title: Potential value of regionalized intensive care for mechanically ventilated medical patients.
abstract: BACKGROUND
  Regionalization has been proposed as a method to improve outcomes for medical patients receiving mechanical ventilation in the intensive care unit.
  
  
  OBJECTIVE
  To determine the number of patients who would be affected by regionalization and the potential mortality reduction under a regionalized system of care.
  
  
  METHODS
  We performed a retrospective cohort study with Monte Carlo simulation, using 2001 state discharge data from eight states representing 42% of the U.S. population. Adult medical patients undergoing invasive mechanical ventilation were identified. Patient location and hospital mortality rates were obtained from the discharge data; estimates of the relative risk reduction in hospital mortality for high-volume hospitals compared with low-volume hospitals were obtained from the published literature and applied to the cohort.
  
  
  RESULTS
  Of 180,976 adult medical patients who underwent mechanical ventilation at 1,170 nonfederal hospitals, 83,050 (46%) received mechanical ventilation at 887 (76%) hospitals with low annual volumes (fewer than 275 patients per year). Using published risk estimates, approximately 4,720 lives per year (95% range, 2,522-6,744) could potentially be saved in the 8 states by routinely transferring patients from low- to high-volume hospitals, representing a number needed to treat of 15.7. The median distance that patients would need to travel to reach a high-volume hospital was 8.5 miles (interquartile range, 4.0-21.2 mi).
  
  
  CONCLUSIONS
  Regionalization of intensive care could potentially improve survival for patients undergoing mechanical ventilation. Transfer distances are modest for most patients.
authors.affiliation: Division of Pulmonary, Allergy, and Critical Care, University of Pennsylvania School of Medicine, 723 Blockley Hall, 423 Guardian Drive, Philadelphia, PA 19104, USA. jmkahn@mail.med.upenn.edu
authors.forename: Jeremy M
authors.initials: JM
authors.lastname: Kahn
authors.forename: Walter T
authors.initials: WT
authors.lastname: Linde-Zwirble
authors.forename: Hannah
authors.initials: H
authors.lastname: Wunsch
authors.forename: Amber E
authors.initials: AE
authors.lastname: Barnato
authors.forename: Theodore J
authors.initials: TJ
authors.lastname: Iwashyna
authors.forename: Mark S
authors.initials: MS
authors.lastname: Roberts
authors.forename: Judith R
authors.initials: JR
authors.lastname: Lave
authors.forename: Derek C
authors.initials: DC
authors.lastname: Angus
mesh_terms: D015331:Cohort Studies; D003422:Critical Care; D017052:Hospital Mortality; D006761:Hospitals / Q000706:statistics & numerical data*; D006801:Humans; D007362:Intensive Care Units / Q000458:organization & administration*; D009010:Monte Carlo Method; D010360:Patient Transfer; D012017:Referral and Consultation; D012040:Regional Health Planning / Q000706:statistics & numerical data; D012121:Respiration, Artificial / Q000401:mortality / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D014481:United States