title: Does the UNOS heart transplant allocation system favor men over women?
abstract: OBJECTIVE
  The aim of this paper was to identify sex differences in survival of patients awaiting orthotopic heart transplantation (OHT).
  
  
  BACKGROUND
  Women have a higher mortality rate while awaiting OHT than men, and the reason has not been fully determined.
  
  
  METHODS
  We included all adult patients in the Scientific Registry of Transplant Recipients (SRTR) placed on the OHT waiting list from 2000 to 2010. The primary endpoint was all-cause mortality before receiving OHT, analyzed using time-to-event analysis. Multivariate Cox proportional hazards models were used to evaluate sex differences in survival, with data stratified by United Network for Organ Sharing (UNOS) status at time of listing.
  
  
  RESULTS
  There were 28,852 patients (24% women) awaiting OHT. This cohort included 6,163 UNOS status 1A (25% women), 9,168 UNOS status 1B (25% women), and 13,521 UNOS status 2 (24% women) patients. During a median follow-up of 3.7 years, 1,290 women and 4,286 men died. Female sex was associated with a significant risk of death among UNOS status 1A (adjusted hazard ratio [HR]: 1.20; 95% confidence interval [CI]: 1.05 to 1.37, p = 0.01) after adjusting for more than 30 baseline variables. In contrast, female sex was significantly protective for time to death among UNOS status 2 patients (adjusted HR: 0.75; 95% CI: 0.67 to 0.84, p < 0.001). No sex differences were noted among UNOS status 1B patients.
  
  
  CONCLUSIONS
  There are sex differences in survival between women and men awaiting heart transplantation, and the current UNOS transplant criteria do not account for this disparity.
authors.affiliation: Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio; Cleveland Clinic, Lerner College of Medicine of Case Western Reserve University School of Medicine, Cleveland, Ohio. Electronic address: Hsiche@ccf.org.
authors.forename: Eileen M
authors.initials: EM
authors.lastname: Hsich
authors.affiliation: Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio; Cleveland Clinic, Lerner College of Medicine of Case Western Reserve University School of Medicine, Cleveland, Ohio.
authors.forename: Randall C
authors.initials: RC
authors.lastname: Starling
authors.affiliation: Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio; Cleveland Clinic, Lerner College of Medicine of Case Western Reserve University School of Medicine, Cleveland, Ohio; Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, Ohio.
authors.forename: Eugene H
authors.initials: EH
authors.lastname: Blackstone
authors.affiliation: Department of Cardiology, Boston Children's Hospital, Boston, Massachusetts; Harvard Medical School, Boston, Massachusetts.
authors.forename: Tajinder P
authors.initials: TP
authors.lastname: Singh
authors.affiliation: Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio.
authors.forename: James B
authors.initials: JB
authors.lastname: Young
authors.affiliation: Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio.
authors.forename: Eiran Z
authors.initials: EZ
authors.lastname: Gorodeski
authors.affiliation: Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio.
authors.forename: David O
authors.initials: DO
authors.lastname: Taylor
authors.affiliation: Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, Ohio.
authors.forename: Jesse D
authors.initials: JD
authors.lastname: Schold
mesh_terms: D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000401:mortality* / Q000601:surgery; D016027:Heart Transplantation / Q000401:mortality*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D040841:Resource Allocation / Q000379:methods*; D017678:Sex Distribution; D014481:United States / Q000453:epidemiology; D014850:Waiting Lists / Q000401:mortality
keywords: heart failure; mortality; sex; transplantation