The report is a product of the VA/HSR Evidence Synthesis Program.

Prognostic Tools and Interventions to Prevent and Treat Diabetic Foot Ulcers: A Review of Reviews

Patients with diabetes have significant comorbidities and complications, which predispose them to an increased risk of developing a diabetic foot ulcer (DFU) with resultant poor outcomes, including amputation. Among Veterans with diabetes in 2010, about 3,400 individuals underwent a lower extremity amputation. The development of a DFU and its resultant treatment also results in a significant decrease in patients’ quality of life due to a reduction in physical and social activities.

Responding to a request from VA’s National Clinical Orthotic and Prosthetic Program Office, VA’s Evidence Synthesis Program (ESP) Center in Minneapolis, MN conducted this review of reviews of prognostic tools that assess the risk of developing DFU or outcome of an existing DFU, and orthotic and pedorthic (designed to help foot problems) interventions to prevent and treat DFUs. Investigators searched the literature, including MEDLINE, Embase, and the Cochrane Database of Systematic Reviews from inception to July 2021 – and found 30 relevant systematic reviews.

Summary of Findings

The PODUS 2020 prediction tool has the most favorable prognostic accuracy and feasibility characteristics to predict the primary or recurrent development of diabetic foot ulcers at two years in adults with diabetes who are ulcer-free. There were no identified tools to predict DFU outcome (amputation or non-healing) in adults with an existing DFU over a specified time horizon. The comparative effectiveness of orthotics and pedorthic interventions for preventing and treating diabetic foot ulcers is uncertain due to significant methodological limitations in the primary literature and systematic reviews.

Additional findings show:

• Four tools performed well to predict the development of a primary or recurrent DFU or amputation in adults with no DFU. Of these, PODUS 2020 has the most favorable prognostic accuracy and feasibility characteristics to predict absolute rates of DFU development at two years. However, no data exist to inform how risks for DFU change over time and appropriate rescreening intervals for any tool.
• Limited evidence suggests that off-loading and therapeutic footwear may prevent the development of primary and recurrent DFU, though uncertainty remains regarding comparative effectiveness.
• While limitations exist in the primary literature and systematic reviews of accommodative insoles, Total Contact Casts (TCC) and available removable devices may improve DFU healing. However, intervention adherence was low, and research to identify adherence barriers and facilitators is needed.

Implications for VA

Although the overall results of the effectiveness of orthotics and pedorthics are likely to be applicable to

Veterans with diabetes, factors related to patient preference and adherence are important contributors to effectiveness of any therapeutic footwear. Thus, a better understanding of Veterans’ preferences and adherence based on factors such as age, comorbidities, DFU risk (including prior DFU), foot anatomy, ulcer characteristics, and financial co-pays may alter efficacy and outcomes.

Research Gaps/Future Research

Future research is needed to develop prediction tools, including risk classification models like PAVE, to predict absolute rates of developing a first DFU in Veterans at a specific time point (i.e., screening tool for primary prevention). Once developed, these models should be validated in Veterans prior to implementation in VA. Research should also address appropriate re-screening intervals, particularly for patients who are insensate or lack pulses, and the feasibility of accessing preventative podiatry care for patients thus identified (currently PAVE 2+ at VA). Importantly, additional research is needed to determine whether subsequent triage and treatment decisions based on prediction tool results lead to improved health outcomes. Thus, research is needed to evaluate the optimal prediction tool for DFU development in Veterans, and the net benefit of using this prediction tool and the subsequent referral strategies, so as to target screening and referral to individuals most likely to benefit. Research is also needed to develop and validate tools that predict the outcome of an existing DFU at a specified time horizon.

In addition, future research is needed to assess the comparative effectiveness of orthotic and pedorthic therapeutic footwear options across the wide range of adults with diabetes who have – or are at risk for DFU. Identifying a “gold standard” for effectiveness (e.g., total contact casting) would permit assessment of the comparative effects of different options. Observational studies are unlikely to adequately assess comparative effectiveness given selection and confounding factors between individuals receiving different interventions. Thus, large, long-term randomized controlled trials should be prioritized. Provision of the intervention, DFU, and outcome characteristics, in detail, will aid in comparisons, allowing for like products and interventions to be grouped appropriately. Moreover, future research is needed in understanding patient preferences for therapeutic footwear or other interventions by clinical and foot characteristics, as well as patient, caregiver, clinician, and health system barriers and facilitators to adherence.

Kaka A, Landsteiner A, Sowerby C, et al. Prognostic Tools and Interventions to Prevent and Treat Diabetic Foot Ulcers: A Review of Reviews. Washington, DC: Evidence Synthesis Program, Health Services Research and Development Service, Office of Research and Development, Department of Veterans Affairs. VA ESP Project #09-009; 2022.

To view the full report, go to vaww.hsrd.research.va.gov/publications/esp/diabetic-foot-ulcers.cfm (Intranet only, copy and paste the URL in yor browser if you have intranet access.)

ESP is currently soliciting review topics from the broader VA community. Nominations will be accepted electronically using the online Topic Submission Form. If your topic is selected for a synthesis, you will be contacted by an ESP Center to refine the questions and determine a timeline for the report.

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This report is a product of VA/HSR&D's Evidence Synthesis Program (ESP), which was established to provide timely and accurate synthesis of targeted healthcare topics of particular importance to VA managers and policymakers –; and to disseminate these reports throughout VA.

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