Each year approximately 750,000 people experience a stroke. Of these, an estimated 10% have strokes that are attributable to carotid atherosclerosis. Over the past 2 decades there have been substantial changes in the diagnosis and treatment of carotid artery disease including the development of new and improved non-invasive and invasive diagnostic tests. However, the ability to answer clinical and policy questions related to the management of carotid artery disease has been limited.
In 2007, the Agency for Healthcare Research and Quality (AHRQ) provided research funding to Duke University, a member of the AHRQ DEcIDE (Developing Evidence to Inform Decisions about Effectiveness) Network to undertake a study with two main objectives: 1) to evaluate temporal trends and geographical variation in the use of diagnostic imaging for carotid artery disease; and 2) to examine geographic variation in and predictors of carotid treatments and treatments for carotid artery disease. Medicare claims - one of the richest, most comprehensive sources of publicly available health care information - were used to gather retrospective data for analysis.