title: Predictors of lower-extremity amputation in patients with an infected diabetic foot ulcer.
abstract: OBJECTIVE
  Infection commonly complicates diabetic foot ulcers and is associated with a poor outcome. In a cohort of individuals with an infected diabetic foot ulcer, we aimed to determine independent predictors of lower-extremity amputation and the predictive value for amputation of the International Working Group on the Diabetic Foot (IWGDF) classification system and to develop a risk score for predicting amputation.
  
  
  METHODS
  We prospectively studied 575 patients with an infected diabetic foot ulcer presenting to 1 of 14 diabetic foot clinics in 10 European countries.
  
  
  RESULTS
  Among these patients, 159 (28%) underwent an amputation. Independent risk factors for amputation were as follows: periwound edema, foul smell, (non)purulent exudate, deep ulcer, positive probe-to-bone test, pretibial edema, fever, and elevated C-reactive protein. Increasing IWGDF severity of infection also independently predicted amputation. We developed a risk score for any amputation and for amputations excluding the lesser toes (including the variables sex, pain on palpation, periwound edema, ulcer size, ulcer depth, and peripheral arterial disease) that predicted amputation better than the IWGDF system (area under the ROC curves 0.80, 0.78, and 0.67, respectively).
  
  
  CONCLUSIONS
  For individuals with an infected diabetic foot ulcer, we identified independent predictors of amputation, validated the prognostic value of the IWGDF classification system, and developed a new risk score for amputation that can be readily used in daily clinical practice. Our risk score may have better prognostic accuracy than the IWGDF system, the only currently available system, but our findings need to be validated in other cohorts.
authors: Division of Endocrinology, Department of Internal Medicine, Maastricht University Medical Centre, Maastricht, the Netherlands k.pickwell@mumc.nl.
authors: Kristy
authors: K
authors: Pickwell
authors: Research Unit for General Practice and Section of General Practice, Department of Public Health, University of Copenhagen, Copenhagen, Denmark.
authors: Volkert
authors: V
authors: Siersma
authors: Division of Endocrinology, Department of Internal Medicine, Maastricht University Medical Centre, Maastricht, the Netherlands.
authors: Marleen
authors: M
authors: Kars
authors: Department of Endocrinology, University of Malmö, Malmö, Sweden.
authors: Jan
authors: J
authors: Apelqvist
authors: International Diabetes Federation, Consultative Section and International Working Group on the Diabetic Foot, Heemstede, the Netherlands.
authors: Karel
authors: K
authors: Bakker
authors: Diabetic Department, Kings College Hospital, London, U.K.
authors: Michael
authors: M
authors: Edmonds
authors: Copenhagen Wound Healing Centre, Bispebjerg Hospital, Copenhagen, Denmark.
authors: Per
authors: P
authors: Holstein
authors: Diabetes Centre, Institute for Clinical and Experimental Medicine, Prague, Czech Republic.
authors: Alexandra
authors: A
authors: Jirkovská
authors: Diabetes Centre, Tameside General Hospital, Ashton-under-Lyne, U.K.
authors: Edward
authors: E
authors: Jude
authors: Department of Endocrinology and Nutrition, Hospital de Sant Pau, Autonomous University of Barcelona, Barcelona, Spain.
authors: Didac
authors: D
authors: Mauricio
authors: Sezione Dipartimentale Piede Diabetico, Dipartimento di Area Medica, Azienda Ospedaliero-Universitaria Pisana, Pisa, Italy.
authors: Alberto
authors: A
authors: Piaggesi
authors: Swedish Institute for Health Economics, Lund, Sweden.
authors: Gunnel
authors: G
authors: Ragnarson Tennvall
authors: Innere Abteilung, Mariannen Hospital, Werl, Germany.
authors: Heinrich
authors: H
authors: Reike
authors: Mathias-Spital, Diabetic Department, Rheine, Germany.
authors: Maximilian
authors: M
authors: Spraul
authors: Policlinico Tor Vergata, Department of Internal Medicine, Rome, Italy.
authors: Luigi
authors: L
authors: Uccioli
authors: Department of Endocrinology, University Medical Centre, Ljubljana, Slovenia.
authors: Vilma
authors: V
authors: Urbancic
authors: Department of Endocrinology, H Familie Ziekenhuis and Centre de Santé des Fagnes, Rumst and Chimay, Belgium.
authors: Kristien
authors: K
authors: van Acker
authors: Department of Surgery, Twenteborg Ziekenhuis, Almelo, the Netherlands.
authors: Jeff
authors: J
authors: van Baal
authors: Division of Endocrinology, Department of Internal Medicine, Maastricht University Medical Centre, Maastricht, the Netherlands.
authors: Nicolaas
authors: N
authors: Schaper
mesh_terms: D000368:Aged; D000671:Amputation, Surgical / Q000706:statistics & numerical data*; D002097:C-Reactive Protein / Q000378:metabolism; D017719:Diabetic Foot / Q000150:complications / Q000601:surgery*; D004487:Edema / Q000209:etiology; D005260:Female; D005334:Fever / Q000209:etiology; D006801:Humans; D007239:Infections / Q000150:complications* / Q000601:surgery; D008297:Male; D009812:Odorants; D058729:Peripheral Arterial Disease / Q000150:complications; D011379:Prognosis; D011446:Prospective Studies; D012307:Risk Factors
chemical_list: D002097:C-Reactive Protein