Risk stratification systems for diabetic foot ulcers: a systematic review

External validation of the DIAFORA system to predict lower-extremity amputations in a prospective Danish cohort

AIM

A diabetes-related foot ulcer (DFU) is a major risk factor for lower-extremity amputation (LEA). To help clinicians predict the risk of LEA in people with DFU, the Diabetic Foot Risk Assessment (DIAFORA) system was developed but has never been externally validated.

METHODS

In this study, 317 people presenting with a new DFU were included. At baseline, participants were grouped into three groups based on their DIAFORA score: low-risk (<15), medium-risk (15-25), and high-risk (>25). Participants were followed until healing, LEA, death, or at least 3 months. Discriminative accuracy was evaluated using sensitivity, specificity, likelihood ratios (LRs) and the area under the curve (AUC).

RESULTS

All 317 participants completed at least 3 months of follow-up for a median duration of 146 days, during which 12.6% underwent minor amputation and 2.5% major amputation. People in the low- and medium-risk categories had major amputation rates of 0.9% and 2.1%, respectively, and negative LR of major LEA of 0.10 and 0.38, respectively, while the people in the high-risk category had an amputation rate of 25.0% and a positive LR of 12.9. The DIAFORA risk groups had a sensitivity of 75.0% and a specificity of 65.7%, with a corresponding AUC of 0.78 (95% CI 0.68-0.87) for the prediction of major LEA.

CONCLUSION

The DIAFORA score is a useful tool for risk stratification of people presenting with a newly occurred DFU, with the external validation presenting results similar to those presented in the original study. The DIAFORA score may guide clinicians towards more individualized DFU treatment regimens.

Near-Infrared Stimuli-Responsive Hydrogel Promotes Cell Migration for Accelerated Diabetic Wound Healing

Diabetic wound healing including diabetic foot ulcers is a major clinical challenge, which could bring an increased level of mortality and morbidity. However, conventional wound dressings exhibit limited healing efficacy due to their lack of active modulation for the healing process. Here, a near-infrared (NIR) stimuli-responsive composite hydrogel dressing with the synergistic effect of both mechanical contraction and epithelial-mesenchymal transition (EMT) was developed to facilitate cell migration and vascularization for diabetic wound healing. In the methacrylated gelatin-based composite hydrogel, N-isopropylacrylamide and polydopamine nanoparticles were incorporated to endow the composite hydrogel with thermosensitive and photothermal properties. Linagliptin (LIN) was loaded into the composite hydrogel, and the drug release rate could be controlled by NIR laser irradiation. NIR-triggered on-demand active contraction of wound area and LIN release for biological stimulation were potentially realized in this responsive system due to the thermally induced sol-gel transition of the composite hydrogel. The release of loaded LIN could effectively promote cell migration by activating EMT and enhancing angiogenesis. In the full-thickness skin defect model, the LIN-loaded composite hydrogel with NIR laser irradiation had the highest wound closure rate as compared with the pure hydrogel and LIN-loaded hydrogel groups. Therefore, this composite hydrogel can serve as an excellent platform for promoting wound healing and will find more practical value in clinical treatment.

What characteristics are most important in stratifying patients into groups with different risk of diabetic foot ulceration?

AIMS/INTRODUCTION

This study aimed to assess if patients can be divided into different strata, and to explore if these correspond to the risk of diabetic foot complications.

MATERIALS AND METHODS

A set of 28 demographic, vascular, neurological and biomechanical measures from 2,284 (1,310 men, 974 women) patients were included in this study. A two-step cluster analysis technique  was utilised to divide the patients into groups, each with similar characteristics.

RESULTS

Only two distinct groups: group 1 (n = 1,199; 669 men, 530 women) and group 2 (n = 1,072; 636 men, 436 women) were identified. From continuous variables, the most important predictors of grouping were: ankle vibration perception threshold (16.9 ± 4.1 V vs 31.9 ± 7.4 V); hallux vibration perception threshold (16.1 ± 4.7 V vs 33.1 ± 7.9 V); knee vibration perception threshold (18.2 ± 5.1 V vs 30.1 ± 6.5 V); average temperature sensation threshold to cold (29.2 ± 1.1°C vs 26.7 ± 0.7°C) and hot (35.4 ± 1.8°C vs 39.5 ± 1.0°C) stimuli, and average temperature tolerance threshold to hot stimuli at the foot (43.4 ± 0.9°C vs 46.6 ± 1.3°C). From categorical variables, only impaired sensation to touch was found to have importance at the highest levels: 87.4% of those with normal sensation were in group 1; whereas group 2 comprised 95.1%, 99.3% and 90.5% of those with decreased, highly-decreased and absent sensation to touch, respectively. In addition, neuropathy (monofilament) was a moderately important predictor (importance level 0.52) of grouping with 26.2% of participants with neuropathy in group 1 versus 73.5% of participants with neuropathy in group 2. Ulceration during follow up was almost fivefold higher in group 2 versus group 1.

CONCLUSIONS

Impaired sensations to temperature, vibration and touch were shown to be the strongest factors in stratifying patients into two groups with one group having almost 5-fold risk of future foot ulceration compared to the other.

A Rare Case of Solitary Neurofibroma Misdiagnosed as Diabetic Foot Ulcer in the Toe Tip Region

Neurofibromas, rare benign tumors of the peripheral nerve sheath, present diagnostic challenges, particularly in diabetic patients with toe ulcers. This case involves a 55-year-old female with type 2 diabetes mellitus who developed an enlarging ulcer on her right second toe. The initial evaluation suggested a diabetic ulcer; however, advanced imaging revealed a mass-like lesion. Partial excision and biopsy confirmed a neurofibroma with spindle cells within the myxoid stroma and S100 protein expression. One month later, total excision and Z-plasty reconstruction were performed under general anesthesia. The patient's postoperative recovery was uneventful, and the patient was discharged without complications. Follow-up revealed successful healing with no recurrence or functional issues. This case highlights the importance of considering neurofibromas in the differential diagnosis of diabetic toe ulcers to avoid misdiagnosis and ensure appropriate management.

Racial/ethnic disparities in chronic wounds: Perspectives on linking upstream factors to health outcomes

This review explores the complex relationship between social determinants of health and the biology of chronic wounds associated with diabetes mellitus, with an emphasis on racial/ethnic disparities. Chronic wounds pose significant healthcare challenges, often leading to severe complications for millions of people in the United States, and disproportionally affect African American, Hispanic, and Native American individuals. Social determinants of health, including economic stability, access to healthcare, education, and environmental conditions, likely influence stress, weathering, and nutrition, collectively shaping vulnerability to chronic diseases, such as obesity and DM, and an elevated risk of chronic wounds and subsequent lower extremity amputations. Here, we review these issues and discuss the urgent need for further research focusing on understanding the mechanisms underlying racial/ethnic disparities in chronic wounds, particularly social deprivation, weathering, and nutrition, to inform interventions to address these disparities.

Health literacy and cognitive function in people with diabetic foot ulcer with focus on knowledge, attitude, and practice in relation to foot self-care

Introduction

Preventative foot self-care is vital for avoiding diabetic foot ulcer episodes and lowering the risk of amputations. Yet, it demands high levels of health literacy and cognitive function.

Objective

To investigate health literacy and cognitive function in persons presenting with a diabetic foot ulcer.

Methods

Participants with type 2 diabetes were recruited from the tertiary foot clinic at Steno Diabetes Center North Denmark. The European Health Literacy Survey Questionnaire and Addenbrooke's Cognitive Examination were applied. A semi-structured interview guide was developed to evaluate foot self-care knowledge, attitude, and practice. The qualitative data were analyzed with a deductive approach based on a qualitative thematic analysis model. Subsequently, an integrated analysis of the quantitative and qualitative results was conducted.

Results

The participants (n = 12) had a mean age of 62.6 ± 8.4 years, and 11 were males. The mean diabetes duration was 15.9 ± 8.9 years. Eight participants had a recurrent diabetic foot ulcer. The health literacy level was sufficient in nine participants, and cognitive function was normal in five participants. Three different profiles related to foot self-care (proactive, active, or passive, respectively) were constructed by the final integrated analysis: a proactive profile refers to taking preventative action in concordance with knowledge and attitude, an active profile to taking action in response to a situation, but challenged by conflicting levels of knowledge and attitude, and a passive profile to not taking action.

Conclusion

The study suggests that people presenting with a diabetic foot ulcer have different foot self-care profiles based on person-specific health literacy, cognitive function, and knowledge, attitude, and practice element characteristics, highlighting the need for individualized education and intervention strategy instead of a one-size-fits-all approach.

Relationship between Prognostic Nutritional Index and Amputation in Patients with Diabetic Foot Ulcer

The prognostic nutritional index (PNI) is a new marker used to assess a patient's nutritional and immune status. It is calculated using serum albumin levels and total lymphocyte count. The aim of this study was to investigate the relationship between PNI and amputation in patients with diabetic foot ulcer (DFU). Patients with DFU were enrolled in this retrospective study. In our study, a total of 386 patient data, of 110 (28.5%) amputated and 276 (71.5%) non-amputated patients, were statistically analyzed. PNI values were significantly lower in the amputated patient group than in the non-amputee patient group (p < 0.001). According to the ROC analysis results, PNI was significant in the prediction of amputation at an excellent level (AUC = 0.937 (0.911-0.963), p < 0.001). The optimal cut-off point for PNI was found to be 39,005. There was classification success for this cut-off point: sensitivity was calculated as 82.7% (74.1-89) and specificity as 93.1% (89.3-95.7). In the multivariate model, the odds ratio (OR) (95% CI) was calculated as 81.8 (38.5-173.7) for PNI. The PNI was associated with an increase in amputation rate in patients with DFU. By using PNI, patients can be directed to advanced centers and have access to early and appropriate interventions.

Diabetic foot ulcers risk prediction in patients with type 2 diabetes using classifier based on associations rule mining

Identifying diabetic patients at risk of developing foot ulcers, as one of the most significant complications of diabetes, is a crucial healthcare concern. This study aimed to develop an associative classification model (CBA) using the Apriori algorithm to predict diabetic foot ulcers (DFU). This retrospective cohort study included 666 patients with type 2 diabetes referred to Shahid Beheshti Hospital in Iran between April 2020 and August 2022, of which 279 (42%) had DFU. Data on 29 specific baseline features were collected, which were preprocessed by discretizing numerical variables based on medical cutoffs. The target variable was the occurrence of DFU, and the minimum support, confidence, and lift thresholds were set to 0.01, 0.7, and 1, respectively. After data preparation and cleaning, a CBA model was created using the Apriori algorithm, with 80% of the data used as a training set and 20% as a testing set. The accuracy and AUC (area under the roc curve) measure were used to evaluate the performance of the model. The CBA model discovered a total of 146 rules for two patient groups. Several factors, such as longer duration of diabetes over 10 years, insulin therapy, male sex, older age, smoking, addiction to other drugs, family history of diabetes, higher body mass index, physical inactivity, and diabetes complications such as proliferative and non-proliferative retinopathy and nephropathy, were identified as major risk factors contributing to the development of DFU. The CBA model achieved an overall accuracy of 96%. Also, the AUC value was 0.962 (95%CI 0.924, 1.000). The developed model has a high accuracy in predicting the risk of DFU in patients with type 2 diabetes. The creation of accurate predictive models for DFU has the potential to significantly reduce the burden of managing recurring ulcers and the need for amputation, which are significant health concerns associated with diabetes.

Predicting diabetic foot ulceration using routinely collected data in a foot clinic. What level of prognostic accuracy can be achieved?

This study aimed to investigate the efficacy of using routinely collected clinical data in predicting the risk of diabetic foot ulcer (DFU). The first objective was to develop a prognostic model based on the most important risk factors objectively selected from a set of 39 clinical measures. The second objective was to compare the prediction accuracy of the developed model against that of a model based on only the 3 risk factors that were suggested in the systematic review and meta-analyses study (PODUS). In a cohort study, a set of 12 continuous and 27 categorical data from patients (n = 203 M/F:99/104) who attended a specialised diabetic foot clinic were collected at baseline. These patients were then followed-up for 24 months during which 24 (M/F:17/7) patients had DFU. Multivariate logistic regression was used to develop a prognostic model using the identified risk factors that achieved p < 0.2 based on univariate logistic regression. The final prognostic model included 4 risk factors (Adjusted-OR [95% CI]; p) in total. Impaired sensation (116.082 [12.06-1117.287]; p = 0.000) and presence of callus (6.257 [1.312-29.836]; p = 0.021) were significant (p < 0.05), while having dry skin (5.497 [0.866-34.89]; p = 0.071) and Onychomycosis (6.386 [0.856-47.670]; p = 0.071) that stayed in the model were not significant. The accuracy of the model with these 4 risk factors was 92.3%, where sensitivity and specificity were 78.9%, and 94.0% respectively. The 78.9% sensitivity of our prognostic 4-risk factor model was superior to the 50% sensitivity that was achieved when the three risk factors proposed by PODUS were used. Also our proposed model based on the above 4 risk factors showed to predict the DFU with higher overall prognostic accuracy. These findings have implications for developing prognostic models and clinical prediction rules in specific patient populations to more accurately predict DFU.

[Technical Orthopedics - Chronic Diabetic Foot Wounds]

Technical Orthopedics - Chronic Diabetic Foot Wounds Abstract: Chronic foot wounds are a very common and a growing problem. This review focuses on the treatment and the prophylaxis of diabetic foot ulcers from the perspective of technical orthopedics. Diabetic foot ulcers are of great importance for those affected, in particular because of the risk of infections and resulting amputations. With a good prophylaxis and consistent treatment, these complications can often be avoided.

Using a contralateral shoe lift to reduce gait deterioration during an offloading fast-walk setting in diabetic peripheral neuropathy: A comparative feasibility study

AIMS

Diabetic peripheral neuropathy (DPN) is a predictor of foot ulcers and leads to sedentary behaviour. This comparative study evaluated gait and feasibility of a 20-minute fast walk, at 40-60% of cardiopulmonary capacity, in individuals with DPN wearing an offloading boot and a contralateral shoe balancer.

METHODS

Gait parameters were measured with inertial sensors on 32 individuals (group with DPN [n = 16], group with diabetes but without DPN [n = 9], and a group without diabetes/DPN [n = 7]). Feasibility was assessed by feedback on perceived effort and adverse events. Gait outcomes were compared between groups with or without a shoe balancer using one-way ANOVAs.

RESULTS

The three groups were equivalent in terms of activity level and age and gender except for the body mass index. Both groups with diabetes exhibited minimal decreased gait speed (p > 0.005) and the DPN group exhibited increased double-support percentage (+4.6%, p = 0.01) while walking with an offloading boot and contralateral shoe balancer. The use of a contralateral shoe balancer reduced gait asymmetry. Lower physical activity level was associated with further gait deterioration in all groups. Few adverse events were reported, and 91% of participants reported that the proposed activity would be feasible daily.

CONCLUSIONS

The offloading boot deteriorated gait function, but a contralateral shoe balancer minimized its impact, especially in the context of physical activity in people with diabetes and DPN.

Function and mechanism of mesenchymal stem cells in the healing of diabetic foot wounds

Diabetes has become a global public health problem. Diabetic foot is one of the most severe complications of diabetes, which often places a heavy economic burden on patients and seriously affects their quality of life. The current conventional treatment for the diabetic foot can only relieve the symptoms or delay the progression of the disease but cannot repair damaged blood vessels and nerves. An increasing number of studies have shown that mesenchymal stem cells (MSCs) can promote angiogenesis and re-epithelialization, participate in immune regulation, reduce inflammation, and finally repair diabetic foot ulcer (DFU), rendering it an effective means of treating diabetic foot disease. Currently, stem cells used in the treatment of diabetic foot are divided into two categories: autologous and allogeneic. They are mainly derived from the bone marrow, umbilical cord, adipose tissue, and placenta. MSCs from different sources have similar characteristics and subtle differences. Mastering their features to better select and use MSCs is the premise of improving the therapeutic effect of DFU. This article reviews the types and characteristics of MSCs and their molecular mechanisms and functions in treating DFU to provide innovative ideas for using MSCs to treat diabetic foot and promote wound healing.

Risk prediction models for diabetic foot ulcer development or amputation: a review of reviews

BACKGROUND

In adults with diabetes, diabetic foot ulcer (DFU) and amputation are common and associated with significant morbidity and mortality.

PURPOSE

Identify tools predicting risk of DFU or amputation that are prognostically accurate and clinically feasible.

METHODS

We searched for systematic reviews (SRs) of tools predicting DFU or amputation published in multiple databases from initiation to January, 2023. We assessed risk of bias (ROB) and provided a narrative review of reviews describing performance characteristics (calibration and discrimination) of prognostically accurate tools. For such tools, we additionally reviewed original studies to ascertain clinical applicability and usability (variables included, score calculation, and risk categorization).

RESULTS

We identified 3 eligible SRs predicting DFU or amputation risk. Two recent SRs (2020 and 2021) were rated as moderate and low ROB respectively. Four risk prediction models - Boyko, Martins-Mendes (simplified), Martins-Mendes (original), and PODUS 2020 had good prognostic accuracy for predicting DFU or amputation over time horizons ranging from 1- to 5-years. PODUS 2020 predicts absolute average risk (e.g., 6% risk of DFU at 2 years) and consists of 3-binary variables with a simple, summative scoring (0-4) making it feasible for clinic use. The other 3 models categorize risk subjectively (e.g., high-risk for DFU at 3 years), include 2-7 variables, and require a calculation device. No data exist to inform rescreening intervals. Furthermore, the effectiveness of targeted interventions in decreasing incidence of DFU or amputation in response to prediction scores is unknown.

CONCLUSIONS

In this review of reviews, we identified 4 prognostically accurate models that predict DFU or amputation in persons with diabetes. The PODUS 2020 model, predicting absolute average DFU risk at 2 years, has the most favorable prognostic accuracy and is clinically feasible. Rescreening intervals and effectiveness of intervention based on prediction score are uncertain.

Effects of neutrophil‐to‐lymphocyte ratio, serum calcium, and serum albumin on prognosis in patients with diabetic foot

The purpose of this study is to investigate the predictive value of neutrophil-to-lymphocyte ratio (NLR), serum calcium, and serum albumin on the prognosis of patients with diabetic foot. A total of 156 patients who were treated in the Department of Burn and Plastic Surgery of Qilu Hospital of Shandong University from 1 January 2014 to 1 August 2020 were selected. All the patients were randomly divided into a healing group, minor amputation group, major amputation group, and death group according to their treatment outcomes. The levels of NLR, serum calcium and serum albumin in each group were examined and compared. The correlations between NLR, serum calcium, and serum albumin with the prognosis of diabetic foot were analysed to investigate their predictive effects on the prognosis of diabetic foot. The results of one-way ANOVA showed that among the 4 groups of patients, the difference in NLR values between the healing group and the minor amputation group was slightly smaller, but they were significantly different from the major amputation group and the death group, respectively. There was no significant difference in serum calcium levels between the healing group and the minor amputation group, but the serum calcium levels of the major amputation group and the death group gradually decreased. The levels of NLR in the 4 groups gradually increased, while the albumin levels gradually decreased. Spearman's rank correlation test indicated that NLR was significantly related to the prognosis of patients with diabetic foot. The group with higher NLR had a worse prognosis in diabetic foot patients. Serum calcium and serum albumin were strongly correlated with the prognosis of patients with diabetic foot. The group with lower serum calcium and serum albumin values had a worse prognosis in diabetic foot patients. The areas under the receiver operator characteristic curve of NLR, serum calcium and serum albumin were 0.901, 0.803, and 0.816, respectively. NLR, serum calcium and serum albumin can be used as reliable indicators to predict the prognosis of diabetic foot. Preoperative diabetic foot patients with higher NLR values or lower serum calcium and serum albumin have a poorer prognosis.

A scoping review protocol to map the evidence on the risks and benefits of population based diabetic foot screening

Background: Diabetic foot ulcers are one of the most common lower extremity complications of diabetes, with the lifetime risk of a person developing a DFU estimated to be as high as 34%. It is recommended that those with diabetes receive an annual review of their feet, by a trained healthcare professional, to identify risk factors for ulceration and allow for subsequent risk stratification, patient education and provision of appropriate care to prevent ulceration and amputation. Internationally, while many countries have a diabetic foot care pathway, it is not a structured population health screening programme unlike other areas of preventive care for people with diabetes such as retinopathy screening. A structured diabetic foot screening pathway could allow for earlier identification of the at-risk foot. However, the introduction of any population screening programme should meet the Wilson and Jungner principles of screening. This paper presents a protocol for a scoping review of existing evidence on screening for the at-risk-foot against the Wilson and Junger principles. Methods: The scoping review will be conducted in line with the six-stage methodological framework by Arksey & O'Mally and the Joanna Briggs Institute (JBI) scoping review methodology. Medline (EBSCO), Scopus, ScienceDirect and EMBASE databases will be searched. Studies relating to the burden of diabetic foot ulcers, their pathophysiology and screening tests for peripheral neuropathy and peripheral artery disease, and screening programmes will be included. A data extraction tool will be used to facilitate a chronological narrative synthesis of results. Results: These will be reported in line with the Preferred Reporting Items for Systematic Reviews and Meta-analyses extension for Scoping Reviews (PRISMA-ScR). Conclusion: This scoping review will evaluate and map the evidence surrounding diabetic foot ulcers using the Wilson and Jungner principles of screening as a framework.

Prediction of callus and ulcer development in patients with diabetic peripheral neuropathy by isosceles triangle-forming tuning fork

Objectives:

Tuning fork vibration sensation testing is widely used as a diagnostic test to detect diabetic neuropathy. However, evidence-based literature indicates that reliability between examiners is low. Attaching isosceles triangle diagrams on tuning forks lowers the discrepancy between examiners. This study aimed to analyze the relationship between vibration sensation measurement using an improved tuning fork and the presence of callus and wound development in patients with diabetic peripheral neuropathy.

Methods:

Participants included 56 general older adults and 52 patients with diabetic peripheral neuropathy. The methods included confirmation of the presence or absence of callus, range of motion of the ankle and the first metatarsophalangeal joint, vibratory sensitivity of the medial malleolus and the dorsal aspect of the first distal phalanx using an improved tuning fork, and touch-pressure sensitivity of the plantar aspect of the hallux. Patients with diabetic peripheral neuropathy were followed up for 3 years to check for the presence or absence of wounds.

Results:

When compared with the general older adults, the patients with diabetic peripheral neuropathy had significantly lower touch-pressure sensitivity (p < 0.01), vibratory sensitivity at the distal phalanx (p < 0.01) and medial malleolus (p < 0.01), ankle dorsiflexion range of motion (p < 0.01), and metatarsophalangeal joint extension range of motion (p < 0.01). The area under the receiver operating characteristic curve with callus formation was 0.93 for the medial malleolus and 0.96 for the distal phalanx, indicating that the accuracy of the distal phalanx was higher (p < 0.01) than the medial malleolus. According to the Cox proportional hazard analysis, the vibratory sensitivity of the distal phalanx was a significant risk factor for ulcer development (p < 0.05).

Conclusion:

These findings suggest that the vibration sensation test, which we improved via the technique described in this study, is useful for predicting the occurrence of callus and ulcer.

Diabetes Status is Associated With Plantar Soft Tissue Stiffness Measured Using Ultrasound Reverberant Shear Wave Elastography Approach

INTRODUCTION

The purpose of this study was to investigate the association between the mechanical properties of plantar soft tissue and diabetes status.

METHOD

51 (M/F: 21/30) participants with prediabetes onset (fasting blood sugar [FBS] level > 100 mg/dL), age >18 years, and no lower limb amputation were recruited after ethical approval was granted from Pontificia Universidad Catolica del Peru ethical review board. Ultrasound reverberant shear wave elastography was used to assess the soft tissue stiffness at the 1st metatarsal head (MTH), 3rd MTH, and the heel at both feet.

RESULTS

Spearman's rank-order correlation (rho) test indicated a significant (P < .05) positive correlations between FBS level and the plantar soft tissue shear wave speed at the 1st MTH: rho = 0.402 (@400 Hz), rho = 0.373 (@450 Hz), rho = 0.474 (@500 Hz), rho= 0.395 (@550 Hz), and rho = 0.326 (@600 Hz) in the left foot and rho = 0.364 (@450 Hz) in the right foot. Mann-Whitney U test indicated a significantly (P < .05) higher shear wave speed in the plantar soft tissue with the following effect sizes (r) at the 1st MTH of the left foot at all tested frequencies: r = 0.297 (@450 Hz), r = 0.345 (@500 Hz), r = 0.322 (@550 Hz), and r = 0.275 (@600 Hz), and at the 1st MTH of right foot r = 0.286 (@400 Hz) in diabetes as compared with the age and body mass index matched prediabetes group.

CONCLUSION

An association between fasting blood sugar level and the stiffness of the plantar soft tissue with higher values of shear wave speed in diabetes versus prediabetes group was observed. This indicated that the proposed approach can improve the assessment of the severity of diabetic foot complications with potential implications in patient stratification.

Preulcerous Risk Situation in Diabetic Foot Syndrome: Proposal for a Simple Ulcer Prevention Score

BACKGROUND

Preulcerous risk situations in patients with diabetes are often undiagnosed and care administered too late. Even with regular medical check-ups and status documentation, foot examinations have not been given enough attention. Diagnosing an individual patients' risk of developing diabetic foot ulcers may increase vigilance for diabetic foot syndrome (DFS), and the appropriate prevention measures matching the risk involved may prevent the emergence of diabetic ulcers. The classical DFS risk factors are well established and have been extensively covered in the literature; however, there is a lack of efficient screening tools that could be used for a rapid assessment of diabetic foot ulcer risk.

METHODS

A methodical literature search was conducted to assess relevant publications for the preparation of a simple risk score for amputation related to diabetic foot ulcer. We then analyzed the risk factors for predictive value as odds ratios in foot ulcers and/or amputation. We used the available data to deduce a mean value to reflect the authors' consensus.

RESULTS

In view of the current literature on the matter, we have developed a semi-quantitative scoring system using just a few items to allow rapid and visual risk assessment for diabetic foot ulcers alongside recommendations for prevention and a sensible follow-up strategy to match the risk.

CONCLUSION

This relatively simple score enables rapid risk classification for patients that can ease the way for both physicians and patients in gaining an insight into individual risk situations. The score provides more effective preventative measures for high-risk patients against future complications.

Development of a prediction model for foot ulcer recurrence in people with diabetes using easy-to-obtain clinical variables

INTRODUCTION

We aimed to develop a prediction model for foot ulcer recurrence in people with diabetes using easy-to-obtain clinical variables and to validate its predictive performance in order to help risk assessment in this high-risk group.

RESEARCH DESIGN AND METHODS

We used data from a prospective analysis of 304 people with foot ulcer history who had 18-month follow-up for ulcer outcome. Demographic, disease-related and organization-of-care variables were included as potential predictors. Two logistic regression prediction models were created: model 1 for all recurrent foot ulcers (n=126 events) and model 2 for recurrent plantar foot ulcers (n=70 events). We used 10-fold cross-validation, each including five multiple imputation sets for internal validation. Performance was assessed in terms of discrimination using area under the receiver operating characteristic curve (AUC) (0-1, 1=perfect discrimination), and calibration with the Brier Score (0-1, 0=complete concordance predicted vs observed values) and calibration graphs.

RESULTS

Predictors in model 1 were: a younger age, more severe peripheral sensory neuropathy, fewer months since healing of previous ulcer, presence of a minor lesion, use of a walking aid and not monitoring foot temperatures at home. Mean AUC for model 1 was 0.69 (2SD 0.040) and mean Brier Score was 0.22 (2SD 0.011). Predictors in model 2 were: a younger age, plantar location of previous ulcer, fewer months since healing of previous ulcer, presence of a minor lesion, consumption of alcohol, use of a walking aid, and foot care received in a university medical center. Mean AUC for model 2 was 0.66 (2SD 0.023) and mean Brier Score was 0.16 (2SD 0.0048).

CONCLUSIONS

These internally validated prediction models predict with reasonable to good calibration and fair discrimination who is at highest risk of ulcer recurrence. The people at highest risk should be monitored more carefully and treated more intensively than others.

TRIAL REGISTRATION NUMBER

NTR5403.

High Incidence of Adverse Outcomes in Haemodialysis Patients with Diabetes with or without Diabetic Foot Syndrome: A 5-Year Observational Study in Lleida, Spain

Background: We evaluated whether, in subjects receiving haemodialysis (HD), the presence of diabetic foot syndrome (DFS) was associated with increased mortality compared with subjects with diabetes mellitus (DM) without DFS and with non-diabetic subjects. Methods: Retrospective, observational study in 220 subjects followed for six years. We calculated and compared the frequency and 5-year cumulative incidence of all-cause mortality, cardiovascular (CV) mortality, CV events, major adverse CV events (MACE), and new foot ulcer (FU) or amputation. We also examined prognostic factors of all-cause and CV mortality based on baseline characteristics. Results: DM patients had a 1.98 times higher probability of all-cause mortality than those without DM (p = 0.001) and 2.42 times higher likelihood of CV mortality and new FU or amputation (p = 0.002 and p = 0.008, respectively). In the DM cohort, only the risk of a new FU or amputation was 2.69 times higher among those with previous DFS (p = 0.021). In patients with DM, older age was the only predictor of all-cause and CV mortality (p = 0.001 and p = 0.014, respectively). Conclusions: Although all-cause and CV mortality were increased on HD subjects with DM, the presence of DFS did not modify the excess risk. Additional studies are warranted to further explore the impact of DFS in subjects with DM undergoing HD.

Risk assessments and structured care interventions for prevention of foot ulceration in diabetes: development and validation of a prognostic model

BACKGROUND

Diabetes-related foot ulcers give rise to considerable morbidity, generate a high monetary cost for health and social care services and precede the majority of diabetes-related lower extremity amputations. There are many clinical prediction rules in existence to assess risk of foot ulceration but few have been subject to validation.

OBJECTIVES

Our objectives were to produce an evidence-based clinical pathway for risk assessment and management of the foot in people with diabetes mellitus to estimate cost-effective monitoring intervals and to perform cost-effectiveness analyses and a value-of-information analysis.

DESIGN

We developed and validated a prognostic model using predictive modelling, calibration and discrimination techniques. An overview of systematic reviews already completed was followed by a review of randomised controlled trials of interventions to prevent foot ulceration in diabetes mellitus. A review of the health economic literature was followed by the construction of an economic model, an analysis of the transitional probability of moving from one foot risk state to another, an assessment of cost-effectiveness and a value-of-information analysis.

INTERVENTIONS

The effects of simple and complex interventions and different monitoring intervals for the clinical prediction rules were evaluated.

MAIN OUTCOME MEASURE

The main outcome was the incidence of foot ulceration. We compared the new clinical prediction rules in conjunction with the most effective preventative interventions at different monitoring intervals with a 'treat-all' strategy.

DATA SOURCES

Data from an electronic health record for 26,154 people with diabetes mellitus in one Scottish health board were used to estimate the monitoring interval. The Prediction Of Diabetic foot UlcerationS (PODUS) data set was used to develop and validate the clinical prediction rule.

REVIEW METHODS

We searched for eligible randomised controlled trials of interventions using search strategies created for Ovid® (Wolters Kluwer, Alphen aan den Rijn, the Netherlands), MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials. Randomised controlled trials in progress were identified via the International Standard Randomised Controlled Trial Number Registry and systematic reviews were identified via PROSPERO. Databases were searched from inception to February 2019.

RESULTS

The clinical prediction rule was found to accurately assess the risk of foot ulceration. Digital infrared thermometry, complex interventions and therapeutic footwear with offloading devices were found to be effective in preventing foot ulcers. The risk of developing a foot ulcer did not change over time for most people. We found that interventions to prevent foot ulceration may be cost-effective but there is uncertainty about this. Digital infrared thermometry and therapeutic footwear with offloading devices may be cost-effective when used to treat all people with diabetes mellitus regardless of their ulcer risk.

LIMITATIONS

The threats to the validity of the results in some randomised controlled trials in the review and the large number of missing data in the electronic health record mean that there is uncertainty in our estimates.

CONCLUSIONS

There is evidence that interventions to prevent foot ulceration are effective but it is not clear who would benefit most from receiving the interventions. The ulceration risk does not change over an 8-year period for most people with diabetes mellitus. A change in the monitoring interval from annually to every 2 years for those at low risk would be acceptable.

FUTURE WORK RECOMMENDATIONS

Improving the completeness of electronic health records and sharing data would help improve our knowledge about the most clinically effective and cost-effective approaches to prevent foot ulceration in diabetes mellitus.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42016052324.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 62. See the NIHR Journals Library website for further project information.

Competitive neural layer-based method to identify people with high risk for diabetic foot

BACKGROUND AND OBJECTIVE

To automatically identify patients with diabetes mellitus (DM) who have high risk of developing diabetic foot, via an unsupervised machine learning technique.

METHODS

We collected a new database containing 54 known risk factors from 250 patients diagnosed with diabetes mellitus. The database also contained a separate validation cohort composed of 73 subjects, where the perceived risk was annotated by expert nurses. A competitive neuron layer-based method was used to automatically split training data into two risk groups.

RESULTS

We found that one of the groups was composed of patients with higher risk of developing diabetic foot. The dominant variables that described group membership via our method agreed with the findings from other studies, and indicated a greater risk for developing such a condition. Our method was validated on the available test data, reaching 71% sensitivity, 100% specificity, and 90% accuracy.

CONCLUSIONS

Unsupervised learning may be deployed to screen patients with diabetes mellitus, pointing out high-risk individuals who require priority follow-up in the prevention of diabetic foot with very high accuracy. The proposed method is automatic and does not require clinical examinations to perform risk assessment, being solely based on the information of a questionnaire answered by patients. Our study found that discriminant variables for predicting risk group membership are highly correlated with expert opinion.

Risk factors affecting amputation in diabetic foot

Background

A diabetic foot is the most common cause of non-traumatic lower extremity amputations (LEA). The study seeks to assess the risk factors of amputation in patients with diabetic foot ulcers (DFU).

Methods

The study was conducted on 351 patients with DFUs from January 2010 to December 2018. Their demographic characteristics, disease history, laboratory data, ankle-brachial index, Wagner classification, osteomyelitis, sarcopenia index, and ulcer sizes were considered as variables to predict outcome. A chi-square test and multivariate logistic regression analysis were performed to test the relationship of the data gathered. Additionally, the subjects were divided into two groups based on their amputation surgery.

Results

Out of the 351 subjects, 170 required LEA. The mean age of the subjects was 61 years and the mean duration of diabetes was 15 years; there was no significant difference between the two groups in terms of these averages. Osteomyelitis (hazard ratio [HR], 6.164; 95% confidence interval [CI], 3.561−10.671), lesion on percutaneous transluminal angioplasty (HR, 2.494; 95% CI, 1.087−5.721), estimated glomerular filtration rate (eGFR; HR, 0.99; 95% CI, 0.981−0.999), ulcer size (HR, 1.247; 95% CI, 1.107−1.405), and forefoot ulcer location (HR, 2.475; 95% CI, 0.224−0.73) were associated with risk of amputation.

Conclusion

Osteomyelitis, peripheral artery disease, chronic kidney disease, ulcer size, and forefoot ulcer location were risk factors for amputation in diabetic foot patients. Further investigation would contribute to the establishment of a diabetic foot risk stratification system for Koreans, allowing for optimal individualized treatment.

Predicting the risk of future diabetic foot ulcer occurrence: a prospective cohort study of patients with diabetes in Tanzania

OBJECTIVES

The aim of this study was to identify the parameters that predict the risk of future foot ulcer occurrence in patients with diabetes.

RESEARCH DESIGN AND METHODS

1810 (male (M)/female (F): 1012/798) patients, with no foot ulcer at baseline, participated in this study. Data from a set of 28 parameters were collected at baseline. During follow-up, 123 (M/F: 68/55) patients ulcerated. Survival analyses together with logistic regression were used to identify the parameters that could predict the risk of future diabetic foot ulcer occurrence.

RESULTS

A number of parameters (HR (95% CI)) including neuropathy (2.525 (1.680 to 3.795)); history of ulceration (2.796 (1.029 to 7.598)); smoking history (1.686 (1.097 to 2.592)); presence of callus (1.474 (0.999 to 2.174)); nail ingrowth (5.653 (2.078 to 15.379)); foot swelling (3.345 (1.799 to 6.218)); dry skin (1.926 (1.273 to 2.914)); limited ankle (1.662 (1.365 to 2.022)) and metatarsophalangeal (MTP) joint (2.745 (1.853 to 4.067)) ranges of motion; and decreased (3.141 (2.102 to 4.693)), highly decreased (5.263 (1.266 to 21.878)), and absent (9.671 (5.179 to 18.059)) sensation to touch; age (1.026 (1.010 to 1.042)); vibration perception threshold (1.079 (1.060 to 1.099)); duration of diabetes (1.000 (1.000 to 1.000)); and plantar pressure at the first metatarsal head (1.003 (1.001 to 1.005)), temperature sensation (1.019 (1.004 to 1.035)) and temperature tolerance (1.523 (1.337 to 1.734)) thresholds to hot stimuli and blood sugar level (1.027 (1.006 to 1.048)) were all significantly associated with increased risk of ulceration. However, plantar pressure underneath the fifth toe (0.990 (0.983 to 0.998)) and temperature sensation (0.755 (0.688 to 0.829)) and temperature tolerance (0.668 (0.592 to 0.0754)) thresholds to cold stimuli showed to significantly decrease the risk of future ulcer occurrence. Multivariate survival model indicated that nail ingrowth (4.42 (1.38 to 14.07)); vibration perception threshold (1.07 (1.04 to 1.09)); dry skin status (4.48 (1.80 to 11.14)); and temperature tolerance threshold to warm stimuli (1.001 (1.000 to 1.002)) were significant predictors of foot ulceration risk in the final model. The mean time to ulceration was significantly (p<0.05) shorter for patients with: dry skin (χ²=11.015), nail ingrowth (χ²=14.688), neuropathy (χ²=21.284), or foot swelling (χ²=16.428).

CONCLUSION

Nail ingrowth and dry skin were found to be strong indicators of vulnerability of patients to diabetic foot ulceration. Results highlight that assessments of neuropathy in relation to both small and larger fiber impairment need to be considered for predicting the risk of diabetic foot ulceration.

Prevention of foot ulcers in the at-risk patient with diabetes: a systematic review

Prevention of foot ulcers in patients with diabetes is important to help reduce the substantial burden on both patient and health resources. A comprehensive analysis of reported interventions is needed to better inform healthcare professionals about effective prevention. The aim of this systematic review is to investigate the effectiveness of interventions to help prevent both first and recurrent foot ulcers in persons with diabetes who are at risk for this complication. We searched the available medical scientific literature in PubMed, EMBASE, CINAHL, and the Cochrane databases for original research studies on preventative interventions. We screened trial registries for additional studies not found in our search and unpublished trials. Two independent reviewers assessed data from controlled studies for methodological quality, and extracted and presented this in evidence and risk of bias tables. From the 13,490 records screened, 35 controlled studies and 46 non-controlled studies were included. Few controlled studies, which were of generally low to moderate quality, were identified on the prevention of a first foot ulcer. For the prevention of recurrent plantar foot ulcers, there is benefit for the use of daily foot skin temperature measurements, and for therapeutic footwear with demonstrated plantar pressure relief, provided it is consistently worn by the patient. For prevention of ulcer recurrence, there is some evidence for providing integrated foot care, and no evidence for a single session of education.Surgical interventions have been shown effective in selected patients, but the evidence base is small. Foot-related exercises do not appear to prevent a first foot ulcer. A small increase in the level of weight-bearing daily activities does not seem to increase the risk for foot ulceration. The evidence base to support the use of specific self-management and footwear interventions for the prevention of recurrent plantar foot ulcers is quite strong. The evidence is weak for the use of other, sometimes widely applied, interventions, and is practically non-existent for the prevention of a first foot ulcer and non-plantar foot ulcer.

Relationship of ankle-brachial index, vibration perception threshold, and current perception threshold to glycemic variability in type 2 diabetes

To explore the relationship of glycemic variability with lower extremity arterial disease (LEAD) and diabetic peripheral neuropathy (DPN).Seventy-eight patients with type 2 diabetes were enrolled. All patients underwent 72-hour dynamic blood glucose monitoring and obtained mean amplitude of glycemic excursions (MAGE), mean of daily differences (MODD), standard deviation of blood glucose (SD), largest amplitude of glycemic excursion (LAGE), mean blood glucose (MBG), T≥10.0 (percentage of time for blood glucose levels ≥10.0 mmol/L), T≤3.9 (percentage of time for blood glucose levels ≤3.9 mmol/L), and other glycemic variability parameters. In the meanwhile, in order to explore the correlation of glycemic variability parameters with ankle-brachial index (ABI), vibration perception threshold (VPT), and current perception threshold (CPT), all patients underwent quantitative diabetic foot screening, including ABI for quantitative assessment of lower extremity arterial lesions and VPT and CPT for quantitative assessment of peripheral neuropathy.Patients were divided into abnormal CPT group (n = 21) and normal CPT group (n = 57) according to the CPT values. Compared with the normal CPT group, abnormal CPT group showed significantly higher levels of HbA1c, longer duration of diabetes, and higher levels of T≤3.9 (P < .05). However, there was no significant difference of MAGE, SD, LAGE, MODD, and other glycemic variability parameters between abnormal CPT group and normal CPT group (P > .05). Pearson correlation analysis or Spearman correlation analysis showed that ABI negatively correlated with MBG, T≥10.0, SD, LAGE, and MAGE (P < .05), but no correlation of ABI with T≤3.9 and MODD (P > .05) was shown. VPT showed a positive correlation with T≥10.0 (P < .05), but no correlation with other glycemic variability parameters (P > .05). There was no correlation between the other CPT values and the glycemic variability parameters (P > .05), except that the left and right 250 Hz CPT values were positively correlated with T≤3.9 (P > .05).The higher the blood glucose levels, the severer the degree of LEAD and DPN lesions; the higher the incidence of hypoglycemia, the severer the degree of DPN lesions; the greater the fluctuation of blood glucose, the severer the degree of LEAD lesions. However, the glycemic variability was not significantly correlated with DPN.

Evaluation of the risk of diabetic peripheral neuropathy: Design and validation of the NeuDiaCan nursing screening procedure

OBJECTIVE

To design and validate a nursing screening procedure for diabetic peripheral neuropathy in primary care.

METHODS

The study was carried out in three phases. 1)Construction of an item bank to form the procedure with an exit score describing the patient's clinical situation. 2)Test and reduction of the initial tentative procedure on a sample of 50 patients using community nurse consultations, eliminating the components with low inter-intra nurse reliability. 3)Validation of the version of the procedure obtained in the previous step on a sample of 106 patients. Calculation of validity and reliability by eliminating components with low criterion validity with respect to the results of the diagnostic electromyography used as a reference standard. Cut-off points were estimated for the use of the procedure as a screening tool, predictive values, performance, internal consistency and inter-nurse reliability.

RESULTS

The initial tentative procedure consisted of 12 components that were reduced to 10. In the process of validation of this second version the procedure was simplified again, eventually comprising 6 components, with a cut-off point of 2.5 in its output scale, the point at which it reaches adequate values of sensitivity and negative predictors to be used as a screening instrument. For this cut-off point the inter-intra nurse reliability, criterion validity and predictive validity reached acceptable values.

CONCLUSIONS

NeuDiaCan as a nursing screening procedure for diabetic peripheral neuropathy in primary care is valid, reliable and easy to use.

Diabetic foot self-care and concordance of 3diabetic foot risk stratification systems in a basic health area of Gran Canaria

OBJECTIVE

To assess the level of self-care in the population with diabetes and determine the risk of diabetic foot lesions through the use of 3stratification systems as well as to establish the degree of concordance between these systems.

METHOD

Observational, cross-sectional and descriptive study carried out in the Basic Health Area of Santa Brígida (Gran Canaria-Canary Islands-Spain) in people diagnosed with diabetes (DM Type 1/DM Type 2) (n=182). Interview, physical examination, review of clinical history and completion of the Diabetic Foot Self-Care questionnaire of the University of Malaga were carried out. The risk stratification was then calculated using 3systems (System of the National Institute for Health Care Excellence, Classification of the International Working Group on the Diabetic Foot and High-Risk Diabetic Foot-60-Second Tool©-2012). The Kappa index was calculated to study the concordance between systems, the relative risk of negative screening of one method against another was estimated and the exact Fisher test to establish whether there were differences.

RESULTS

30.2% of diabetics had a low level of self-care, 45.1% a medium level and 24.7% a high level. The risk levels calculated were: National Institute for Health Care Excellence Classification (Negative Risk 71.4%-Positive Risk 28.6%), International Working Group on the Diabetic Foot Classification (Negative Risk 67.0%-Positive Risk 33.0%) and High-Risk Diabetic Foot-60-Second Tool© (Negative Risk 62.6%-Positive Risk 37.4%).

CONCLUSIONS

All 3systems have good concordance with each other. The High-Risk Diabetic Foot-60-Second Tool© only distinguishes 2levels of risk but detects a higher percentage of people at risk. The Diabetic Foot Self-Care questionnaire of the University of Malaga may be useful in the context of Primary Care to assess the level of self-care of people with diabetes.

Neurovascular Response to Pressure in Patients With Diabetic Foot Ulcer

Diabetic foot ulcer (DFU) is a problem worldwide, and prevention is crucial. We hypothesized that the inability of the skin to respond to pressure is involved in DFU pathogenesis and could be an important predictive factor to take into account. We included 29 patients with DFU and 30 patients with type 2 diabetes without DFU. Neuropathy and skin blood flow at rest were assessed in response to acetylcholine, sodium nitroprusside, local heating (42°C), and to nonnoxious locally applied pressure. Results were compared with those obtained from 10 healthy age-matched control subjects. Vasodilatation in response to pressure was significantly impaired in both groups with diabetes compared with healthy subjects. The vasodilator capacity to pressure was significantly lower in patients with DFU compared with those without DFU, despite the absence of significant difference in cutaneous pressure perception threshold and vascular reactivity to acetylcholine, sodium nitroprusside, and heat. This pronounced alteration of neurovascular response to pressure in patients with DFU is a good marker of skin vulnerability and could be used to better predict individuals at risk.

An integrative review of therapeutic footwear for neuropathic foot due to diabetes mellitus

BACKGROUND

Therapeutic footwear is built on a model of patient's foot, for people with diabetes suffering with neuropathy. Can the footwear helps to improve plantar pressure in neuropathic foot? This study focussed on available data on therapeutic footwear as an intervention for improving and offloading plantar pressure in neuropathic diabetic foot.

METHODS

Relevant scientific literature in PubMed, Medline and Google Scholar published between 2000 and 2017 were searched. The keywords searched were therapeutic footwear, plantar pressure, neuropathic foot, rocker sole, ulcer healing and offloading of plantar pressure. Articles on randomized controlled trials, observational, cohort, feasibility and factorial studies were reviewed.

RESULTS

One hundred and twenty five (125) articles were identified. The article comprised of 6 randomized controlled trials, 2 observational, 1 cohort, 1 feasibility and 1 factorial study met the inclusion criteria and were critiqued with a total enrolment of 1380 study subjects.

CONCLUSIONS

The review of the collated literature demonstrated that, therapeutic footwear can improve the healing of neuropathic diabetic foot ulcer by redistributing plantar pressure. However, the efficacy of therapeutic footwear requires the inclusion of technical features that should not be compromised from the design to the production of the footwear.

Advantages of early diagnosis of diabetic neuropathy in the prevention of diabetic foot ulcers

AIMS

To evaluate the utility of the sudomotor function test (SFT) as a clinical tool in the Risk Stratification System of diabetic patients and to demonstrate the earlier detection of the risk of developing diabetic foot ulcers (DFU) compared to the standard clinical tests.

METHODS

Prospective follow-up study on 263 patients enrolled consecutively over 3.5 years. Diabetic patients without active DFU were classified according to the International Working Group Risk Stratification System (RSS) and categorized according to the results of the Semmes-Wenstein Monofilament (SWM) and biothesiometer measurements or the SFT. The main outcome evaluated was the development of DFU.

RESULTS

Median follow-up was 42 [38-44] months. Sixty patients (22.8%) developed DFU after a median of 6.2 [3-17] months. Ten patients that were included in the no-risk group (group 0) based on the SWM and biothesiometer results developed DFU. Thus the sensitivity of this approach was 83.33% and the specificity was 50.47%. Based on the SFT results, all patients that developed DFU were included in the correct risk group. This approach had 100% sensitivity and 31.53% specificity. Regarding the diagnostic accuracy of the two Methods, the respective AUC values were 0.776 (95% CI 0.702-0.849) and 0.816 (95% CI 0.757-0.874).

CONCLUSIONS

SFT improved RSS in diabetic patients in a specialized diabetic foot unit. SFT categorized patients correctly according to the risk of developing DFU.

The development and validation of a multivariable prognostic model to predict foot ulceration in diabetes using a systematic review and individual patient data meta-analyses

AIMS

Diabetes guidelines recommend screening for the risk of foot ulceration but vary substantially in the underlying evidence base. Our purpose was to derive and validate a prognostic model of independent risk factors for foot ulceration in diabetes using all available individual patient data from cohort studies conducted worldwide.

METHODS

We conducted a systematic review and meta-analysis of individual patient data from 10 cohort studies of risk factors in the prediction of foot ulceration in diabetes. Predictors were selected for plausibility, availability and low heterogeneity. Logistic regression produced adjusted odds ratios (ORs) for foot ulceration by ulceration history, monofilament insensitivity, any absent pedal pulse, age, sex and diabetes duration.

RESULTS

The 10 studies contained data from 16 385 participants. A history of foot ulceration produced the largest OR [6.59 (95% CI 2.49 to 17.45)], insensitivity to a 10 g monofilament [3.18 (95% CI 2.65 to 3.82)] and any absent pedal pulse [1.97 (95% CI 1.62 to 2.39)] were consistently, independently predictive. Combining three predictors produced sensitivities between 90.0% (95% CI 69.9% to 97.2%) and 95.3% (95% CI 84.5% to 98.7%); the corresponding specificities were between 12.1% (95% CI 8.2% to 17.3%) and 63.9% (95% CI 61.1% to 66.6%).

CONCLUSIONS

This prognostic model of only three risk factors, a history of foot ulceration, an inability to feel a 10 g monofilament and the absence of any pedal pulse, compares favourably with more complex approaches to foot risk assessment recommended in clinical diabetes guidelines.

RETRACTED: Extranodal natural killer/T-cell lymphoma masquerading a diabetic foot ulcer

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief due to an author reporting that they were listed without their permission.

Measuring Weight-Bearing Activities in Patients With Previous Diabetic Foot Ulcers

PURPOSE

The purpose of this article was to evaluate the accuracy of 2 physical activity monitors, monitors 1 and 2, for measuring weight-bearing activity in persons with prior diabetic foot ulcers.

DESIGN

Cross-sectional design.

INSTRUMENTS

Two recently developed monitors were used to differentiate anatomical postures such as lying, sitting, and standing upright. One monitor was designed to distinguish between duration of standing and walking and the other combines duration of standing and walking into 1 measure.

SUBJECTS AND SETTING

Thirty-one subjects were recruited; all participants had experienced a diabetic foot ulcer and completed participation in a previous cohort study. The study setting was 2 medical centers in the Midwestern United States.

METHODS

Subjects simultaneously wore the 2 monitors while performing 14 weight-bearing (ie, walking and standing) and non-weight-bearing (ie, sitting and lying) activities. The duration spent on each activity and the total number of steps taken for each walking activity were directly observed and recorded with each monitor. The accuracy of monitors 1 and 2 was assessed via direct observation as a reference standard. Paired-samples t tests were used to examine the difference in accuracy between the 2 monitors.

RESULTS

For measuring duration of activity, the accuracy of monitor 1 ranged from 73% to 100% for walking, 50% for standing, and from 42% to 100% for sitting/lying. In contrast, the accuracy of monitor 2 ranged from 98% to 100% for walking, 100% for standing, and from 97% to 100% for sitting/lying. The accuracy of monitor 1 for counting the number of steps ranged from 43% to 81%, while the accuracy of monitor 2 ranged from 91% to 99%. Monitor 2 was significantly more accurate than monitor 1 in measuring duration of standing still, slow walking, pedaling while sitting, lying on the left, and lying on the right, as well as measuring steps across different kinds of walking activities. Differences in monitor accuracy between subjects with and without foot pain and between subjects with and without foot amputation were not statistically significant.

CONCLUSION

These findings suggest that monitor 2 is a more accurate measure of weight-bearing activities than monitor 1 among patients with previous diabetic foot ulcers. Additionally, the 2 monitors differ in terms of function; monitor 2 distinguishes standing from walking, whereas monitor 1 combines standing and walking into 1 measure. We recommend monitor 2 to examine the impact of weight-bearing activity on foot ulceration in patients with diabetic neuropathy.

Severity and duration of diabetic foot ulcer (DFU) before seeking care as predictors of healing time: A retrospective cohort study

OBJECTIVES

To investigate whether A) duration of ulcer before start of treatment in specialist health care, and B) severity of ulcer according to University of Texas classification system (UT) at start of treatment (baseline), are independent predictors of healing time.

METHODS

This retrospective cohort study, based on electronic medical record data, included 105 patients from two outpatient clinics in Western Norway with a new diabetic foot ulcer during 2009-2011. The associations of duration of ulcer and ulcer severity with healing time were assessed using cumulative incidence curves and subdistribution hazard ratio estimated using competing risk regression with adjustment for potential confounders.

RESULTS

Of the 105 participants, 45.7% achieved ulcer healing, 36.2% underwent amputations, 9.5% died before ulcer healing and 8.5% were lost to follow-up. Patients who were referred to specialist health care by a general practitioner ≥ 52 days after ulcer onset had a 58% (SHR 0.42, CI 0.18-0.98) decreased healing rate compared to patients who were referred earlier, in the adjusted model. High severity (grade 2/3, stage C/D) according to the UT classification system was associated with a decreased healing rate compared to low severity (grade1, stage A/B or grade 2, stage A) with SHR (95% CI) equal to 0.14 (0.05-0.43) after adjustment for referral time and other potential confounders.

CONCLUSION

Early detection and referral by both the patient and general practitioner are crucial for optimal foot ulcer healing. Ulcer grade and severity are also important predictors for healing time, and early screening to assess the severity and initiation of prompt treatment is important.

Diabetic foot ulcer development risk classifications' validation: A multicentre prospective cohort study

AIMS

To prospectively validate the existing classifications to stratify subjects with diabetes mellitus (DM) by their risk of diabetic foot ulcer (DFU), in high and low risk settings.

METHODS

A prospective multicentre cohort study was conducted, including 446 subjects with DM without active DFU followed in the hospital or primary care setting. Demographic, clinical characterization variables, and those included in the classifications were collected at baseline. Subjects were followed for 1year, until DFU or death.

RESULTS

In our sample, with a mean age of 65years, 52% were male; 32 developed a DFU, 7 required an amputation and 18 died. Differences were found between participants' characteristics and classifications' accuracy according to the setting. The great majority of the variables were associated with higher DFU risk. Globally, classifications were highly and equally valid, positive predictive values (PV) were inferior to 40%, negative PV superior to 90% and area under the receiver operating characteristic curve superior to 0.75.

DISCUSSION

All the existing classifications are valid to be applied in high risk clinical context and have a very high capacity to categorize as low risk those subjects that will not develop a DFU. Further research is needed in the primary care setting.

Can plantar soft tissue mechanics enhance prognosis of diabetic foot ulcer?

AIM

To investigate if the assessment of the mechanical properties of plantar soft tissue can increase the accuracy of predicting Diabetic Foot Ulceration (DFU).

METHODS

40 patients with diabetic neuropathy and no DFU were recruited. Commonly assessed clinical parameters along with plantar soft tissue stiffness and thickness were measured at baseline using ultrasound elastography technique. 7 patients developed foot ulceration during a 12months follow-up. Logistic regression was used to identify parameters that contribute to predicting the DFU incidence. The effect of using parameters related to the mechanical behaviour of plantar soft tissue on the specificity, sensitivity, prediction strength and accuracy of the predicting models for DFU was assessed.

RESULTS

Patients with higher plantar soft tissue thickness and lower stiffness at the 1st Metatarsal head area showed an increased risk of DFU. Adding plantar soft tissue stiffness and thickness to the model improved its specificity (by 3%), sensitivity (by 14%), prediction accuracy (by 5%) and prognosis strength (by 1%). The model containing all predictors was able to effectively (χ² (8, N=40)=17.55, P<0.05) distinguish between the patients with and without DFU incidence.

CONCLUSION

The mechanical properties of plantar soft tissue can be used to improve the predictability of DFU in moderate/high risk patients.

Understanding Diabetic Foot Infection and its Management

Diabetic Foot Ulcers (DFUs), a dreadful micro-vascular complication is liable for substantial increase in morbidity and mortality. DFU is a complicated amalgam of neuropathy, peripheral arterial diseases, foot deformities and infection. Spanning the spectrum from superficial cellulitis, microbial flora leads to chronic ostemyelitis and gangrenous extremity lower limb amputations. Wounds without affirmation of soft tissue or bone infection do not require antibiotic therapy. Treatment of mild and moderate infection requires empiric therapy covering gram-positive cocci, whereas severe or infection caused by drug resistant organisms needs broad spectrum anti-microbial targeting aggressive gram-negative aerobes and obligate anaerobes. Definitive therapy employed should be based on culture reports and clinical response. Evaluation of bone infection requires imaging by plain radiographs or MRI to increase sensitivity and specificity. Surgical interventions are must and may range from minor debridement to resections or revascularization and major amputations depending upon wound severity. On time and forceful management of diabetic foot ulcers by employing multidisciplinary management approaches focusing on prevention, learning, regular foot assessment, aggressive intervention, and optimal use of therapeutic footwear can often prevent exacerbation of the difficulty and eliminate the potential for amputation. Here, we review recent studies addressing diabetic foot infections with emphasis on pathophysiology, exclusive risk factors; evaluation including physical inspection, laboratory investigations, relevant treatment strategies and assessment of infection severity.

The silent overall burden of foot disease in a representative hospitalised population

The aims of this study were to investigate the point prevalence, and associated independent factors, for foot disease (ulcers, infections and ischaemia) in a representative hospitalised population. We included 733 (83%) of 883 eligible adult inpatients across five representative Australian hospitals on one day. We collected an extensive range of self-reported characteristics from participants. We examined all participants to clinically diagnose foot disease (ulcers, infections and ischaemia) and amputation procedures. Overall, 72 participants (9·8%) [95% confidence interval (CI):7·2-11·3%] had foot disease. Foot ulcers, in 49 participants (6·7%), were independently associated with peripheral neuropathy, peripheral arterial disease, previous foot ulcers, trauma and past surgeon treatment (P < 0·05). Foot infections, in 24 (3·3%), were independently associated with previous foot ulcers, trauma and past surgeon treatment (P < 0·01). Ischaemia, in 33 (4·5%), was independently associated with older age, smokers and past surgeon treatment (P < 0·01). Amputation procedures, in 14 (1·9%), were independently associated with foot infections (P < 0·01). We found that one in every ten inpatients had foot disease, and less than half of those had diabetes. After adjusting for diabetes, factors linked with foot disease were similar to those identified in diabetes-related literature. The overall inpatient foot disease burden is similar in size to well-known medical conditions and should receive similar attention.

Neuropathy and Diabetic Foot Syndrome

Diabetic foot ulceration is a serious complication of diabetes mellitus worldwide and the most common cause of hospitalization in diabetic patients. The etiology of diabetic foot ulcerations is complex due to their multifactorial nature; in the pathophysiology of diabetic foot ulceration polyneuropathy is important. Proper adherence to standard treatment strategies and interdisciplinary cooperation can reduce the still high rates of major amputations.

A new diabetic foot risk assessment tool: DIAFORA

AIMS

This study aimed to derive a new model to classify subjects with diabetes and active diabetic foot ulcer by their risk of lower extremity amputation.

METHODS

A prospective cohort study was conducted that included all subjects with diabetic foot ulcer attending our Hospital Diabetic Foot Clinic from 2010 to 2013. Variables were collected at baseline. Subjects were followed up until healing, lower extremity amputation, death or for at least 3 months. Logistic regression was used to derive the new model, and the area under the receiver operating characteristic curve was assessed to propose the model with the greatest discrimination.

RESULTS

A total of 293 participants were included and followed for a median of 91 days. In 23.2% amputation was required, 5.1% died and 3.1% were lost. Our final model included the variables most commonly used in clinical practice for diabetic foot risk assessment (presence of neuropathy, foot deformity, peripheral arterial disease and previous foot complications) in addition to multiple diabetic foot ulcer, infection, gangrene and bone involvement. This model had an area under the receiver operating characteristic curve of 0.91 [95% confidence interval (CI) 0.87-0.95] and as classification of 0.89 (95% CI 0.84-0.93) for lower extremity amputation prediction. The high-risk group presented a positive likelihood ratio of 5 (95% CI 3-8) and predictive value of 58 (46-71). Only one minor lower extremity amputation occurred in the low-risk group.

CONCLUSIONS

We propose a new classification: diabetic foot risk assessment (DIAFORA). This classification was equally or more accurate for lower extremity amputation prediction in diabetic foot ulcer patients when compared with the existing ones.

A systematic review and individual patient data meta-analysis of prognostic factors for foot ulceration in people with diabetes: the international research collaboration for the prediction of diabetic foot ulcerations (PODUS)

BACKGROUND

Annual foot risk assessment of people with diabetes is recommended in national and international clinical guidelines. At present, these are consensus based and use only a proportion of the available evidence.

OBJECTIVES

We undertook a systematic review of individual patient data (IPD) to identify the most highly prognostic factors for foot ulceration (i.e. symptoms, signs, diagnostic tests) in people with diabetes.

DATA SOURCES

Studies were identified from searches of MEDLINE and EMBASE.

REVIEW METHODS

The electronic search strategies for MEDLINE and EMBASE databases created during an aggregate systematic review of predictive factors for foot ulceration in diabetes were updated and rerun to January 2013. One reviewer applied the IPD review eligibility criteria to the full-text articles of the studies identified in our literature search and also to all studies excluded from our aggregate systematic review to ensure that we did not miss eligible IPD. A second reviewer applied the eligibility criteria to a 10% random sample of the abstract search yield to check that no relevant material was missed. This review includes exposure variables (risk factors) only from individuals who were free of foot ulceration at the time of study entry and who had a diagnosis of diabetes mellitus (either type 1 or type 2). The outcome variable was incident ulceration.

RESULTS

Our search identified 16 cohort studies and we obtained anonymised IPD for 10. These data were collected from more than 16,000 people with diabetes worldwide and reanalysed by us. One data set was kept for independent validation. The data sets contributing IPD covered a range of temporal, geographical and clinical settings. We therefore selected random-effects meta-analysis, which assumes not that all the estimates from each study are estimates of the same underlying true value, but rather that the estimates belong to the same distribution. We selected candidate variables for meta-analysis using specific criteria. After univariate meta-analyses, the most clinically important predictors were identified by an international steering committee for inclusion in the primary, multivariable meta-analysis. Age, sex, duration of diabetes, monofilaments and pulses were considered most prognostically important. Meta-analyses based on data from the entire IPD population found that an inability to feel a 10-g monofilament [odds ratio (OR) 3.184, 95% confidence interval (CI) 2.654 to 3.82], at least one absent pedal pulse (OR 1.968, 95% CI 1.624 to 2.386), a longer duration of a diagnosis of diabetes (OR 1.024, 95% CI 1.011 to 1.036) and a previous history of ulceration (OR 6.589, 95% CI 2.488 to 17.45) were all predictive of risk. Female sex was protective (OR 0.743, 95% CI 0.598 to 0.922).

LIMITATIONS

It was not possible to perform a meta-analysis using a one-step approach because we were unable to procure copies of one of the data sets and instead accessed data via Safe Haven.

CONCLUSIONS

The findings from this review identify risk assessment procedures that can reliably inform national and international diabetes clinical guideline foot risk assessment procedures. The evidence from a large sample of patients in worldwide settings show that the use of a 10-g monofilament or one absent pedal pulse will identify those at moderate or intermediate risk of foot ulceration, and a history of foot ulcers or lower-extremity amputation is sufficient to identify those at high risk. We propose the development of a clinical prediction rule (CPR) from our existing model using the following predictor variables: insensitivity to a 10-g monofilament, absent pedal pulses and a history of ulceration or lower-extremities amputations. This CPR could replace the many tests, signs and symptoms that patients currently have measured using equipment that is either costly or difficult to use.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42011001841.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Clinico-microbiological study and antibiotic resistance profile of mecA and ESBL gene prevalence in patients with diabetic foot infections

Diabetic foot infections (DFIs) constitute a major complication of diabetes mellitus. DFIs contribute to the development of gangrene and non-traumatic lower extremity amputations with a lifetime risk of up to 25%. The aim of the present study was to identify the presence of neuropathy and determine the ulcer grade, microbial profile and phenotypic and genotypic prevalence of the methicillin-resistance gene mecA and extended spectrum β-lactamase (ESBL)-encoding genes in bacterial isolates of DFI in patients registered at the Pakistan Institute of Medical Sciences (Islamabad, Pakistan). The results indicated that 46/50 patients (92%), exhibited sensory neuropathy. The most common isolate was Staphylococcus aureus (25%), followed by Pseudomonas aeruginosa (P. aeruginosa; 18.18%), Escherichia coli (16.16%), Streptococcus species (spp.) (15.15%), Proteus spp. (15.15%), Enterococcus spp. (9%) and Klebsiella pneumoniae (K. pneumoniae; 3%). The prevalence of the mecA gene was found to be 88% phenotypically and 84% genotypically. K. pneumoniae was shown to have the highest percentage of ESBL producers with a prevalence of 66.7% by double disk synergy test, and 100% by the cefotaxime + clavulanic acid/ceftazidime + clavulanic acid combination disk test. P. aeruginosa and K. pneumoniae had the highest (100%) proportion of metallo β-lactamase producers as identified by the EDTA combination disk test. The overall prevalence of β-lactamase (bla)-CTX-M, bla-CTX-M-15, bla-TEM, bla-OXA and bla-SHV genes was found to be 76.9, 76.9, 75.0, 57.7 and 84.6%, respectively, in gram-negative DFI isolates. The prevalence of mecA and ESBL-related genes was found to be alarmingly high in DFIs, since these genes are a major cause of antibiotic treatment failure.

Identifying at-risk foot among hospitalized patients with type 2 diabetes: A cross-sectional study in one Chinese tertiary hospital

OBJECTIVE

To investigate the prevalence of diabetic at-risk foot and its associated factors.

METHODS

A total of 838 hospitalized patients with type 2 diabetes were screened for at-risk foot. Neural and vascular disorders were evaluated by assessing vibration perception thresholds and ankle brachial indexes (ABIs). After excluding 12 patients with abnormally high ABIs, remaining individuals with neural and/or vascular disorder were identified as at-risk patients and further classified into three subtypes: isolated neural disorder, isolated vascular disorder and mixed disorder. Potential associated factors were examined using Logistic regression models.

RESULTS

In the final sample of 826 individuals, the prevalence of diabetic at-risk foot was 30.6%. Among all at-risk patients, isolated neural disorders (69.6%) were more common than mixed (16.2%) or isolated vascular disorders (14.2%). Isolated neural and vascular disorders shared specific risk factors, including age per 20-year increment (odds ratio [95% CI], 3.73 [2.59-5.37] and 4.01 [1.98-8.11]), diabetic duration ≥10 years (1.69 [1.13-2.54] and 3.29 [1.49-7.24]) and systolic blood pressure ≥140 mmHg (1.96 [1.31-2.93] and 2.90 [1.38-6.10]) respectively. In addition, isolated neural disorders were associated with a heavy smoking history (95%CI 2.69 [1.15-6.31]), increased high-sensitivity C-reactive protein levels (95%CI 1.30 [1.04-1.62]) and mild obesity (95%CI 0.49 [0.20-1.24]). Isolated vascular disorders were linked with decreased high density lipoprotein (HDL) cholesterol levels (95%CI 3.42 [1.31-8.96]) and increased triglycerides levels (95%CI 2.74 [1.26-5.97]).

CONCLUSIONS

Diabetic at-risk foot is epidemic among hospitalized patients with type 2 diabetes. Aging, long-term diabetes, hypertension, smoking, inflammatory response and dyslipidemia may be associated with the prevalence of diabetic at-risk foot.

A shift in priority in diabetic foot care and research: 75% of foot ulcers are preventable

Diabetic foot ulceration poses a heavy burden on the patient and the healthcare system, but prevention thereof receives little attention. For every euro spent on ulcer prevention, ten are spent on ulcer healing, and for every randomized controlled trial conducted on prevention, ten are conducted on healing. In this article, we argue that a shift in priorities is needed. For the prevention of a first foot ulcer, we need more insight into the effect of interventions and practices already applied globally in many settings. This requires systematic recording of interventions and outcomes, and well-designed randomized controlled trials that include analysis of cost-effectiveness. After healing of a foot ulcer, the risk of recurrence is high. For the prevention of a recurrent foot ulcer, home monitoring of foot temperature, pressure-relieving therapeutic footwear, and certain surgical interventions prove to be effective. The median effect size found in a total of 23 studies on these interventions is large, over 60%, and further increases when patients are adherent to treatment. These interventions should be investigated for efficacy as a state-of-the-art integrated foot care approach, where attempts are made to assure treatment adherence. Effect sizes of 75-80% may be expected. If such state-of-the-art integrated foot care is implemented, the majority of problems with foot ulcer recurrence in diabetes can be resolved. It is therefore time to act and to set a new target in diabetic foot care. This target is to reduce foot ulcer incidence with at least 75%.

Prevention of foot ulcers in the at-risk patient with diabetes: a systematic review

BACKGROUND

Prevention of foot ulcers in patients with diabetes is extremely important to help reduce the enormous burden of foot ulceration on both patient and health resources. A comprehensive analysis of reported interventions is not currently available, but is needed to better inform caregivers about effective prevention. The aim of this systematic review is to investigate the effectiveness of interventions to prevent first and recurrent foot ulcers in persons with diabetes who are at risk for ulceration.

METHODS

The available medical scientific literature in PubMed, EMBASE, CINAHL and the Cochrane database was searched for original research studies on preventative interventions. Both controlled and non-controlled studies were selected. Data from controlled studies were assessed for methodological quality by two independent reviewers.

RESULTS

From the identified records, a total of 30 controlled studies (of which 19 RCTs) and another 44 non-controlled studies were assessed and described. Few controlled studies, of generally low to moderate quality, were identified on the prevention of a first foot ulcer. For the prevention of recurrent plantar foot ulcers, multiple RCTs with low risk of bias show the benefit for the use of daily foot skin temperature measurements and consequent preventative actions, as well as for therapeutic footwear that demonstrates to relieve plantar pressure and that is worn by the patient. To prevent recurrence, some evidence exists for integrated foot care when it includes a combination of professional foot treatment, therapeutic footwear and patient education; for just a single session of patient education, no evidence exists. Surgical interventions can be effective in selected patients, but the evidence base is small.

CONCLUSION

The evidence base to support the use of specific self-management and footwear interventions for the prevention of recurrent plantar foot ulcers is quite strong, but is small for the use of other, sometimes widely applied, interventions and is practically nonexistent for the prevention of a first foot ulcer and non-plantar foot ulcer.

Non-invasive method to analyse the risk of developing diabetic foot

Foot complications (diabetic foot) are among the most serious and costly complications of diabetes mellitus. Amputation of all or part of a lower extremity is usually preceded by a foot ulcer. To prevent diabetic foot, an automatic non-invasive method to identify patients with diabetes who have a high risk of developing diabetic foot is proposed. To design the proposed method, information concerning social scope and self-care of 153 diabetic patients was presented to the K-means clustering algorithm, which divided the data into two groups: high risk and low risk of developing diabetic foot. In the operational stage, the Euclidian distance from the information vector to the centroids of each group of risk is used as criterion for classification. Both real and simulated data were used to evaluate the method in which promising results were achieved with accuracy of 0.97 ± 0.06 for simulated data and 0.68 ± 0.16 considering the classification of specialists as the gold standard for real data. The method requires a simple computational processing and can be useful for basic health units to triage diabetic patients helping the health-care team to reduce the number of cases of diabetic foot.