Abstract 13150: The Economic Implications of Non-adherence to Aspirin in Patients With Prior Primary Cardiovascular Events

Abstract

Introduction: Adherence to medications for secondary prevention of cardiovascular events has been shown to be poor in both general and high risk populations. Non-adherent patients are at higher risk of experiencing another CV event, leading to adverse clinical events and high costs. Few prior studies have explored the economic and consequences of non-adherence to aspirin in relation to cardiovascular health. Hypothesis: Improved adherence to aspirin will lead to lower healthcare costs and improved long-term survival rates. Methods: We developed a generalizable Markov model to estimate the cost-effectiveness of aspirin adherence. The rates of aspirin adherence, events and costs were gathered from published literature. We applied the model separately to a general (low-risk) population with no comorbidities and a high-risk population with type II diabetes. Outcomes of interest included fatal and nonfatal events, including secondary myocardial infarction (MI), stroke, other clinical CV events including PAD-related amputation as well as aspirin-related side effects (gastrointestinal bleeding). All costs were inflated to 2016 U.S. dollars to reflect the current cost of treatment. Results: The aspirin adherence rates for the low-risk and high-risk model were 85.8% and 76.5%, respectively. Both models demonstrated neutral average 5-year cost per member when comparing adherent to non-adherent population. The average 5-year survival was 0.26 years or 3.1 months longer amongst the adherent population in the low-risk model and 0.37 years or 4.4 months longer in the high-risk model. As a result, the ICER is $23 for low risk population while adherent strategy is dominant (lower cost, higher effectiveness) for high risk population. Conclusions: Adherence to aspirin therapy after experiencing a primary CV event is critical for patients’ well-being and can facilitate better health outcomes. This study demonstrates that aspirin adherence is essentially cost neutral and extends survival in low and high-risk patient populations, with a potentially cost saving outcome for patients with comorbid conditions such as diabetes.