Studies have shown that people with diabetes are about 10 times more likely to undergo a lower extremity amputation (LEA) than those without the disease. About 90% of diabetics who undergo an LEA have a pre-existing foot ulcer. Researchers have made many discoveries about how wounds heal, but these innovations have not led to the development of many new products for treating diabetic foot ulcers. “Many existing therapies are difficult to use, and the overall rate of healing after care hasn’t changed substantially,” says David J. Margolis, MD, PhD.

Explaining Variability

Previous studies have shown that there are regional variations in the rate of LEA among people with diabetes. A 2011 study found a nearly four-fold variation within the United States, but the reasons for this are unclear. To explore the issue further, Dr. Margolis and colleagues examined whether behaviors relating to diabetic foot ulcer treatment could explain geographic variations in the prevalence of LEA. Published in Diabetes Care, the study merged data from the U.S. Census, Medicare Part A and B, and the Behavioral Risk Factor Surveillance System (BRFSS). The BRFSS monitors the state-level prevalence of behavioral risks in adults with diseases. Lower-Amputations-Callout According to the study, LEA varied in the U.S., and regions with higher rates of LEA tended to be clustered together. The mean and median incidence of LEA was 4.5 per 1,000 persons with diabetes, but varied from 2.4 to 7.9 LEA per 1,000 persons by health referral region. “Areas where BRFSS participants noted more diabetes-based education reported lower rates of LEA,” Dr. Margolis says. “Interestingly, areas that had higher rates of LEA had lower rates of colon cancer screening.” He adds that some of this variation may be explained by health behaviors from people living in certain regions of the U.S.

A Health Literacy Issue

Dr. Margolis says that low health literacy may partially explain findings from the study. He reported that other studies have shown that few patients understood why their prior treatment had failed, and about half had problems following their healthcare provider’s amputation prevention recommendations. “In addition,” he says, “many were surprised that LEA was associated with other diabetes-related comorbidities.” The findings highlight the need for future research to formally evaluate health literacy with respect to caring for diabetic foot ulcers. This is especially true for when treatment is initiated, says Dr. Margolis. “It’s possible that we can prevent LEAs with better patient education on and communication about the need for proper foot care and the importance of getting treatment.”

References

Margolis DJ, Hoffstad O, Weibe DJ. Lower-extremity amputation risk is associated with variation in behavioral risk factor surveillance system responses. Diabetes Care. 2014 May 30 [Epub ahead of print]. Available at: http://care.diabetesjournals.org/content/early/2014/05/21/dc14-0788.abstract.

Margolis DJ, Hoffstad O, Nafash J, et al. Location, location, location: geographic clustering of lower-extremity amputation among Medicare beneficiaries with diabetes. Diabetes Care. 2011 Sep 20 [Epub ahead of print]. Available at: http://care.diabetesjournals.org/content/early/2011/09/19/dc11-0807.abstract.

Margolis DJ, Jeffcoate WJ. Epidemiology of foot ulceration and amputation: can global variation be explained? Med Clin North Am. 2013;97:791-805.

Armstrong DG, Kanda VA, Lavery LA, Marston W, Mills JL Sr, Boulton AJ. Mind the gap: disparity between research funding and costs of care for diabetic foot ulcers. Diabetes Care. 2013;36:1815-1817.

Feinglass J, Shively VP, Martin GJ, et al. How “preventable” are lower extremity amputations? A qualitative study of patient perceptions of precipitating factors. Disabil Rehabil. 2012;34:2158-2165.

Rothman RL, DeWalt DA, Malone R, et al. Influence of patient literacy on the effectiveness of a primary care-based diabetes disease management program. JAMA. 2004;292:1711-1716.