2009 ADR v2 Atlas of ESRD - United States Renal Data System

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App A
pg 374
as reported on the OPTN Immunosuppression Treatment form. All
such medications (apart from induction antibodies) are indicated as
maintenance immunosuppression on the form. Figure 7.31 highlights
the switch over time from azathioprine to mycophenolate mofietil
or mycophenolate sodium as the common anti-metabolite. Figure
7.32 contrasts the percent of patients using mTOR inhibitors — sirolimus
or everolimus — at baseline and one year after transplant.
Figure 7.33 contrasts the percent of patients using steroids at baseline
and one year after transplant. Figure 7.34 shows changes in
trends of antibody induction use over time, and Figure 7.35 shows
the most common immunosuppression regimes in adult patients
transplanted during 2005–2007.
GRAFT SURVIVAL
Figure 7.36 shows the percentage of adult transplants with primary
non-function, defined as kidney failure within seven days of transplantation,
while Figure 7.37 illustrates the distribution of eGFR one
year after transplant. Figure 7.38 shows five-year graft survival by
eGFR for patients transplanted in 2000–2005, with graft function at
one year post-transplant. Graft survival rates are estimated using
the Kaplan-Meier method.
Figures 7.39–40 present five- and ten-year graft survival, as well as
conditional half-lives, for adult recipients of kidneys from deceased
and living donors. All estimates are made from Cox proportional
hazards models, adjusted for transplant year, age, gender, race, and
primary diagnosis, and based on the population’s average survival
curves, rather than on curves of the average patient in the population.
Estimates of conditional half-lives are conditional on first-year
graft survival, and estimated from the cumulative hazard between
years one and two. Conditional half-lives are interpreted as the estimated
median survival of grafts surviving the first year, while halflives
are interpreted as the estimated median survival of all grafts.
Figure 7.41 presents one-year post-transplant hospital admission
rates for Medicare patients receiving their first kidney-alone transplant
in 2006. Data are collected from Medicare claims occurring
within a year of discharge from the transplant hospitalization, and
exclude the transplant hospitalization. Admission rates are censored
at graft failure, loss of Medicare coverage, or December 31, 2007.
Statistical methods for computing admission rates are similar to
those described for Reference Section G, but cohorts are constructed
differently. Instead of computing rates in point prevalent patients
within a given year, we define the cohort based on transplant year
and examine hospital claims up to a year post-transplant. Figure
7.42 shows the primary cause of hospitalization for cardiovascular
problems or infection up to three years post-transplant in Medicare
patients who had their first kidney-alone transplant in 2003–2005.
Figure 7.43 presents the one-year cumulative incidence of acute
rejections in adult, first-time, kidney-alone transplant patients discharged
from the transplant hospitalization with a functioning graft.
A patient is assumed to have acute rejection if OPTN data collection
forms note 1) acute rejection episodes, 2) that medications were given
for acute rejection, and that 3) acute rejection was the primary or
secondary cause of graft failure. B3iopsy-proven status was available
starting in 1991 on the OPTN Transplant Recipient Registration,
which identifies early rejection, but was not added to the Transplant
Recipient Follow-up form until April, 2003. Rejections that
are a primary or contributing cause of graft failure are assumed
to be biopsy-proven, while rejections identified by treatment status
are not assumed to be biopsy-proven. Cumulative incidence is
estimated using Kaplan-Meier methods, censored at death or one
year post-transplant.
Figures 7.44–45 present data on post-transplant diabetes and
post-transplant lymphoproliferative disorder (PTLD). The patient
population includes first-time, kidney-only recipients, 2000–2004,
with Medicare as primary payor. To identify de novo post-transplant
diabetes, patients are further required to have six months
of Medicare primary payor coverage prior to transplantation. We
search for claims during this entry period indicating diabetes, and
patients with these claims are omitted. To identify PTLD, we search
Medicare claims for ICD-9-CM diagnosis codes 200.xx, 202.xx, and
204.xx. Only the first three years post-transplant are searched for
each condition, as many transplant recipients lose Medicare coverage
three years post-transplant. For each complication, the figure
shows cumulative incidence over the three-year post-transplant
period; this incidence is estimated from a Cox proportional hazards
model, adjusting for age, gender, race, Hispanic ethnicity, primary
cause of renal failure, year of transplantation, donor type, hepatitis B
and C serology, education level, employment status, time on dialysis,
donor age, donor gender, donor race, HLA mismatches, recipientdonor
body surface area matching, body mass index, panel reactive
antibodies, cytomegalovirus matching, baseline maintenance
immunosuppression (cyclosporin, neoral, tacrolimus, rapamycin,
azathioprine, mycophenolate mofetil), and anti-lymphocyte receptor
antibody use (IL-2, other), and estimated from the population
average curve rather than the curve of the average patient. In Figure
7.45, we overlay PTLD data from OPTN sources in the Medicare
population and in all transplant patient.
In Figure 7.46 we present the rate of return to dialysis/preemptive
retransplantation, the rate of death with a functioning graft,
and the rate of any graft failure, which includes failure due to death.
Rates are limited to adult patients, and estimated from a Poisson
regression, adjusting for age, gender, and race.
Figure 7.47 displays causes of death for adult patients transplanted
between 2003 and 2007 who subsequently die with a functioning
graft. Causes of death are ascertained from OPTN transplant followup
data, or, if unknown, from the ESRD Death Notification form.
Figure 7.48 presents data on graft failures in adults that necessitate
long-term dialysis; graft failures due to death and preemptive
retransplantation are excluded from these counts. Subsequent
treatment is determined from a combination of Medicare claims
and OPTN data.
Figure 7.49 shows the proportion of adult patients who go back
on the wait list or receive a subsequent transplant within a year of
graft failure, while Figure 7.50 shows the median and 25th percentile
for months to retransplantation, and Figure 7.51 shows modality
immediately following graft failure. The y-axis for Figures 7.49–51 is
the year of graft failure. Kaplan-Meier methods are used to compute
rates and time to re-transplantation, with censoring at death with
a functioning kidney. In Figure 7.50, the Kaplan-Meier median is
not observed for patients whose grafts failed after 1999.
REFERENCE SECTION E
Tables E.1–6 present measures regarding the wait list for renal transplantation.
Wait list data prior to 1988 are not shown; the OPTN wait
list began in earnest in 1987. Table E.1 presents counts of patients
newly added to the wait list for a kidney or kidney-pancreas transplant
on December 31 of the given year. Patients listed at multiple
transplant centers are counted only once. Table E.2 presents wait
times, defined as the median time in days from first listing to transplant
among patients listed for a kidney-alone transplant. Kaplan-
Meier methodology is used to estimate median wait times. Table
E.3 presents counts of patients on the wait list on December 31 of