title: Provider volume and outcomes for abdominal aortic aneurysm repair, carotid endarterectomy, and lower extremity revascularization procedures.
abstract: BACKGROUND
  Intuitively, vascular procedures performed by high-volume vascular subspecialists working at high-volume institutions should be associated with improved patient outcome. Although a large number of studies assess the relationship between volume and outcome, a single contemporary compilation of such studies is lacking.
  
  
  METHODS
  A review of the English language literature was performed incorporating searches of the Medline, EMBASE, and Cochrane collaboration databases for abdominal aortic aneurysm repair (elective and emergent), carotid endarterectomy, and arterial lower limb procedures for any volume outcome relationship. Studies were included if they involved a patient cohort from 1980 onwards, were community or population based, and assessed health outcomes (mortality and morbidity) as a dependent variable and volume as an independent variable.
  
  
  RESULTS
  We identified 74 relevant studies, and 54 were included. All showed either an inverse relationship of variable magnitude between provider volume and mortality, or no volume-outcome effect. The reduction in the risk-adjusted mortality rate (RAMR) for high-volume providers was 3% to 11% for elective abdominal aortic aneurysm (AAA) repair, 2.5 to 5% for emergent AAA repair, 0.7% to 4.7% carotid endarterectomy, and 0.3% to 0.9% for lower limb arterial bypass procedures. Subspeciality training also conferred a considerable morbidity and mortality benefit for emergent AAA repair, carotid endarterectomy, and lower limb arterial procedures.
  
  
  CONCLUSIONS
  High-volume providers have significantly better outcomes for vascular procedures both in the elective and emergent setting. Subspeciality training also has a considerable impact. These data provide further evidence for the specialization of vascular services, whereby vascular procedures should generally be preformed by high-volume, speciality trained providers.
authors.affiliation: Department of Academic Surgery, National University of Ireland (NUI)/University College Cork (UCC), Cork University Hospital, Cork, Ireland. sdfkilleen@eircom.net
authors.forename: Shane D
authors.initials: SD
authors.lastname: Killeen
authors.forename: Emmet J
authors.initials: EJ
authors.lastname: Andrews
authors.forename: Henry P
authors.initials: HP
authors.lastname: Redmond
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Fulton
mesh_terms: D017544:Aortic Aneurysm, Abdominal / Q000401:mortality / Q000601:surgery*; D002340:Carotid Artery Diseases / Q000401:mortality / Q000601:surgery*; D002568:Certification; D004503:Education, Medical, Graduate; D017558:Elective Surgical Procedures / Q000706:statistics & numerical data; D004632:Emergency Medical Services / Q000706:statistics & numerical data; D016894:Endarterectomy, Carotid / Q000706:statistics & numerical data; D006276:Health Facility Size; D017052:Hospital Mortality / Q000639:trends; D006761:Hospitals / Q000706:statistics & numerical data*; D006801:Humans; D035002:Lower Extremity / Q000098:blood supply; D016491:Peripheral Vascular Diseases / Q000401:mortality / Q000601:surgery*; D018570:Risk Assessment; D013043:Specialties, Surgical / Q000193:education / Q000706:statistics & numerical data*; D016019:Survival Analysis; D016896:Treatment Outcome; D014656:Vascular Surgical Procedures / Q000193:education / Q000706:statistics & numerical data*; D016526:Workload / Q000706:statistics & numerical data*