optn unos kidney committee allocation concepts: not as different as some want you to believe… ken...
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OPTN
UNOS Kidney Committee Allocation Concepts:
Not As Different As Some Want You to Believe…
Ken Andreoni, MD
Chair UNOS Kidney Comm
The Ohio State University
OPTN
DD Kidney Allocation Concepts
We are ONLY talking about standard ADULT Kidney only allocation today. We are NOT talking about:• Kidney with extra-renal organ (LK, HK, KP, etc.)• Pediatric – no change (except KDPI, not age)• Prior Living Donor category• O-MM National Sharing (CPRA >20)• Geography: being thoroughly investigated by other
UNOS committees; complex issue
OPTN
DD Kidney Allocation Concepts
Though we think of allocating 10,000 deceased donor kidneys a year in the US, allocation is one kidney at a time…
• This is why many theoretical allocation concepts do not work in reality!
OPTN
DD Kidney Allocation: Recent Change
0 mm ABDR is local by category of CPRA, then regional or national for CPRA >20 only
• This change has decreased the share of unsensitized 0 mm, and allowed more highly sensitized candidates to be transplanted nationally with less overall shipping of kidneys
OPTN
DD Kidney Allocation: TODAY
Estimation of DD kidney graft potential function: ECD or SCD
If ECD: goes to those on the local ECD list (by wait time)• If not accepted, then regional, then national ECD
lists
If SCD: then all candidates locally by “points”• Wait time, HLA-DR matching (2 pts max), CPRA
(>80 = 4 pts)• Then regional, then national by pts
OPTN
DD Kidney Allocation: TODAY
Most candidates at the top of list mostly by Wait Time• “If I just wait another week/month, could I get a
much better kidney?”• Makes very inefficient use of very useable
kidneys• Patients and Transplant Professionals need
better educational tools to decide about the trade-off: time to transplant vs. quality of organ
OPTN
DD Kidney New Allocation: Concepts (not policy)
Estimation of DD kidney graft potential function: ECD or SCD “KDPI”: < or > 20%
If KDPI is 21 to 100%, first offered to all within 15 years of donor age (30 yr span)• This large group rank ordered (WT, CPRA, HLA)• If not accepted, then to those outside of 15 yrs
local, then regional, then national
If KDPI <=20%; then first to candidates with Est Post-Tx Survival longest 20%• If not accepted, then to all local, then regional,
then national
OPTN
SCD vs ECD: Overlap
Too many candidates are listed for ECD
Waiting for the ‘Good ECD’
0%
5%
10%
15%
20%
25%
DRI Categories
% o
f tr
ansp
lan
ts p
er g
rou
p
SCD ECD (16.6% of total transplants)
Despite this survival overlap, the current system leads to higher discard rates for potential well
functioning kidneys that are labeled ECD
OPTN
KDPI vs ECD
KDPI• Donor age (c)• Race/ethnicity• Hypertension• Diabetes• Serum creatinine (c)• COD CVA• Height• Weight• DCD• HCV
ECD• Donor Age
• >60 alone
• Donor Age• >50 with two below:
• Cr >1.5 • HTN• CVA
• RR of graft failure >1.7 compared to the ‘ideal’ donor (16 – 17%)
OPTN Slide 10
Donor Age v. KDPI
KDPI overlaps substantially for
donors from most age categories
OPTN Slide 11
Donor Age by Recipient Age2005-2007 Transplanted Kidney-Alone Donors
0
10
20
30
40
50
60
70
80
20 - 30 30 - 40 40 - 50 50 - 60 60 - 70 70 - 80 80 - 90
Recipient Age
Don
or A
ge
OPTN
Distribution of Relative Risks for Donor Kidneys: 2004-2007
2.01 2.22 2.47 2.783.26
8.89
1.003.70
1.50 1.66 1.83
1.28
1.35
0123456789
10
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
Percentile Among 2004-2007 Donor Kidneys
RR
Gra
ft F
ailu
re (
DP
I eq
n)
Uses donor factors only
Relative Risk for graft failure is not markedly different for top 20% of kidneys
OPTN
+- 15 years: mostly what we already do…
Median age difference is 14 years in the US• 25% of DD txs <6 yrs
apart• 75% < 26 yrs apart
Donors <35 yo are 41% of donors
Donors <=35, mean recipient age is 49
Recip >65 more than half of donors >50yo
Segev DL. Evaluating Options… AJT 2009; 9:1513-18
OPTN
DD Kidney Utilization
Estimation of DD kidney graft potential function: • ECD/SCD vs KDPI
Education of potential benefit to recipients (and transplant professionals)• Quality of organ vs. prolonged wait time for
better organ
OPTN
Median Expected Survival by Agefor Active Kidney Candidates,
1/1/2004
Wolfe et al, SRTR simulation models
0
10
20
30
40
50
60
20 30 40 50 60 70
Age (years)
Med
ian
Rem
ain
ing
L
ifes
pan
(ye
ars) General Population
With SCD Transplant
With ECD Transplant
Without Transplant
OPTN
Median Expected Survival by AgeMedian Expected Survival by AgeActive Kidney Candidates, 1/1/2004Active Kidney Candidates, 1/1/2004
0
5
10
15
20
25
20 30 40 50 60 70 80
Age at Transplant
Ave
rage
of
Med
ian
Sur
viva
l of
Can
dida
tes
With Average SCD Transplant
Without Transplant
With Average ECD Transplant
Wolfe et al, SRTR Simulation Models
OPTN Slide 17
Recipient Survival by Recipient Age and Donor DPI
32
26
21
15
119
30
25
20
14
118
29
24
19
13
107
28
23
18
129
7
27
21
16
118
6
0
5
10
15
20
25
30
35
20 - 29 30 - 39 40 - 49 50 - 59 60 - 69 70+
Recipient Age
Med
ian
Pat
ien
t S
urv
ival
0 - 19 20 - 39 40 - 59 60 - 79 80 - 100DPI
2005-2007 transplants
OPTN
Hypothetical Output from an Educational Tool to help Candidates and Transplant Professionals Make More
Informed Decisions on Organ Acceptance:Candidate of X yrs old, with Y, Z co-morbidities, living
in a DSA C
123
4
5
OPTNThe easy potential increase in kidney utilization
OPTN
DD Kidney Utilization
Estimation of DD kidney graft potential function: • ECD/SCD vs KDPI
Education of potential benefit to recipients
Transplant Center Outcome reports
OPTN
% Deaths by Year by DPI among candidates >50 by decade of age
OPTN
Big Picture Slide: Most with ESRD do not live to avg. pop lifetime, Transplantation is good for most candidates, young w ESRD lose more years from their expected lifetime
OPTN
Who is the Sickest? Die first?• Like MELD for liver• Then we transplant all sicker and older pts
Who loses the most years from their disease?• 25yo on HD:13 yrs, w Tx:34 yrs• 60yo on HD: 5 yrs, w Tx:12 yrs• 25yo unlikely to reach age 60 w Tx• 25yo will die at <40 yrs of age on HD• 25yo gains 21 yrs of survival, 60yo gains 7 yrs
of survival w Tx• 25yo lives 13 yrs on HD, 60yo lives 12 yrs w Tx
OPTN
‘A Kidney That Looks Like You’ All candidates of all ages have access• Access for most candidates does NOT change• The average candidate will receive the SAME quality
kidney• Will only prevent transplantation across many
decades of age differences
All candidates may benefit…why?• Improvement of utilization of kidneys by KDPI and
understanding of age ranges should increase transplantation of appropriate kidneys, especially to older candidates
• Public understanding of system to increase donation
OPTN
‘A Kidney That Looks Like You’
Living Donation should not be influenced in the negative: No one goes to the front of the line• Whether within 30 year age group, or “top 20%”
everyone within that group is then equal and put in order by variables such as: Wait time, CPRA, HLA, etc., so everyone will wait for their DD offer• NOT similar to the Pediatric Share 35 situation
that occurred in some DSAs
OPTN
Is the Data Good Enough? 80% of organs first to candidate group within 15
years (30 yr range)• Rank-ordered by variables similar to today such as
Wait Time, CPRA, HLA match, etc.• Clinical common sense• Alignment of potential function of organ to post-
transplant potential survival
20% DPI and EPTS• Predictive models are reasonably good to
predict the longest potential functioning organs and longest surviving recipient
OPTN
C Statistic
Measure of “goodness of fit”, or how accurately does this tool tell two people apart everywhere on the list• It gives the same weight to tell number 1
from number 10,000, as it does from telling number 5,000 from number 5,001• The first is important in allocation, the later is
not!
OPTN
Is the Data Good Enough?
OPTN
Thank you
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