Project Background: Drugs such as anticoagulants and antiplatelets are commonly prescribed in combination to older veterans for secondary cardioprophylaxis. These agents are independently associated with risk of UGIE, the magnitude of which remains unknown. Furthermore, little is known regarding the preferences of elderly veterans for the risk-benefit of CAT strategies. To provide a basis for individualization of CAT strategies, we will quantify the UGIE risk of CAT and assess preferences of elderly veterans. We will then aggregate preferences at the cohort level to define patient archetypes. Project Objectives: First, we will quantify the UGIE risk of CAT strategies in a large cohort of elderly veterans. Then, we will elicit preferences for CAT strategies among older cardiovascular patients. We will assess the influence of specific medication attributes on patient choices, and define patient archetypes characterized by willingness to trade-off between cardioprotective benefit, associated UGIE risk and burden of self-management. Project Methods: To quantify the UGIE risk, we propose a retrospective cohort study among elderly veterans, using medical and pharmacy data from a merged VA-Medicare dataset from 01/01/03-09/30/06. A time-dependent analysis will assess UGIE risk associated with CAT strategies. In the second aim, ACA will define patient preferences for CAT strategies considering a range of trade-offs for UGIE (as quantified in the first specific aim), cardiovascular benefits and medication strategy attributes (i.e., complexity of administration, need for follow-up etc). Elderly multi-morbid cardiovascular patients will complete an interactive computer ACA to measure the relative influence of medication strategy on preferred choice for CAT. We will then aggregate individual preferences at the cohort level to delineate segments of respondents with similar preferences.
This study will inform healthcare providers and VA policymakers as to the real-life upper gastrointestinal event (UGIE) risk of combination antithrombotic therapy (CAT) prescribed to elderly veterans. These results, when used with the results of an adaptive conjoint analysis (ACA) survey, will help elderly veterans evaluate trade-offs associated with CAT strategies by explaining the risks and benefits of each option, helping them decide which is best for them based on what attributes are most important to them.