Prognostic Models for Mortality in Patients with Diabetic Foot Ulcers: A Systematic Review

Abstract

Objective:

This study aims to systematically review and summarize existing prognostic models for all-cause mortality in patients with diabetic foot ulcers (DFUs). It further evaluates their characteristics, performance, and methodological quality to inform future model development and clinical application.

Approach:

We searched eight databases from their inception to February 24, 2025. Extracted data included general study characteristics and model-specific information. The prognostic models were classified using the transparent reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis guidelines and evaluated using the Prediction Model Risk of Bias Assessment Tool (PROBAST) to assess the risk of bias (ROB) and applicability.

Results:

Of the 1,580 retrieved studies, 19 were included, reporting a total of 22 prognostic models. Reported mortality rates among DFU patients ranged from 4.2% to 48.5%, with follow-up durations varying from 12 weeks to 22 years. All studies exhibited a high ROB due to issues with data sources, small sample sizes, inadequate data handling, and model validation flaws. Across the included prognostic models, the most frequently reported predictors were age, cardiovascular disease, renal disease, ulcer severity, ischemia, and serum albumin.

Innovation:

Prognostic assessment of mortality risk in patients with DFUs is critical for effective clinical management. This study systematically evaluated 22 published prognostic models using the PROBAST, identifying key methodological limitations and commonly used predictors. The findings provide a scientific basis for the future development of higher quality, clinically applicable prognostic models. In addition, this work offers valuable insights to inform clinical risk stratification and decision-making for DFU patients.

Conclusions:

All included prognostic models demonstrated a high ROB according to the PROBAST assessment. Future research should focus on using larger sample sizes, rigorous study designs, and multicenter external validation to develop more reliable prognostic models. Given the multifactorial nature of mortality risk in DFU patients, multidisciplinary collaboration is essential to improve clinical outcomes.