title: Follow-up compliance after endovascular abdominal aortic aneurysm repair in Medicare beneficiaries.
abstract: OBJECTIVE
  Lifelong imaging follow-up is essential to the safe and appropriate management of patients who undergo endovascular abdominal aortic aneurysm repair (EVAR). We sought to evaluate the rate of compliance with imaging follow-up after EVAR and to identify factors associated with being lost to imaging follow-up.
  
  
  METHODS
  We identified a 20% sample of continuously enrolled Medicare beneficiaries who underwent EVAR between 2001 and 2008. Using data through 2010 from Medicare Inpatient, Outpatient, and Carrier files, we identified all abdominal imaging studies that may have been performed for EVAR follow-up. Patients were considered lost to annual imaging follow-up if they did not undergo any abdominal imaging study within their last 2 years of follow-up. Multivariable models were constructed to identify independent factors associated with being lost to annual imaging follow-up.
  
  
  RESULTS
  Among 19,962 patients who underwent EVAR, the incidence of loss to annual imaging follow-up at 5 years after EVAR was 50%. Primary factors associated with being lost to annual imaging follow-up were advanced age (age 65-69 years, reference; age 75-79 years: hazard ratio [HR], 1.23; 95% confidence interval [CI], 1.15-1.32; age 80-85 years: HR, 1.45; 95% CI, 1.35-1.55; age >85 years: HR, 2.03; 95% CI, 1.88-2.20) and presentation with an urgent/emergent intact aneurysm (HR, 1.27; 95% CI, 1.20-1.35) or ruptured aneurysm (HR, 1.84; 95% CI, 1.63-2.08). Additional independent factors included several previously diagnosed chronic diseases and South and West regions of the United States.
  
  
  CONCLUSIONS
  Annual imaging follow-up compliance after EVAR in the United States is significantly below recommended levels. Quality improvement efforts to encourage improved compliance with imaging follow-up, especially in older patients with multiple comorbidities and in those who underwent EVAR urgently or for rupture, are necessary.
authors.affiliation: University of Massachusetts Medical School, Worcester, Mass. Electronic address: andres.schanzer@umassmemorial.org.
authors.forename: Andres
authors.initials: A
authors.lastname: Schanzer
authors.affiliation: University of Massachusetts Medical School, Worcester, Mass.
authors.forename: Louis M
authors.initials: LM
authors.lastname: Messina
authors.affiliation: National Bureau of Economic Research, Cambridge, Mass.
authors.forename: Kaushik
authors.initials: K
authors.lastname: Ghosh
authors.affiliation: University of Massachusetts Medical School, Worcester, Mass.
authors.forename: Jessica P
authors.initials: JP
authors.lastname: Simons
authors.affiliation: University of Massachusetts Medical School, Worcester, Mass.
authors.forename: William P
authors.initials: WP
authors.lastname: Robinson
authors.affiliation: University of Massachusetts Medical School, Worcester, Mass.
authors.forename: Francesco A
authors.initials: FA
authors.lastname: Aiello
authors.affiliation: University of Massachusetts Medical School, Worcester, Mass.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Goldberg
authors.affiliation: University of Massachusetts Medical School, Worcester, Mass; National Bureau of Economic Research, Cambridge, Mass.
authors.forename: Allison B
authors.initials: AB
authors.lastname: Rosen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017544:Aortic Aneurysm, Abdominal / Q000175:diagnosis / Q000453:epidemiology / Q000601:surgery*; D001019:Aortic Rupture / Q000175:diagnosis / Q000453:epidemiology / Q000601:surgery*; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects; D015897:Comorbidity; D003952:Diagnostic Imaging / Q000379:methods*; D017558:Elective Surgical Procedures; D004630:Emergencies; D057510:Endovascular Procedures / Q000009:adverse effects; D005260:Female; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D006278:Medicare; D008875:Middle Aged; D015999:Multivariate Analysis; D010349:Patient Compliance; D011183:Postoperative Complications / Q000175:diagnosis* / Q000453:epidemiology; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology