title: The independent contribution of diabetic foot ulcer on lower extremity amputation and mortality risk.
abstract: OBJECTIVE
  To estimate 3-year risk for diabetic foot ulcer (DFU), lower extremity amputation (LEA) and death; determine predictive variables and assess derived models accuracy.
  
  
  METHODS
  Retrospective cohort study including all subjects with diabetes enrolled in our diabetic foot outpatient clinic from beginning 2002 until middle 2010. Data were collected from clinical records.
  
  
  RESULTS
  644 subjects with mean age of 65.1 (±11.2) and diabetes duration of 16.1 (±10.8) years. Cumulative incidence was 26.6% for DFU, 5.8% for LEA and 14.0% for death. In multivariate analysis, physical impairment, peripheral arterial disease complication history, complication count and previous DFU were associated with DFU; complication count, foot pulses and previous DFU with LEA and age, complication count and previous DFU with death. Predictive models' areas under the ROC curves ranged from 0.80 to 0.83. A simplified model including previous DFU and complication count presented high accuracy. Previous DFU was associated with all outcomes, even when adjusted for complication count, in addition to more complex models.
  
  
  CONCLUSIONS
  DFU seems more than a marker of complication status, having independent impact on LEA and mortality risk. Proposed models may be applicable in healthcare settings to identify patients at higher risk of DFU, LEA and death.
authors.affiliation: Diabetic Foot Clinic, Endocrinology, Diabetes and Metabolism Department - Centro Hospitalar de Vila Nova de Gaia/Espinho EPE, Vila Nova de Gaia, Portugal; Internal Medicine Department - Centro Hospitalar de Vila Nova de Gaia/Espinho EPE, Vila Nova de Gaia, Portugal; Biochemistry Department (U38-FCT)-Faculty of Medicine of the University of Porto, Oporto, Portugal. Electronic address: daniela.m.m.mendes@gmail.com.
authors.forename: Daniela
authors.initials: D
authors.lastname: Martins-Mendes
authors.affiliation: CIDES/CINTESIS (U753-FCT)-Health Information and Decision Sciences Department, Oporto Faculty of Medicine, Oporto, Portugal.
authors.forename: Matilde
authors.initials: M
authors.lastname: Monteiro-Soares
authors.affiliation: Seattle Epidemiologic Research and Information Centre-Department of Veterans Affairs Puget Sound Health Care System and the University of Washington, Seattle, WA, USA.
authors.forename: Edward John
authors.initials: EJ
authors.lastname: Boyko
authors.affiliation: Diabetic Foot Clinic, Endocrinology, Diabetes and Metabolism Department - Centro Hospitalar de Vila Nova de Gaia/Espinho EPE, Vila Nova de Gaia, Portugal.
authors.forename: Manuela
authors.initials: M
authors.lastname: Ribeiro
authors.affiliation: Health Sciences Faculty of the Fernando Pessoa's University, Oporto, Portugal.
authors.forename: Pedro
authors.initials: P
authors.lastname: Barata
authors.affiliation: Cancer Biology Group-Institute of Molecular Pathology and Immunology of the University of Porto, Oporto, Portugal, Faculty of Medicine of the University of Porto, Oporto, Portugal.
authors.forename: Jorge
authors.initials: J
authors.lastname: Lima
authors.affiliation: Biochemistry Department (U38-FCT)-Faculty of Medicine of the University of Porto, Oporto, Portugal.
authors.forename: Raquel
authors.initials: R
authors.lastname: Soares
mesh_terms: D000368:Aged; D000671:Amputation, Surgical / Q000401:mortality / Q000706:statistics & numerical data*; D002423:Cause of Death; D048909:Diabetes Complications / Q000401:mortality; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000401:mortality* / Q000601:surgery*; D017719:Diabetic Foot / Q000453:epidemiology* / Q000601:surgery*; D005260:Female; D006801:Humans; D035002:Lower Extremity / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012306:Risk; D012959:Socioeconomic Factors
keywords: Diabetes; Diabetic Foot; Foot ulcer; Mortality; Prediction