title: Interhospital transfer for intact abdominal aortic aneurysm repair.
abstract: OBJECTIVE
  Medically complex patients who need abdominal aortic aneurysm (AAA) repair are at increased risk of mortality. We study the effects of interhospital transfer to high-volume hospitals (HVHs) on postoperative complications and mortality after complications in these patients.
  
  
  METHODS
  Data for 491,779 patients undergoing intact AAA surgery were extracted using Medicare files. Patient demographics, comorbidities, hospital volume, repair type, and patient transfer status were collected. Primary outcomes were postoperative complications and failure to rescue within 30 days after surgery. Data were analyzed using multivariable and propensity analysis.
  
  
  RESULTS
  From 2000 to 2011, the percentage of patients transferred to another hospital for surgery before starting treatment more than doubled from .7% to 1.9% for endovascular aneurysm repair (EVAR; P < .001) and from 1.2% to 3.7% for open repair (P < .001). At baseline, transferred patients had more congestive heart failure (18.7% vs 11.2%; P < .001), coronary (17.4% vs 15.0%; P < .001), pulmonary (38.3% vs 33.6%; P < .001), and renal failure (8.1% vs 4.6%; P < .001) comorbidities. Transferred patients incurred more complications after EVAR (25.1% vs 12.8%; P < .001) or open repair (42.3% vs 35.5%; P < .001). After propensity matching for comorbidities and demographics, there were fewer complication rates (40.4% vs 47.8%; P < .001) and decreased failure to rescue (5.5% vs 6.5%; P = .04) after open repair in patients transferred to HVHs than in patients who remained at the primary, low-volume hospital for surgery. Complication rates after EVAR for nontransferred patients at low-volume hospitals and transferred patients at HVHs were similar (23.9% vs 24.7%; P = .55). After propensity matching, there was no significant difference in failure to rescue (P = .06) after EVAR between patients transferred to HVHs and nontransferred patients who had procedures at low-volume hospitals.
  
  
  CONCLUSIONS
  Transfer of medically complex patients to HVHs for open AAA repair improves outcomes in AAA surgery. Complication rates decrease, and survival of transferred patients increases when they undergo open repair at HVHs.
authors.affiliation: Mount Sinai St. Luke's-Roosevelt, New York, NY.
authors.forename: Nicole
authors.initials: N
authors.lastname: Ilonzo
authors.affiliation: Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai, New York, NY. Electronic address: natalia.egorova@mountsinai.org.
authors.forename: Natalia N
authors.initials: NN
authors.lastname: Egorova
authors.affiliation: Division of Vascular Surgery, Columbia Presbyterian Medical Center, New York, NY.
authors.forename: Roman
authors.initials: R
authors.lastname: Nowygrod
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017544:Aortic Aneurysm, Abdominal / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects / Q000401:mortality / Q000639:trends; D016009:Chi-Square Distribution; D015897:Comorbidity; D016208:Databases, Factual; D057510:Endovascular Procedures / Q000009:adverse effects / Q000401:mortality / Q000639:trends; D005260:Female; D061847:Hospitals, High-Volume; D061846:Hospitals, Low-Volume; D006801:Humans; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D006278:Medicare; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D010360:Patient Transfer / Q000639:trends; D011183:Postoperative Complications / Q000209:etiology / Q000401:mortality; D057216:Propensity Score; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States