Toe amputations are often naively viewed as an inconsequential surgical procedure with little functional impact. Instead, a toe amputation is often the inciting event in a cascade of progressive loss of function and quality of life. One in three people undergoing toe amputations due to chronic illness fail to heal the amputation in a timely manner, requiring additional amputation surgery(ies) and one in five die in the following year. Inadequate healing may be related to suboptimal management of comorbid conditions (e.g., diabetes, peripheral vascular disease, depression and/or PTSD). Veterans with limited social support may be further limited in their ability to self-manage their illness and engage in treatment to facilitate healing and prevent additional amputation. Veterans who undergo r epeated amputations lose functional life years as they are hospitalized, recover from surgery, are re-hospitalized and undergo additional surgeries. This 3-year study has three primary aims: 1) to characterize amputation trajectories and evaluate trends in subsequent amputation and death in the year after initial toe amputation overall, based on demographic characteristics, selected clinical factors (e.g., vascular status), and geographic location (e.g., Veterans Integrated Service Networks [VISN]), 2) to evaluate the associations between modifiable risk factors and 1-year risk of subsequent amputation or death while controlling for important risk factors that confound these associations, and 3) to acquire knowledge, attitudes, and behaviors related to secondary prevention using semi-structured interviews among patients who have undergone a toe amputation and providers who care for these patients to develop future interventions that improve outcomes in these patients. We will accomplish these goals by using the newly constructed VHA Amputee Registry/Repository, merged with relevant VA electronic medical record data, and in-depth interviews with providers and patients. Our proposed research ? a retrospective cohort study including all VHA patients (~16,000-19,000) with diabetes with a first ever toe amputation between FY 2005 and 2016 -- will be the largest study conducted to date, national in scope, and will supplement structured data with unstructured data to ascertain key information about not only the amputation but also other relevant patient characteristics.
For Aim 1, frequencies and percentages of the following clinical outcomes will be obtained: subsequent amputation within 1-, 6-, and 12-months; counts of subsequent amputations; the final level of amputation at 12 months; and death. After evaluating crude rates, identifying and inspecting outliers, we will formally test for trends across time by including year as a predictor variable in logistic regression models, considering the use of piece-wise regression to allow for multiple slopes (non-linear trends). Similar models will be constructed to test for variation across VISN. Key modifiable risk factors for Aim 2 include behavioral factors (e.g., smoking, alcohol misuse), revascularization procedure and type (none, endovascular, and open), and adequacy of treatment mental health conditions (e.g., depression and post-traumatic stress disorder).
For Aim 3, we will conduct in-depth interviews with providers and patients who have and have not undergone a subsequent amputation, to gain insight into patient and system-level barriers to successful healing, policies or other activities that could improve care for patients who undergo a toe amputation, and patient and provider perspectives on factors that they think would lead to improved patient outcomes. By conducting a detailed evaluation of temporal and geographic variation, identification of modifiable risk factors, and interviews with patients and providers, we will understand system-level and individual-level variation in outcomes. Our study will lay the groundwork to re-position the PAVE program to incorporate toe/partial foot amputations into what has been a successful policy and program in the VA for decades.
Toe amputations are often naively viewed as an inconsequential surgical procedure with little functional impact. Instead, a toe amputation is often the inciting event in a cascade of progressive loss of function and quality of life. One in three people undergoing toe amputations due to chronic illness fail to heal the amputation in a timely manner, requiring additional amputation surgery(ies) and 1 in 5 die in the following year. Our proposed research will provide crucial information to improve the VA?s Amputation Prevention Program (PAVE) and enhance our understanding of the outcomes of toe amputations; the longitudinal trajectory of, and the regional variation in outcomes; the factors that contribute to risk of subsequent amputation; and the knowledge, attitudes and understanding of factors that contribute to subsequent amputation risk. Our findings will result in a critical step towards helping this high priority patient population maintain their ability to walk, improve their quality of life, and prevent them from needing another amputation.
