OBJECTIVES: We investigated the health economic implications of aspects of recent trials of omega-3 fatty acids for the prevention and treatment of atherosclerotic cardiovascular disease.

METHODS: In 2021, we conducted a health economic analysis mimicking the design of the Reduction of Cardiovascular Events with Icosapent Ethyl (IE) –Intervention Trial to test the cost-effectiveness (from the Australian public healthcare perspective) of IE in addition to statins (vs. statins alone) over a 20-year time horizon, assuming the initially reported 25% reduction in the risk of ASCVD. However, due to potentially deleterious effects of the placebo in this trial, more recent data suggests 25% may overestimate the benefits of IE, and while the true efficacy of IE remains unknown, plausible hazard ratios (HRs) range from 0.82-0.95. To explore the effects of this uncertainty, we repeated the economic analysis across a range of plausible HRs and calculated the incremental-cost-effectiveness ratio (ICER) at the original annual price of IE used in the economic analysis (AU$1637), and calculated the annual price at which IE would be cost-effective at a given HR.

RESULTS: ICERs increased exponentially with an increasing HR; the original ICER of AU$39,868 per QALY at a HR of 0.75 increased to AU$56,900 at a HR of 0.82, over the willingness-to-pay threshold of AU$50,000 per QALY, and under the worst-case scenario (HR of 0.95), the ICER was AU$178,204. The annual cost at which IE would meet the willingness-to-pay threshold decreased linearly as the HR increased, from AU$2,004 at a HR of 0.75 to AU$1,543 at 0.82 and AU$695 at 0.95.

CONCLUSIONS: Uncertainty in efficacy has serious implications for cost-effectiveness and acceptable pricing of therapeutics. Health economic analyses should be updated as new evidence becomes available, as even small changes in efficacy and costing can have major impacts on health economic outcomes.