Understanding the Racial and Socioeconomic Disparities in Diabetes-Related Amputations

Abstract

The global, regional and national burden of diabetes mellitus (DM) has a profound impact on public health. In the United States, an estimated 29.1 million people are affected, with significant prevalence within ethnic and racial minority groups, and the disease is the 7th leading cause of death. Notably, underinsured, African American and low-income populations are disproportionality impacted by diabetes-related lower extremity amputations (LEA). This critical analysis reviewed the existing literature to understand the associations between race, socioeconomic status and access to diabetic services. In addition, the analysis examined the advantages and disadvantages of potential strategies for reducing racial disparities in diabetes-related limb amputations. The literature review included articles published between 2011-2021 utilizing keyword searches in PubMed, OVID, and Medline. This analysis included published articles in English and also included gray literature. Results found that although race/ethnicity and socioeconomic status disparities persist, insurance status plays a critical role in amputation rate disparities in the United States. Improving access to healthcare through insurance coverage expansion, as well as instituting substantial policy change to insurance methods,  paired with holistic interventions like proven successful self-care management programs show promise in reducing disparities in LEA.

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Background

More than one-third of the US population is projected to have diabetes, one of the fastest growing chronic diseases in the United States, by 2050. Type 2 diabetes, a condition in which the body cannot properly utilize insulin causing blood sugar levels to rise, can result from lifestyle and risk factors such as obesity, family history, high blood pressure, and low physical activity according to the National Institute of Diabetes and Digestive and Kidney Diseases. Having diabetes increases the risk of peripheral arterial disease (PAD), a circulatory condition that reduces blood flow to limbs, causing foot ulcers or sores that can result in a gangrenous infection and lead to limb amputation. Each year, 130,000 diabetes-related lower-extremity amputations (LEA) are performed, disproportionately impacting lower-income, African-American, and underinsured communities. This disparity is due in part to socioeconomic factors such as fundamental disinvestment in higher risk communities, historic racial inequities, geographic variability, as well as reduced access to and the underuse of recommended preventive care.

According to Healthy People 2030, a health disparity is defined as “a particular type of health difference that is closely linked with social, economic, and/or environmental disadvantage.” These differences adversely affect groups of people who have systematically experienced greater obstacles to health, discrimination, or exclusion based on their racial and ethnic group and other characteristics such as socioeconomic status or geographic location. Social determinants of health (SDOH) contribute to inequities in health, impacting quality of life and require more public health programming than solely promoting healthy choices. Examples of these determinants SDOH include, but are not limited to: safe housing and neighborhoods, access to safe water and nutritious foods, education, income, transportation, and literacy skills.

The prevailing health behavior paradigm often fails to take into account the importance that SDOH and their impact on management of chronic diseases like diabetes; these social and environmental determinants can predict poor health outcomes in vulnerable populations.

It is well documented that diabetes affects certain groups of people more than others in the United States due to a myriad of interwoven racial, ethnic, socioeconomic and geographic health disparities. The table below, adapted from the CDC’s 2020 National Diabetes Statistics Report, highlights the disproportionate percentage rates of diagnosed and undiagnosed diabetes between 2013 and 2016. Although people who identify as African-American, non-Hispanic make up only 13.4 percent on the United States population, according to the U.S. Census Bureau, the estimated crude prevalence of both diagnosed and undiagnosed diabetes for this minority group is 16.4 percent.

Risk factors for diabetes-related complications like amputation are complex. According to national data from the Centers for Medicare and Medicaid (CMS) from 2007 to 2016, African American patients with PAD and diabetes were two to three times more likely than Caucasian patients with the same diagnosis to have a limb amputation. The use of routine preventative measures, such as foot exams and bypass surgery to avoid or mitigate amputation, also varied by region and race. Although improvements in vascular treatment strategies have been associated with declining diabetes-related amputation rates, a study between 2002 and 2010 of 17,463 fee-for-service Medicare patients found that only one-third of patients were seen by a vascular specialist in the year before amputation. Socioeconomic factors and Medicaid/Medicare participation are significant contributors to increased risk of amputation among minorities, however no data within the last decade have determined the correlation between insurance status, low income, and race on amputation rate disparities. This is significant because much of the at-risk target diabetic population exist in economically disadvantaged regions with limited physician referral and multidisciplinary care management.

Limb salvage care, defined as limb-related admissions and procedures that occur during the 2 years prior to amputation, provide promise for at-risk diabetic patients. However, black patients are significantly less likely to have undergone arterial testing, revascularization procedures, limb-related hospital admissions, toe amputation, or wound debridement prior to amputation.  Diabetic patients with severe blockages in leg arteries can sometimes be treated with minimally invasive revascularization procedures to restore blood flow, yet angiograms-which act like an X-ray for blood vessels- are used less on black patients to access revascularization potential. Angiograms catch the buildup of fats and cholesterol before they narrow blood vessels and starve limbs and organs of oxygen-rich blood or assess how badly a blockage threatens a limb. Unchecked, this buildup can progress to non-healing sores, gangrene, that require amputation.  While racial bias may factor into diabetic amputation disparities, gaps exist in recent data on the role of insurance status, specialized care referrals and environmental factors, such as adequate health workforce and geographic proximity to hospital referral regions.

Disparities persist not only in the rate of amputations, but also in the severity of the surgeries, most often a consequence of delay in diagnosis and care. The adverse effects of race, insurance coverage, geographic location, lack of medical provider trust and compliance, and comorbidities increase the risk for lower extremity ischemia and amputation.  Other countries have been successful in reducing disparities in diabetes-related complications through increased access to care. For example, in Taiwan, despite some disparities between genders, age groups, and levels of urbanization, a population-based study did find an overall downward trend in the annual prevalence of LEA in people with type 2 diabetes from 2009 to 2013 after the implementation of universal health insurance coverage. These findings show promise that the removal of financial and insurance barriers could improve access to care, increase utilization of preventative care seeking, and reduce unnecessary amputations.

Despite an increase in targeted public health initiatives to reduce ethnic and racial disparities in diabetes care, geographic variability also exists within the United States and presents additional and unique challenges in decreasing diabetes-related complications. The “Diabetes Belt”, a geographically distinct cluster of 15 states spanning from Texas to West Virginia, has a diabetes prevalence of 11% or greater among the adult population. This Appalachian and Delta region is populated by 23.8% non-Hispanic African-Americans compared to 12.1% representation in the rest of the country and  has a higher prevalence of obesity and sedentary lifestyle, and shorter life expectancy at birth.16,17 Amputation rates in rural Southeast United States were seven times higher than any other part of the country.18 This population is also largely uninsured and underinsured.

Diabetic amputation places a physical, mental and financial burden on patients and society. Every year, each Medicare amputee beneficiary costs approximately $52,000. The disability can also cause loss of productivity at work, reduced income and quality of life, increased drug and healthcare cost expenditures and reduction in physical activity, an exacerbating risk factor of diabetes. Understanding the feasibility and limitations of procedures for reducing these disparities, such as mandatory preventative screenings for at-risk individuals and expansion of insurance coverage, is critical to determining what challenges to care exacerbate disparities in diabetes health outcomes.

Health inequities have been well documented decades, however the majority of previous studies evaluating disparities examined racial/ethnic disparities and socioeconomic factors independently. I seek to examine the intersection of race/ethnicity, socioeconomic status, insurance status and geographic location to evaluate the feasibility of comprehensive multi-layered policy recommendations. Evidence suggests that improving and standardizing access to healthcare with sustainable federal funding, instituting substantial policy change to insurance methods, bolstering primary care workforce in underserved US regions paired with proven successful self-care management programs combined will have greatest impact in high-risk communities.

Specific Aims

The first aim of this critical analysis is to understand the intersections and pathways between race, insurance status, geography and healthcare access on diabetes-related amputations. The second specific aim is to examine the advantages and disadvantages of potential strategies for reducing racial disparities in diabetes-related limb amputations, such as public health programming targeting at-risk communities, and the influence of insurance coverage or status. The third aim of this critical analysis and unique contribution to the literature will be policy recommendations to address this target population’s unique socio-economic and environmental factors that make positive diabetic healthcare outcomes harder to achieve. The overall goal of this analysis is to identify comprehensive solutions necessary for addressing this systemic and preventable health outcome.

To address these aims, the following research questions will be asked in this critical analysis:

1. What is the intersection of race, socioeconomic factors, geographic variability and healthcare access on diabetes care management and what impact does this intersection have on diabetes-related limb amputations?

2. Does expanding insurance coverage impact access to vascular services that could mitigate lower-extremity amputations?

3. What are current US policies impacting diabetes-related disparities and what policy recommendations will address these disparities in lower-extremity amputations?

To see complete critical analysis, visit this link.

In Fulfilment for the Masters of Public Health Degree

Milken Institute School of Public Health

The George Washington University