title: Steroid withdrawal after renal transplantation: a retrospective cohort study.
abstract: BACKGROUND
  Immunosuppressive regimens in renal transplantation frequently contain corticosteroids, but many centers withdraw steroids as a consequence of unwanted side effects of steroids. The optimal timing to withdraw steroids after transplantation, however, remains unclear. The aim of this study was to determine an optimal time point following kidney transplantation that is associated with reduced mortality without jeopardizing the allograft to allow safe discontinuation of steroids.
  
  
  METHODS
  We conducted a retrospective cohort study and computed a concatenated landmark-stratified Cox supermodel to estimate hazard ratios and 95% confidence intervals for mortality and graft loss using dynamic propensity score matching to adjust for confounding by indication.
  
  
  RESULTS
  A total of 6070 first kidney transplant recipients in the Austrian Dialysis and Transplant Registry who were transplanted between 1990 and 2012 were evaluated and classified according to steroid treatment status throughout follow-up after kidney transplantation; 2142 patients were withdrawn from steroids during the study period. Overall, 1131 patients lost their graft and 821 patients in the study cohort died. Steroid withdrawal within 18 months after transplantation was associated with an increased rate of graft loss compared to steroid maintenance during that time (6 months after transplantation: HR = 1.8; 95% CI, 1.3 to 2.6; 18 months after transplantation: HR = 1.3; 95% CI, 1.1 to 1.6; 24 months after transplantation: HR = 1.2; 95% CI, 0.9 to 1.5), while mortality was not different between groups.
  
  
  CONCLUSIONS
  Our findings suggest that steroid withdrawal after anti-IL-2 induction in the first 18 months after transplantation is associated with an increased risk of allograft loss.
authors.affiliation: Center for Medical Statistics, Informatics and Intelligent Systems (CeMSIIS), Section for Clinical Biometrics, Medical University of Vienna, Spitalgasse 23, Vienna, 1090, Austria.|Department for Internal Medicine III, Nephrology and Hypertension Diseases, Transplantation Medicine and Rheumatology, Krankenhaus Elisabethinen, Linz, Austria.|Methods Support Team ERBP, Ghent University Hospital, Ghent, Belgium.
authors.forename: Maria C
authors.initials: MC
authors.lastname: Haller
authors.affiliation: Center for Medical Statistics, Informatics and Intelligent Systems (CeMSIIS), Section for Clinical Biometrics, Medical University of Vienna, Spitalgasse 23, Vienna, 1090, Austria.
authors.forename: Michael
authors.initials: M
authors.lastname: Kammer
authors.affiliation: Department of Nephrology, Medical University of Vienna, Vienna, Austria.|Department of Nephrology and Dialysis, Medical University of Vienna, University Clinic for Internal Medicine III, Währinger Gürtel 18-20, Vienna, 1090, Austria.
authors.forename: Alexander
authors.initials: A
authors.lastname: Kainz
authors.affiliation: Division of General Internal Medicine and Primary Care, Brigham and Women's Hospital, 1620 Tremont Street, Boston, MA, 02120, USA.|Department of Medicine, Harvard Medical School, Boston, MA, USA.|Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
authors.forename: Heather J
authors.initials: HJ
authors.lastname: Baer
authors.affiliation: Center for Medical Statistics, Informatics and Intelligent Systems (CeMSIIS), Section for Clinical Biometrics, Medical University of Vienna, Spitalgasse 23, Vienna, 1090, Austria.
authors.forename: Georg
authors.initials: G
authors.lastname: Heinze
authors.affiliation: Department of Nephrology, Medical University of Vienna, Vienna, Austria. rainer.oberbauer@meduniwien.ac.at.|Austrian Dialysis and Transplant Registry, Kematen, Austria. rainer.oberbauer@meduniwien.ac.at.|Department of Nephrology and Dialysis, Medical University of Vienna, University Clinic for Internal Medicine III, Währinger Gürtel 18-20, Vienna, 1090, Austria. rainer.oberbauer@meduniwien.ac.at.
authors.forename: Rainer
authors.initials: R
authors.lastname: Oberbauer
mesh_terms: D000328:Adult; D001317:Austria; D015331:Cohort Studies; D004359:Drug Therapy, Combination; D005260:Female; D006084:Graft Rejection / Q000517:prevention & control*; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage / Q000009:adverse effects*; D016030:Kidney Transplantation / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D013256:Steroids / Q000008:administration & dosage* / Q000009:adverse effects; D013375:Substance Withdrawal Syndrome / Q000453:epidemiology*; D014184:Transplantation, Homologous
chemical_list: D007166:Immunosuppressive Agents; D013256:Steroids
keywords: Corticosteroids; Graft loss; Immunosuppression; Kidney transplantation; Steroid maintenance; Steroid withdrawal