Patients at risk for amputation have a better chance of keeping their limb if they reside in a region where vascular care is commonly provided, according to a recently published study.

“Regional differences in amputation rates have been ascribed, at least in part, to patient-level factors such as race and socioeconomic status,” the researchers wrote. “However, it remains unknown if, in vascular care, “more is better”; that is, if patients who live in regions where vascular care is more intense have a lower likelihood of undergoing amputation from critical limb ischemia. In this analysis, we sought to characterize, at the regional level, the relationship between the intensity of vascular care and the population-based amputation rate in patients with critical limb ischemia. By studying variations in intensity of vascular care, we hope to gain insight into the effectiveness of different levels of intensity of vascular care in preventing amputation.”

Regional risk of amputation

Researchers used the Medicare Physicians/Supplier file and the Medicare Denominator file from 2003 to 2009 to identify patients aged 66 years and older undergoing major leg amputation. They studied regional comparisons between intensity of vascular care and amputation rate, as well as analysis of patient characteristics, structural processes of care and their associations with an individual patient’s risks of undergoing amputation for peripheral arterial disease (PAD) without an attempt at revascularization. The relationship between amputation and intensity of vascular care was defined as the proportion of Medicare patients who underwent any vascular procedure in the year before amputation.

Overall, researchers found that amputation rates varied widely by region, from less than one to greater than 27 per 10,000 Medicare patients. In the regions with high amputation rates, patients were more commonly African American and diabetic. After adjusting for patient characteristics and socioeconomic status, patients in high-intensity vascular care regions were significantly less likely to undergo amputation without an antecedent attempt at revascularization, according to study results.

Regarding comorbidities, study results showed that 35% of patients undergoing major amputation had diabetes, 58% had congestive heart failure, 24% had coronary artery disease and 41% had chronic renal insufficiency.

“We found that in several regions of the United States, many patients did not undergo aggressive treatment for peripheral arterial disease — and many of these regions had very high rates of amputation,” Philip P. Goodney, MD, MS, of the Section of Vascular Surgery at Dartmouth-Hitchcock Medical Center in Lebanon, N.H., and the Dartmouth Institute for Health Policy and Clinical Practice in Hanover, N.H., told O&P Business News. “We were surprised at the differences in amputation risk, and the lack of vascular care obtained by many patients at the highest risk for losing their limb. For example, amputation rates were highest in rural areas in the South, yet in these regions patients did not commonly undergo attempts at revascularization.”

Preventing amputation

The results of this study highlight the importance of education on treatment options other than amputation in regions with high amputation rates, Goodney said. In an effort to find out how these regions would benefit from education, future research should focus on understanding the effect of variation in vascular care on amputation risk, and how multidisciplinary preventive care — such as podiatric visits, wound care, diabetic monitoring and pharmacotherapy — affects amputation risk in patients with critical limb ischemia.

“These results mean that vascular care needs to be better aligned with need in several of these regions. In talking with physicians who care for vascular patients in high-risk regions, there are many obstacles — access, poverty, distance, anatomic and cultural — that make it difficult to prevent amputation,” Goodney said. “Our future work will try to deconstruct some of these obstacles to effective vascular care, by studying which treatments can be successfully delivered, even among the most challenging populations.” — by Casey Murphy

Disclosure: The study received funding from the The National Heart, Lung, and Blood Institute and the Society for Vascular Surgery.