"We found that areas of the country that had higher numbers of vascular surgeons had more bypass surgery performed and lower amputation rates," said principal investigator Vivian Ho, a health economist at Rice's Baker Institute for Public Policy and an associate professor of medicine at Baylor.

PAD is a condition in which fatty deposits build up on the inner linings of arteries, restricting the flow of blood to muscles and organs, especially the kidneys, stomach, arms, legs and feet. About 8 million to 12 million people are affected by PAD. The disease accounts for about half of all amputations among diabetics and is the major cause of amputation for nondiabetic patients.

Treatment often entails lifestyle changes and medication. Sometimes amputations can be avoided through bypass surgery in the lower extremities that improves blood circulation in the legs and feet; this procedure must be performed by vascular surgeons.

Amputation rates can vary as much as tenfold in different areas of the U.S., so Ho wanted to analyze whether the availability of vascular surgeons in a region affects revascularization and amputation rates for patients with PAD. Collaborating with the University of Alabama in Birmingham and Intermountain Health Care in Salt Lake City, Utah, Ho identified all patients with PAD in the Medicare claims data in 1994 and tracked their claims through 1999. She separated data on more than 143,200 patients who survived through 1999 by hospital referral region and merged it with information on the supply of local physicians and vascular surgeons.

Ho's statistical analysis of the data revealed that a .30 increase in the number of vascular sur
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Contact: B.J. Almond
balmond@rice.edu
713-348-6770
Rice University
8-Jul-2005