Regional Variation: Only Moderately Interesting

Abstract

In most aspects of life in these United States, diversity is viewed as a strength that we champion. It seems that only in the medical field is regional diversity regarded with a suspicious attitude. The underlying assumption appears to be that regional variation in medical care and especially in procedure utilization is due solely or mostly to “substandard” practices. Yet the United States is a markedly diverse and heterogeneous country. This diversity includes a great many things, not the least of which is biological diversity, and ultimately this leads to differences in medical care and medical procedures. Article see p 15 In this issue of Circulation: Cardiovascular Quality and Outcomes , Goodney et al1 present a study of regional variation in both carotid artery stenting (CAS) and carotid endarterectomy (CEA) in the Medicare population for the years 1998 to 2007. Their data are derived from a 20% random sample of Medicare databases and had to be subjected to a special “coding strategy” because data before 2005 did not adequately capture CAS procedure codes. This highlights the fact that CAS is a “new” procedure. Administrative data sets have not yet accommodated it fully, and a standardized clinical data set has only recently been created.2 The results of the Goodney study show that the total of all carotid revascularizations for these years declined slightly. The fall-off that occurred in CEA was matched by a corresponding rise in CAS, suggesting that there may have been substitution occurring during these years, with CAS replacing CEA in at least some cases. What was also noticeable to these investigators was that regional variation increased along with the rising use of CAS, from only a small amount of variation in 1998 to a greater …