title: Bronchiolitis obliterans syndrome occurs earlier in the post-lung allocation score era.
abstract: OBJECTIVE
  In 2005, the time-based waiting list for lung transplantation was replaced by an illness/benefit lung allocation score (LAS). Although short-term outcomes after transplantation have been reported to be similar before and after the new system, little is known about long-term results. The objective of this study was to evaluate the impact of LAS on the development of bronchiolitis obliterans syndrome as well as on overall 3-year and bronchiolitis obliterans syndrome-related survival.
  
  
  METHODS
  Data obtained from the United Network for Organ Sharing were used to review 8091 patients who underwent lung transplantation from 2002 to 2008. Patients were stratified according to time of transplantation into those treated before initiation of the LAS (pre-LAS group, January 2002-April 2005, n = 3729) and those treated after implementation of the score (post-LAS group, May 2005-May 2008, n = 4362). Overall, 3-year survivals for patient groups were compared using a univariate analysis, Cox proportional hazards model to generate a relative risk, and Kaplan-Meier curve analyses.
  
  
  RESULTS
  During the 3-year follow-up period, bronchiolitis obliterans syndrome developed in 22% of lung transplant recipients (n = 1801). Although the incidence of postoperative bronchiolitis obliterans syndrome development was similar between groups, post-LAS patients incurred fewer bronchiolitis obliterans syndrome-free days (609 ± 7.5 vs 682 ± 9; P <.0001; log-rank test P = .0108) than did pre-LAS patients. Overall 3-year survival was lower in post-LAS patients and approached statistical significance (P = .05). Similarly, bronchiolitis obliterans syndrome-related survival was worse for patients in the post-LAS group (log-rank test P = .01).
  
  
  CONCLUSIONS
  In the current LAS era, lung transplant recipients have significantly fewer bronchiolitis obliterans syndrome-free days after 3-year follow-up. Compared with the pre-LAS population, overall and bronchiolitis obliterans syndrome-related survival appears worse in the post-LAS era. Limitation of known risk factors for development of bronchiolitis obliterans syndrome-may prove even more important in this patient population.
authors.affiliation: Department of Surgery, University of Virginia, Charlottesville, Va 22908-0679, USA.
authors.forename: Abbas
authors.initials: A
authors.lastname: Emaminia
authors.forename: Sara A
authors.initials: SA
authors.lastname: Hennessy
authors.forename: Tjasa
authors.initials: T
authors.lastname: Hranjec
authors.forename: Damien J
authors.initials: DJ
authors.lastname: LaPar
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Kozower
authors.forename: David R
authors.initials: DR
authors.lastname: Jones
authors.forename: Irving L
authors.initials: IL
authors.lastname: Kron
authors.forename: Christine L
authors.initials: CL
authors.lastname: Lau
mesh_terms: D000328:Adult; D000368:Aged; D001989:Bronchiolitis Obliterans / Q000209:etiology* / Q000401:mortality; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D016040:Lung Transplantation / Q000009:adverse effects* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D016016:Proportional Hazards Models; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D015996:Survival Rate; D013577:Syndrome; D013997:Time Factors; D009927:Tissue and Organ Procurement; D016896:Treatment Outcome; D014481:United States; D014850:Waiting Lists