title: Improving outcomes for diabetic patients undergoing revascularization for critical limb ischemia: does the quality of outpatient diabetic care matter?
abstract: BACKGROUND
  Diabetic patients who undergo lower extremity surgical revascularization for critical limb ischemia (CLI) are at high risk for amputation or death, even when their inpatient procedures are successful. We hypothesized that postoperative outcomes might be improved in regions where diabetics with CLI receive more frequent high-quality outpatient care.
  
  
  METHODS
  A retrospective cohort study was performed among 172,134 patients with CLI (52% male, 15% black, mean age 76 years) who underwent open and endovascular lower extremity revascularization procedures using Medicare claims (2004-2007), which included 84,653 (49%) beneficiaries who were diabetic. Regional utilization of annual serum cholesterol and hemoglobin A1c testing were used to assess the quality of outpatient diabetic care. We examined relationships between frequency of diabetic testing with amputation-free survival (AFS), major adverse limb events (MALE), and rates of readmission across all US hospital referral regions.
  
  
  RESULTS
  There was significant regional variation in annual serum cholesterol and hemoglobin A1c testing across the United States (87% highest quartile vs. 59% lowest quartile, P < 0.01). Compared with the lowest quartile of diabetic testing, diabetic patients undergoing lower extremity revascularization in regions with the highest quartile of diabetic testing had significantly improved AFS (hazards ratio [HR]: 0.94, 95% confidence interval [CI]: 0.90-0.97; P < 0.01) and MALE (HR: 0.92, 95% CI: 0.89-0.96; P < 0.01) persisting up to 2 years after lower extremity revascularization, even after adjusting for procedure type, gender, age, race, and comorbidities. Moreover, the risk of 30-day readmission was significantly reduced in regions with the highest versus lowest quartile of diabetic testing (odds ratio: 0.91, 95% CI: 0.85-0.97; P < 0.01). Nondiabetic patients with CLI, in comparison, did not benefit to the same extent from undergoing revascularization in regions with high-quality outpatient diabetic care.
  
  
  CONCLUSIONS
  Diabetic patients undergoing lower extremity revascularization in regions with higher utilization of diabetic care quality measures have significantly better long-term limb salvage and readmission outcomes. Our study underscores the importance of providing optimal outpatient care to diabetics following vascular surgery and outlines a potential strategy for quality improvement in these high-risk patients.
authors.affiliation: Division of Vascular Surgery, University of Utah School of Medicine, Salt Lake City, UT. Electronic address: Benjamin.Brooke@hsc.utah.edu.
authors.forename: Benjamin S
authors.initials: BS
authors.lastname: Brooke
authors.affiliation: Division of Vascular Surgery, University of Utah School of Medicine, Salt Lake City, UT.
authors.forename: Larry W
authors.initials: LW
authors.lastname: Kraiss
authors.affiliation: Section of Vascular Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, NH.
authors.forename: David H
authors.initials: DH
authors.lastname: Stone
authors.affiliation: Section of Vascular Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, NH; Dartmouth Institute for Health Policy & Clinical Practice, Lebanon, NH.
authors.forename: Brian
authors.initials: B
authors.lastname: Nolan
authors.affiliation: Division of Vascular and Endovascular Surgery, Mayo Clinic, Rochester, MN.
authors.forename: Randall R
authors.initials: RR
authors.lastname: De Martino
authors.affiliation: Department of Health Services & Epidemiology, University of Washington, Seattle, WA.
authors.forename: Gayle E
authors.initials: GE
authors.lastname: Reiber
authors.affiliation: Dartmouth Institute for Health Policy & Clinical Practice, Lebanon, NH.
authors.forename: David C
authors.initials: DC
authors.lastname: Goodman
authors.affiliation: Section of Vascular Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, NH.
authors.forename: Jack L
authors.initials: JL
authors.lastname: Cronenwett
authors.affiliation: Section of Vascular Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, NH; Dartmouth Institute for Health Policy & Clinical Practice, Lebanon, NH.
authors.forename: Philip P
authors.initials: PP
authors.lastname: Goodney
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D002784:Cholesterol / Q000097:blood; D015897:Comorbidity; D003925:Diabetic Angiopathies / Q000601:surgery*; D057510:Endovascular Procedures; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007511:Ischemia / Q000601:surgery*; D023821:Limb Salvage; D035002:Lower Extremity / Q000098:blood supply*; D008297:Male; D010359:Patient Readmission / Q000706:statistics & numerical data; D019984:Quality Indicators, Health Care; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome; D014481:United States
chemical_list: D015415:Biomarkers; D002784:Cholesterol; D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human