The Society for Vascular Surgery Wound, Ischemia, and foot Infection (WIfI) classification independently predicts wound healing in diabetic foot ulcers

Caitlin W Hicks; Joseph K Canner; Nestoras Mathioudakis; Ronald Sherman; Mahmoud B Malas; James H Black 3rd; Christopher J Abularrage

doi:10.1016/j.jvs.2017.12.079

The Society for Vascular Surgery Wound, Ischemia, and foot Infection (WIfI) classification independently predicts wound healing in diabetic foot ulcers

J Vasc Surg. 2018 Oct;68(4):1096-1103. doi: 10.1016/j.jvs.2017.12.079. Epub 2018 Apr 3.

Authors

Caitlin W Hicks¹, Joseph K Canner², Nestoras Mathioudakis³, Ronald Sherman¹, Mahmoud B Malas⁴, James H Black 3rd⁵, Christopher J Abularrage⁶

Affiliations

¹ Diabetic Foot and Wound Service, The Johns Hopkins Hospital, Baltimore, Md; Division of Vascular Surgery and Endovascular Therapy, Department of Surgery, The Johns Hopkins Hospital, Baltimore, Md.
² Center for Surgical Trials and Outcomes Research, Department of Surgery, The Johns Hopkins Hospital, Baltimore, Md.
³ Diabetic Foot and Wound Service, The Johns Hopkins Hospital, Baltimore, Md; Division of Endocrinology and Metabolism, Department of Medicine, The Johns Hopkins Hospital, Baltimore, Md.
⁴ Center for Surgical Trials and Outcomes Research, Department of Surgery, The Johns Hopkins Hospital, Baltimore, Md; Division of Endocrinology and Metabolism, Department of Medicine, The Johns Hopkins Hospital, Baltimore, Md.
⁵ Division of Vascular Surgery and Endovascular Therapy, Department of Surgery, The Johns Hopkins Hospital, Baltimore, Md.
⁶ Diabetic Foot and Wound Service, The Johns Hopkins Hospital, Baltimore, Md; Division of Vascular Surgery and Endovascular Therapy, Department of Surgery, The Johns Hopkins Hospital, Baltimore, Md. Electronic address: cabular1@jhmi.edu.

PMID: 29622357
DOI: 10.1016/j.jvs.2017.12.079

Abstract

Objective: Previous studies have reported correlation between the Wound, Ischemia, and foot Infection (WIfI) classification system and wound healing time on unadjusted analyses. However, in the only multivariable analysis to date, WIfI stage was not predictive of wound healing. Our aim was to examine the association between WIfI classification and wound healing after risk adjustment in patients with diabetic foot ulcers (DFUs) treated in a multidisciplinary setting.

Methods: All patients presenting to our multidisciplinary DFU clinic from June 2012 to July 2017 were enrolled in a prospective database. A Cox proportional hazards model accounting for patients' sociodemographics, comorbidities, medication profiles, and wound characteristics was used to assess the association between WIfI classification and likelihood of wound healing at 1 year.

Results: There were 310 DFU patients enrolled (mean age, 59.0 ± 0.7 years; 60.3% male; 60.0% black) with 709 wounds, including 32.4% WIfI stage 1, 19.9% stage 2, 25.2% stage 3, and 22.4% stage 4. Mean wound healing time increased with increasing WIfI stage (stage 1, 96.9 ± 8.3 days; stage 4, 195.1 ± 10.6 days; P < .001). Likelihood of wound healing at 1 year was 94.1% ± 2.0% for stage 1 wounds vs 67.4% ± 4.4% for stage 4 (P < .001). After risk adjustment, increasing WIfI stage was independently associated with poor wound healing (stage 4 vs stage 1: hazard ratio, [HR] 0.44; 95% confidence interval, 0.33-0.59). Peripheral artery disease (HR, 0.73), increasing wound area (HR, 0.99 per square centimeter), and longer time from wound onset to first assessment (HR, 0.97 per month) also decreased the likelihood of wound healing, whereas use of clopidogrel was protective (HR, 1.39; all, P ≤ .04). The top three predictors of poor wound healing were WIfI stage 4 (z score, -5.40), increasing wound area (z score, -3.14), and WIfI stage 3 (z score, -3.11), respectively.

Conclusions: Among patients with DFU, the WIfI classification system predicts wound healing at 1 year in both crude and risk-adjusted analyses. This is the first study to validate the WIfI score as an independent predictor of wound healing using multivariable analysis.

Keywords: DFU; Diabetic foot ulcer; Multidisciplinary care; WIfI.

MeSH terms

Combined Modality Therapy
Databases, Factual
Decision Support Techniques*
Diabetic Foot / classification
Diabetic Foot / diagnosis*
Diabetic Foot / pathology
Diabetic Foot / therapy*
Female
Humans
Male
Middle Aged
Multivariate Analysis
Predictive Value of Tests
Proportional Hazards Models
Retrospective Studies
Risk Factors
Severity of Illness Index
Time Factors
Treatment Outcome
Wound Healing*