusion. The ICFER ranged from -3,989 to -126,906 kg CO₂e/QALY across all stylised comparisons, with negative values indicating lower GHG emissions per QALY gained, providing a carbon price-independent complement to the environmentally adjusted ICER. At 60,000 patients eligible for biologic therapy in England, the GHG difference ranged from 37,800-246,000 tonnes CO₂e, equivalent to 18,900-123,000 London to New York return passenger flights.
CONCLUSIONS: Accounting for environmental impact in the economic evaluation can change cost-effectiveness conclusions when incremental cost-effectiveness ratios are close to willingness-to-pay thresholds and a sufficient difference in environmental impact exists between comparators. Population-level analysis enhances evaluation by quantifying the GHG consequences of treatment choice and their contribution towards net zero targets.