title: Multi-state survival analysis in renal transplantation recipients.
abstract: BACKGROUND
  Renal transplantation is a therapy for end-stage renal disease. During the study of recipients' survival after renal transplantation, there are some events as intermediate events that not only affect the recipients' survival but also events which are affected by various factors. The aim of this study was to handle these intermediate events in order to identify factors that affect recipients' survival by using multi-state models.
  
  
  METHODS
  This retrospective cohort study included 405 renal transplant patients from Afzalipour Hospital, Kerman, Iran, from 2004 to 2010. The survival time of these recipients was determined after transplantation and the effect of various factors on the death hazard with and without renal allograft failure and hazard of renal allograft failure was studied by using multi-state models.
  
  
  RESULTS
  During 4.06 years (median) of follow-up; 28 (6.9%) recipients died and allograft failure occurred in 51 (12.6%) recipients. Based on the results of multi-state model, receiving a living kidney transplantation decreased the hazard of renal allograft failure (HR=0.38; 95% CI: 0.17- 0.87), pre-transplant hypertension (HR=2.94; 95% CI: 1.54- 5.63) and serum creatinine levels >1.6 upon discharge from the hospital (HR=7.38; 95% CI: 3.87- 7.08) increased the hazard of renal allograft failure. Receiving living kidney transplantation decreased the hazard of death directly (HR=0.18; 95% CI: 0.04- 0.93).
  
  
  CONCLUSIONS
  It was concluded that the effect of donor type, pre-transplant hypertension and having serum creatinine >1.6 upon discharge from the hospital was significant on hazard of renal allograft failure. The only variable that had a direct significant effect on hazard of death was donor type.
authors.affiliation: 1. Dept. of Epidemiology and Biostatistics, Tehran University of Medical Sciences , Tehran, Iran.
authors.forename: Moghaddameh
authors.initials: M
authors.lastname: Mirzaee
authors.affiliation: 1. Dept. of Epidemiology and Biostatistics, Tehran University of Medical Sciences , Tehran, Iran.
authors.forename: Kazem
authors.initials: K
authors.lastname: Mohammad
authors.affiliation: 1. Dept. of Epidemiology and Biostatistics, Tehran University of Medical Sciences , Tehran, Iran.
authors.forename: Mahmood
authors.initials: M
authors.lastname: Mahmoodi
authors.affiliation: 1. Dept. of Epidemiology and Biostatistics, Tehran University of Medical Sciences , Tehran, Iran.
authors.forename: Hojjat
authors.initials: H
authors.lastname: Zeraati
authors.affiliation: 2. Physiology Research Center, Departments of Nephrology, Urology and Renal Transplantation, Kerman University of Medical Sciences , Kerman, Iran.
authors.forename: Mohammad-Reza
authors.initials: MR
authors.lastname: Ebadzadeh
authors.affiliation: 2. Physiology Research Center, Departments of Nephrology, Urology and Renal Transplantation, Kerman University of Medical Sciences , Kerman, Iran.
authors.forename: Abbas
authors.initials: A
authors.lastname: Etminan
authors.affiliation: 3. Dept. of Urology, Zahedan University of Medical Sciences , Zahedan, Iran.
authors.forename: Faramarz
authors.initials: F
authors.lastname: Fazeli
authors.affiliation: 2. Physiology Research Center, Departments of Nephrology, Urology and Renal Transplantation, Kerman University of Medical Sciences , Kerman, Iran.
authors.forename: Mohammad Hasan
authors.initials: MH
authors.lastname: Dehghani Firouzabadi
authors.affiliation: 2. Physiology Research Center, Departments of Nephrology, Urology and Renal Transplantation, Kerman University of Medical Sciences , Kerman, Iran.
authors.forename: Hossein
authors.initials: H
authors.lastname: Sattary
authors.affiliation: 2. Physiology Research Center, Departments of Nephrology, Urology and Renal Transplantation, Kerman University of Medical Sciences , Kerman, Iran.
authors.forename: Mahdiyeh
authors.initials: M
authors.lastname: Haghparast
authors.affiliation: 1. Dept. of Epidemiology and Biostatistics, Tehran University of Medical Sciences , Tehran, Iran.
authors.forename: Abbas
authors.initials: A
authors.lastname: Rahimi Foroushani
keywords: Death hazard; Intermediate event; Multi-state model; Renal transplantation