title: Trends and determinants of costs associated with the inpatient care of diabetic foot ulcers.
abstract: OBJECTIVE
  The cost of care for diabetic foot ulcers is estimated to be more than $1.5 billion annually. The aim of this study was to analyze inpatient diabetic foot ulcer cost changes over time and to identify factors associated with these costs.
  
  
  METHODS
  The Nationwide Inpatient Sample (2005-2010) was queried using the International Classification of Diseases, Ninth Revision codes for a primary diagnosis of foot ulceration. The primary outcomes were changes in adjusted total hospital charges and costs over time. Multivariable analysis was performed to assess relative increases (RIs) in hospital charges per patient in 2005 vs 2010 adjusting for demographic characteristics, income, comorbidities (Charlson Comorbidity Index ≥3), insurance type, hospital characteristics, diagnostic imaging, revascularization, amputation, and length of stay.
  
  
  RESULTS
  Overall, 336,641 patients were admitted with a primary diagnosis of diabetic foot ulceration (mean age, 62.9 ± 0.1 years, 59% male, 61% white race). The annual cumulative cost for inpatient treatment of diabetic foot ulcers increased significantly from 2005 to 2010 ($578,364,261 vs $790,017,704; P < .001). More patients were hospitalized (128.6 vs 152.8 per 100,000 hospitalizations; P < .001), and the mean adjusted cost per patient hospitalization increased significantly over time ($11,483 vs $13,258; P < .001). The proportion of nonelective admissions remained stable (25% vs 23%; P = .32) and there were no differences in mean hospital length of stay (7.0 ± 0.1 days vs 6.8 ± 0.1 days; P = .22). Minor (17.9% vs 20.6%; P < .001), but not major amputations (3.9% vs 4.2%; P = .27) increased over time. Based on multivariable analysis, the main factors contributing to the escalating cost per patient hospitalization included increased patient comorbidities (unadjusted mean difference 2005 vs 2010 $3303 [RI, 1.08] vs adjusted $15,220 [RI, 1.35]), open revascularization (unadjusted $15,145 [RI, 1.25] vs adjusted $30,759 [RI, 1.37]), endovascular revascularization (unadjusted $17,662 [RI, 1.29] vs adjusted $28.937 [RI, 1.38]), and minor amputations (unadjusted $9918 [RI, 1.24] vs adjusted $18,084 [RI, 1.33]) (P < .001, all).
  
  
  CONCLUSIONS
  Hospital charges and costs related to diabetic foot ulcers have increased significantly over time despite stable hospital length of stay and proportion of emergency admissions. Risk-adjusted analyses suggest that this change might be reflective of increasing charges associated with a progressively sicker patient population and attempts at limb salvage. Despite this, the overall incidence of major amputations remained stable.
authors.affiliation: Division of Vascular Surgery and Endovascular Therapy, Department of Surgery, The Johns Hopkins Hospital, Baltimore, Md.
authors.forename: Caitlin W
authors.initials: CW
authors.lastname: Hicks
authors.affiliation: Center for Surgical Trials and Outcomes Research, Department of Surgery, The Johns Hopkins Hospital, Baltimore, Md.
authors.forename: Shalini
authors.initials: S
authors.lastname: Selvarajah
authors.affiliation: Division of Endocrinology and Metabolism, Department of Medicine, The Johns Hopkins Hospital, Baltimore, Md; Diabetic Foot and Wound Service, The Johns Hopkins Hospital, Baltimore, Md.
authors.forename: Nestoras
authors.initials: N
authors.lastname: Mathioudakis
authors.affiliation: Division of Vascular Surgery and Endovascular Therapy, Department of Surgery, The Johns Hopkins Hospital, Baltimore, Md.
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Perler
authors.affiliation: Division of Vascular Surgery and Endovascular Therapy, Department of Surgery, The Johns Hopkins Hospital, Baltimore, Md.
authors.forename: Julie A
authors.initials: JA
authors.lastname: Freischlag
authors.affiliation: Division of Vascular Surgery and Endovascular Therapy, Department of Surgery, The Johns Hopkins Hospital, Baltimore, Md.
authors.forename: James H
authors.initials: JH
authors.lastname: Black
authors.affiliation: Division of Vascular Surgery and Endovascular Therapy, Department of Surgery, The Johns Hopkins Hospital, Baltimore, Md; Center for Surgical Trials and Outcomes Research, Department of Surgery, The Johns Hopkins Hospital, Baltimore, Md; Diabetic Foot and Wound Service, The Johns Hopkins Hospital, Baltimore, Md. Electronic address: cabular1@jhmi.edu.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Abularrage
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000671:Amputation, Surgical / Q000191:economics / Q000639:trends; D016009:Chi-Square Distribution; D015897:Comorbidity; D017719:Diabetic Foot / Q000175:diagnosis / Q000191:economics* / Q000628:therapy*; D004630:Emergencies; D004636:Emergency Service, Hospital / Q000191:economics / Q000639:trends; D057510:Endovascular Procedures / Q000191:economics / Q000639:trends; D005260:Female; D017721:Hospital Costs / Q000639:trends*; D006801:Humans; D007297:Inpatients; D007902:Length of Stay / Q000191:economics; D023821:Limb Salvage / Q000191:economics / Q000639:trends; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010343:Patient Admission / Q000191:economics* / Q000639:trends*; D010818:Practice Patterns, Physicians' / Q000191:economics / Q000639:trends; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States; D014656:Vascular Surgical Procedures / Q000191:economics* / Q000639:trends*; D055815:Young Adult