FAIRNESS/EQUITY UTILITY/EFFICACY EFFICIENCY. The new kidney allocation system (KAS) what has it done? 9/26/2018. Disclosures

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1 The new kidney allocation system (KAS) what has it done? Disclosures No financial disclosure Ryutaro Hirose, MD Professor in Clinical Surgery University of California San Francisco Objectives Describe Guiding principles of organ allocation policyu Organ allocation and distribution guiding general principles FAIRNESS/EQUITY UTILITY/EFFICACY EFFICIENCY 1

2 FINAL RULE Organ allocation policy NEW UNOS Kidney allocation system Implemented on Dec 4, 2014 Attempts to match best kidneys with best candidates Prioritizes highly sensitized patients Unifies fragmented variances Four Problems KAS Aimed to Solve Problem #1: Longevity mismatches 1. Longevity mismatches 2. Biological and ethnic inequities 3. Too many discarded kidneys 4. Fragmented, non unified system Recipient Donor Source: a man who is almost twice my age/ xo5s9/index.html 2

3 Longevity Mismatches During the one year before KAS, 567 kidneys from year old donors went to age 65+ recipients. 16.1% of age donor kidneys KDRI DONOR FACTORS Age Height Weight Ethnicity (African American) Hypertension Diabetes Serum Creatinine HCV + DCD KDPI and graft survival Estimated post transplant survival score EPTS Age Diabetes Duration of dialysis Previous transplant C statistic =

4 EPTS and outcome KDPI & EPTS in the New System KDPI 0-20% Longevity Matching EPTS 0-20% Kidney donor profile index (KDPI) Estimated post transplant survival score (EPTS) Sequence A KDPI <=20% Sequence B KDPI >20% but <35% Sequence C KDPI >=35% but <=85% Sequence D KDPI>85% Local CPRA 100 Regional CPRA 100 National CPRA 100 Local CPRA 99 Regional CPRA 99 Local CPRA 98 Zero mismatch (top 20% EPTS) Prior living donor Local pediatrics Local top 20% EPTS Zero mismatch (all) Local (all) Regional pediatrics Regional (top 20%) Regional (all) National pediatrics National (top 20%) National (all) Local CPRA 100 Regional CPRA 100 National CPRA 100 Local CPRA 99 Regional CPRA 99 Local CPRA 98 Zero mismatch Prior living donor Local pediatrics Local adults Regional pediatrics Regional adults National pediatrics National adults Local CPRA 100 Regional CPRA 100 National CPRA 100 Local CPRA 99 Regional CPRA 99 Local CPRA 98 Zero mismatch Prior living donor Local Regional National Local CPRA 100 Regional CPRA 100 National CPRA 100 Local CPRA 99 Regional CPRA 99 Local CPRA 98 Zero mismatch Local + Regional National 4

5 Relationship between KDRI and KDPI Estimated Post Transplant Survival (EPTS) Score KDRI KDPI 1% 15% 20% 40% 50% 70% 85% 99% Higher Quality, Longevity Lower Quality, Longevity Time on dialysis Current diagnosis of diabetes Candidate s age Any prior solid organ transplant EPTS score range 0% 100% Longevity-matching under KAS Longevity-matching under KAS During the 1 year before after KAS, kidneys from year old donors went to age 65+ recipients. 16.1% 10.1% of age donor kidneys KDPI 0-20% / age 65+ recipients: pre-kas 3.2%, post-kas 1.1% 5

6 Did KAS Affect Equity by Recipient Age? Deceased Donor Kidney Transplant Rates Problem #2: Biological and ethnic inequity 67% 10% Transplants per patient-year by candidate CPRA How did KAS increase biological equity? 7x Sliding scale CPRA points Local, regional, national priority 1 transplant in 5 years 1 transplant in 2 years 1 in 25 years 1 in 100 years 4x 13x Old CPRA CPRA CPRA 6

7 CPRA % recipient bolus effect 20% 18% 17.7% % of Transplants to CPRA % Recipients More Kidneys are Being Shipped under KAS Local 80% 70% 16% 14% 14.6% 12% 10% 10.6% 12.3% 10.2% 8% 8.7% (May 2017) 6% 4% 1.8% 2% 0% 3.5% 2.4% Cold ischemic time hours Transplants to CPRA % patients rose sharply after KAS but have tapered to around 10% nationally. 25 KAS gives credit for pre-listing dialysis time Patient started dialysis Patient added to waiting list Waiting time priority before KAS Waiting time priority under KAS Young black patients much less likely to be presented option of transplantation around time of starting dialysis. 7

8 Kidney Transplants by Race/Ethnicity 50% Waitlist (11/30/2014) 41.8% Pre KAS (1 year) 36.8% 36.5% 34.3% 35.4% Post KAS (1 year) 31.5% High dialysis time recipient bolus effect 20.0% 18.6% 18.0% 16.0% 14.0% % of Transplants to Recipients with 10+ Years on Dialysis 25% 12.0% 12.4% 19.2% 18.6% 17.0% 10.0% 0% 7.9% 7.3% 6.8% 1.2% 0.6% 0.7% 0.7% 1.1% 1.3% 0.5% 0.5% 0.5% 8.0% 6.0% 4.0% 6.2% 3.3% 4.5% 7.5% 7.1% (Dec 2016) 6.0% 2.0% 0.0% KAS Under KAS, Blacks are now receiving transplants proportional to their representation on the waiting list. Based on dialysis date from TRR After KAS, the % of transplants to recipients with 10+ years of dialysis rose sharply to nearly 19% but has tapered to about 6% nationally. 30 But what about post-transplant outcomes under KAS? Delayed graft function (DGF) rates DGF = dialysis within first week More younger (EPTS 0-20%) recipients Improved longevity matching Better outcomes More sensitized recipients Higher cold ischemic times Fewer 0-ABDR mismatches More high dialysis time recipients Worse outcomes The percentage of recipients requiring dialysis within the first week after transplant increased from 24.3% pre KAS to 29.5% after KAS. Increase driven by more high dialysis time recipients and other factors. 32 8

9 1-Year Graft Survival Pre vs. Post-KAS 1-Year Patient Survival Pre vs. Post-KAS Graft survival at one year very similar, though slightly lower, post-kas (93.6%) compared to pre-kas (94.1%). Patient survival at one year very similar, though slightly lower, post-kas (96.2%) compared to pre-kas (96.9%). Problem #3: Too many discarded kidneys Kidney Donor Trends Source: Stewart, D. E., Garcia, V. C., Rosendale, J. D., Klassen, D. K., & Carrico, B. J. (2017). Diagnosing the Decades-Long Rise in the Deceased Donor Kidney Discard Rate in the US. Transplantation. Long-run increasing trend in median age, BMI, and KDRI among recovered kidney donors

10 Explaining the Kidney Discard Rate Trend ( ) Kidney Discard Rate Trend Source: Stewart, D. E., Garcia, V. C., Rosendale, J. D., Klassen, D. K., & Carrico, B. J. (2017). Diagnosing the Decades-Long Rise in the Deceased Donor Kidney Discard Rate in the US. Transplantation. Thru Apr % rise Flat 37 KAS (Dec 4, 2014) Kidney Discard Rate: Pre (~5 years) vs. Post KAS (16 months) P-value=0.003 Kidney Discard Rate: Pre (~5 years) vs. Post KAS (16 months) (p<0.0001) RR=1.08 OR=1.10 (p=0.55) (p=0.08) (Jan 1, Dec 3, 2014) (Dec 4, Mar 31, 2016) Stewart D., et al, ATC, 2016 Statistically significant rise in discard rates post KAS. Statistically significant rise for higher KDPI kidneys. 10

11 Did KAS Solve the 4 Problems? 1. Reduce longevity mismatches? Yes 2. Reduce biological (and other) inequity? Yes 3. Reduce kidney discard rate? No 4. Unified national system? Yes What other problems remain? Long waiting times (not enough kidneys) Candidate blood type disparities Geographic inequity Long term outcomes? Unknown Multi organ inequity The Final Rule organ allocation Organ allocation policies and procedures shall be in accordance with sound medical judgment and shall be designed and implemented: To allocate organs among transplant candidates in order of decreasing medical urgency status, with waiting time in status used to break ties within status groups. Neither place of residence nor place of listing shall be a major determinant of access to a transplant. Priority shall be given to reducing the waiting time variance in the most medically urgent status categories before reducing the waiting time variance in less urgent status categories, if equivalent reductions cannot be achieved in all status categories; and To avoid futile transplantation, to avoid wasting organs, and to promote efficient management of organ placement. The UNOS kidney committee has yet to tackle geographic inequity Huge variation in wait times, transplant rates for kidney recipients by geography Center Waitlist Volume DD % txp at 1 yr % txp at 2 yrs % txp at 3 years Transplant Rate UCSF 4, % 4.4% 6.4% CPMC 1, % 8.1% 11.7% UCLA 2, % 15.1% 18.3% Ohio St % 14.7% 23.6% U Wisconsin % 34.1% 41.7% U.S. 106,306 26, % 16.8% 22.6% 11

12 Summary KAS has improved equity & longevity matching Impact on long term outcomes is unclear More work needed to improve kidney utilization Geographic disparities remain a significant challenge The UNOS kidney committee will have to work to eliminate DSA as a unit of distribution (as has the liver service in its proposals.stay tuned!!!! FINAL RULE Organ allocation policy 45 Recent letter from HRSA administrator Not just the liver.. 12

13 Geographic inequity in liver distribution Two competing new proposals are being modelled SRTR will have modeling completed next week! (September 24) Both involve circles (distance) as the distribution areas One (favors local supremacy) put forward by those opposed to wider distribution One emphasizes sickest first, but given equal degrees of illness, favor more proximal candidates to the donor location (my proposal) Thank you! Complex interplay between OPOs and transplant centers. 13