The Adherence eValuation After Ischemic Stroke Longitudinal (AVAIL) registry: design, rationale, and baseline patient characteristics

Background Approximately one third of the 780,000 people in the United States who have a stroke each year have recurrent events. Although efficacious secondary prevention measures are available, levels of adherence to these strategies in patients who have had stroke are largely unknown. Understanding medication-taking behavior in this population is an important step to optimizing the appropriate use of proven secondary preventive therapies and reducing the risk of recurrent stroke. Methods The Adherence eValuation After Ischemic Stroke Longitudinal (AVAIL) registry is a prospective study of adherence to stroke prevention medications from hospital discharge to 1 year in patients admitted with stroke or transient ischemic attack. The primary outcomes are medication usage as determined by patient interviews after 3 and 12 months. Potential patient-, provider-, and system-level barriers to persistence of medication use are also collected. Secondary outcomes include the rates of recurrent stroke or transient ischemic attack, vascular events, and rehospitalization and functional status as measured by the modified Rankin score. Results The AVAIL enrolled about 2,900 subjects from 106 hospitals from July 2006 through July 2008. The 12-month follow-up will be completed in August 2009. Conclusions The AVAIL registry will document the current state of adherence and persistence to stroke prevention medications among a nationwide sample of patients. These data will be used to design interventions to improve the quality of care post acute hospitalization and reduce the risks of future stroke and cardiovascular events.