title: The effect of delayed graft function on graft and patient survival in kidney transplantation: an approach using competing events analysis.
abstract: OBJECTIVE
  In kidney transplantation, the impact of delayed graft function (DGF) on long-term graft and patient survival is controversial. We examined the impact of DGF on graft and recipient survival by accounting for the possibility that death with graft function may act as a competing risk for allograft failure.
  
  
  METHODS
  We used data from 1281 adult primary deceased-donor kidney recipients whose allografts functioned at least 1 year.
  
  
  RESULTS
  The probability of graft loss occurrence is overestimated using the complement of Kaplan-Meier estimates (1-KM). Both the cause-specific Cox proportional hazard regression model (standard Cox) and the subdistribution hazard regression model proposed by Fine and Gray showed that DGF was associated with shorter time to graft failure (csHR = 2.0, P = 0.002; sHR = 1.57, P = 0.009), independent of acute rejection (AR) and after adjusting for traditional factors associated with graft failure. Regarding patient survival, DGF was a predictor of patient death using the cause-specific Cox model (csHR = 1.57, P = 0.029) but not using the subdistribution model.
  
  
  CONCLUSIONS
  The probability of graft loss from competing end points should not be reported with the 1-KM. Application of a regression model for subdistribution hazard showed that, independent of AR, DGF has a detrimental effect on long-term graft survival, but not on patient survival.
authors.affiliation: Department of Nephrology and Kidney Transplantation, Centro Hospitalar do Porto, Hospital de Santo António, Porto, Portugal.|Unit for Multidisciplinary Investigation in Biomedicine (UMIB), Porto, Portugal.|EPIUnit-Institute of Public Health, University of Porto, Porto, Portugal.
authors.forename: Isabel
authors.initials: I
authors.lastname: Fonseca
authors.affiliation: EPIUnit-Institute of Public Health, University of Porto, Porto, Portugal.|Department of Population Studies, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Porto, Portugal.
authors.forename: Laetitia
authors.initials: L
authors.lastname: Teixeira
authors.affiliation: Department of Nephrology and Kidney Transplantation, Centro Hospitalar do Porto, Hospital de Santo António, Porto, Portugal.|Unit for Multidisciplinary Investigation in Biomedicine (UMIB), Porto, Portugal.
authors.forename: Jorge
authors.initials: J
authors.lastname: Malheiro
authors.affiliation: Department of Nephrology and Kidney Transplantation, Centro Hospitalar do Porto, Hospital de Santo António, Porto, Portugal.|Unit for Multidisciplinary Investigation in Biomedicine (UMIB), Porto, Portugal.
authors.forename: La Salete
authors.initials: LS
authors.lastname: Martins
authors.affiliation: Department of Nephrology and Kidney Transplantation, Centro Hospitalar do Porto, Hospital de Santo António, Porto, Portugal.
authors.forename: Leonídio
authors.initials: L
authors.lastname: Dias
authors.affiliation: Department of Nephrology and Kidney Transplantation, Centro Hospitalar do Porto, Hospital de Santo António, Porto, Portugal.|Unit for Multidisciplinary Investigation in Biomedicine (UMIB), Porto, Portugal.
authors.forename: António
authors.initials: A
authors.lastname: Castro Henriques
authors.affiliation: EPIUnit-Institute of Public Health, University of Porto, Porto, Portugal.|Department of Population Studies, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Porto, Portugal.
authors.forename: Denisa
authors.initials: D
authors.lastname: Mendonça
mesh_terms: D000328:Adult; D000465:Algorithms; D051799:Delayed Graft Function / Q000453:epidemiology*; D005260:Female; D005500:Follow-Up Studies; D006084:Graft Rejection; D006085:Graft Survival; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D016030:Kidney Transplantation / Q000379:methods / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012044:Regression Analysis; D012189:Retrospective Studies; D012307:Risk Factors; D014019:Tissue Donors; D016896:Treatment Outcome
keywords: competing risks analysis; delayed graft function; kidney transplantation; long-term graft failure; patient death with graft function; subdistribution hazard regression model