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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

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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

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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!

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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

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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

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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

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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

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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

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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

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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

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+- 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

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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

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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

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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

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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

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DD Kidney Utilization

Estimation of DD kidney graft potential function: • ECD/SCD vs KDPI

Education of potential benefit to recipients

Transplant Center Outcome reports

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% Deaths by Year by DPI among candidates >50 by decade of age

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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

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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

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‘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

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‘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

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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

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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!

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Is the Data Good Enough?

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Thank you