DOI: 10.5061/dryad.9s4mw6mdn
title: The benefit of kidney transplantation versus remaining on the waitlist depends on patients' baseline comorbidities: a retrospective study

description: Background: Patients with end-stage renal disease present comorbidities
 that increase mortality risk on the waitlist and after kidney
 transplantation. This study aimed to determine the impact of baseline
 comorbidities on the risk of death after kidney transplantation compared
 to remaining on the waitlist. Methods: Records of waitlisted patients were
 retrospectively analyzed. Multivariable time-dependent Cox-regression
 model was used to determine the initial and the lowest relative
 hazard-risk of death (HRD) after exposure to kidney transplantation.
 Results: 1692 patients were included in the study. Patients without
 comorbidities had the relative HRD 3-fold higher, immediately after kidney
 transplantation, but it reduced progressively, reaching equality to
 waitlist at 75 days and a HRD of 0.28 thereafter (p&lt;0.001).
 Patients with Diabetes and coronary artery disease had an initial relative
 HRD of 2.41 (p=0.009) and 2.68 (p=0.009) and matched to the waitlist at
 175 and 200 days, respectively. Patients with peripheral vascular disease,
 had an initial relative HRD 3.6-fold in the first 240 days (p=0.008) and
 patients with congestive heart failure a relative HRD of 7.47 (p=0.07).
 Both declined rapidly, reaching equality at 110 days. Finally, all
 comorbidities, except cerebrovascular disease, presented lower HRD on
 long-term follow-up. Conclusions: This study shows that the time and the
 range of relative HRD between kidney transplantation and waitlist varies
 depending upon the patients´ baseline comorbidities.
description: We
 retrospectively analyzed the records of all patients waitlisted for the
 first kidney transplantation with deceased donors in our electronic
 database between January 1<sup>st</sup>, 2007 to December
 31<sup>st</sup>, 2012. Before listing,
 patients were evaluated following established international guidelines
 [22-25]. Patients older than 50 years with previous cardiovascular events
 and those with diabetes were evaluated with invasive coronary angiography,
 with intervention when necessary [26-30]. Patients were followed from the
 date of listing through the date of death or July 31st, 2015. Patients who
 lost their follow-up were contacted by phone to report kidney transplant
 in another center or a report, from a relative, of death on the waitlist
 at any time of follow-up. Patients with
 inactive waitlist status at any time of follow-up were not censored at the
 time of de-listing, because these patients were inactivated for
 bureaucratic reasons (lack of blood sample collection periodically,
 requirement of Brazil allocation system) and not for clinical indication.
 Once they fulfilled the requirements they returned as active on the
 waitlist. Transplanted patients
 with primary non-function (PNF), defined as permanent absence of kidney
 function posttransplant [31], or graft loss were censored at the time of
 return to dialysis treatment. Exclusion criteria
 were age under 18 years, previous transplant with another solid organ and
 listed for combined organ transplant. Eighteen patients were also excluded
 because their final waitlist status could not be determined.