Abstract 20405: Potential Value of an Aspirin-Dose Trial for Secondary Prevention of Coronary Artery Disease: Informing PCORI and Future Trial Design
Objective: Despite established benefits of aspirin (ASA) in reducing risk for MI, stroke, and fatal coronary events among persons with preexisting atherosclerotic cardiovascular disease, uncertainty exists on the optimal dosage. PCORI recently funded a pragmatic RCT (ADAPTABLE) to answer this question. PCORI sought to explore how value-of-information (VOI) methods might be used to inform RCT design and funding decisions, using the ADAPATABLE trial as an example.
Methods: We developed two independent models of cardiovascular events and mortality among target patients using a probabilistic minimal and a maximal lifetime model. Each model calculated the potential VOI for comparative effectiveness research comparing two daily doses of ASA (81mg vs 325mg). Each month, patients in the model were at risk for MI, stroke, major bleed, minor side effects, and death from other causes. Model parameters were based on literature reviews and data analyses. The minimal model expressed value in life years and carried out VOI calculations for a 3-year trial resembling ADAPTABLE. The maximal model carried out VOI calculations in terms of life years, quality adjusted life years, costs and net monetary benefits.
Results: The minimal model estimated the expected life years under 81 vs 325mg of ASA to be 14.86 (se = 0.10) and 14.72 (0.31) respectively, (difference of 0.14 [0.29] years). The probability 81mg was optimal was estimated at 67%. The maximal model also found evidence favoring 81mg (Table). The most frequent optimal dosing strategy differed based on the specific outcome to be maximized. Analyses from the minimal model suggest that the population VOI reaches an asymptote at a sample size of 10000 per arm with minimal additional gains in value beyond 5000 person per arm trial.
Conclusions: VOI analyses can help decisionmakers explore uncertainties and tradeoffs. VOI analyses such as these can help PCORI and other funders inform their future decisions to make large research investments.
Author Disclosures: G.D. Sanders: None. A. Basu: None. E. Myers: None. D. Meltzer: None.
- © 2016 by American Heart Association, Inc.