Citation: Nit , ˘ a, O.; Arhire, L.I.; Mihalache, L.; Popa, A.D.; Nit , ˘ a, G.; Gherasim, A.; Graur, M. Evaluating Classification Systems of Diabetic Foot Ulcer Severity: A 12-Year Retrospective Study on Factors Impacting Survival. Healthcare 2023, 11, 2077. https://doi.org/10.3390/ healthcare11142077 Academic Editor: Ioannis Ilias Received: 18 June 2023 Revised: 19 July 2023 Accepted: 19 July 2023 Published: 20 July 2023 Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). healthcare Article Evaluating Classification Systems of Diabetic Foot Ulcer Severity: A 12-Year Retrospective Study on Factors Impacting Survival Otilia Nit , ă 1 , Lidia Iuliana Arhire 1 , Laura Mihalache 1, * , Alina Delia Popa 1, * , George Nit , ă 1 , Andreea Gherasim 1 and Mariana Graur 2 1 Faculty of Medicine, University of Medicine and Pharmacy “Grigore T Popa”, 700115 Iasi, Romania; otilia.nita@umfiasi.ro (O.N.); lidia.graur@umfiasi.ro (L.I.A.); andreea.gherasim@umfiasi.ro (G.N.); george.nita@umfiasi.ro (A.G.) 2 Faculty of Medicine and Biological Sciences, University “S , tefan cel Mare” of Suceava, 720229 Suceava, Romania; graur.mariana@gmail.com * Correspondence: laura.mihalache@umfiasi.ro (L.M.); alina.popa@umfiasi.ro (A.D.P.) Abstract: (1) Background: This study examines the survival of patients after their first presentation with diabetic foot ulcers (DFUs) to the regional Diabetes, Nutrition, and Metabolic Diseases Clinic within the Emergency Clinical Hospital “Sf. Spiridon”, Ia¸ si, and analyzes the factors associated with this outcome. (2) Methods: In this retrospective study, patients with DFUs consecutively referred between 1 January 2007 and 31 December 2017 were followed up until 31 December 2020 (for 13 years). The study group included 659 subjects. (3) Results: During the study period, there were 278 deaths (42.2%) and the average survival time was 9 years. The length of hospitalization, diabetic nephropathy, chronic kidney disease, glomerular filtration rate, cardiovascular disease, hypertension, anemia, and DFU severity were the most significant contributors to the increase in mortality. Patients with severe ulcers, meaning DFUs involving the tendon, joint, or bone, had a higher mortality risk than those with superficial or pre-ulcerative lesions on initial presentation (Texas classification HR = 1.963, 95% CI: 1.063–3.617; Wagner–Meggitt classification HR = 1.889, 95% CI: 1.024–3.417, SINBAD Classification System and Score HR = 2.333, 95% CI: 1.258–4.326) after adjusting for confounding factors. (4) Conclusions: The findings of this study suggested that patients presenting with severe ulcers involving the tendon, joint, or bone exhibited a significantly higher risk of mortality, even when potential confounders were taken into consideration. Keywords: diabetic foot ulcers; survival; University of Texas Staging System; Wagner–Meggitt classification; SINBAD classification system and score; mortality 1. Introduction The prevalence of diabetes is increasing worldwide; therefore, one of the main goals of the World Health Organization (WHO) is fighting against this disease due to the impressive data related to diabetic foot epidemiology. Diabetes is the primary cause of 50 to 70% of all lower-limb amputations; 15% of diabetic patients will acquire a foot ulcer and 25–50% of them will need an amputation as a result of complications [1]. One amputation is performed every thirty seconds on a person with diabetes somewhere in the world, according to estimates [2]. Diabetic foot disease is a complex, specific complication in which neuropathy, peripheral artery disease, immunopathy, and infection [1,2] have the potential to injure all anatomical components of the lower limb: skin, nails, adipose tissue, muscles, fascia, vessels, nerves, bones, and joints [3,4]. Poor glycemic control, cigarette smoking, impaired vision, peripheral neuropathy with loss of protective sensation, peripheral artery disease, foot deformations, previous foot ulcers, and history of amputation are the most significant risk factors for diabetic foot ulcers (DFUs) [5,6]. Healthcare 2023, 11, 2077. https://doi.org/10.3390/healthcare11142077 https://www.mdpi.com/journal/healthcare