Saturday, December 6, 2014

DO THE NEW UNOS KIDNEY ALLOCATION STANDARDS DISCRIMINATE AGAINST THE MATURE KIDNEY PAITENT?





NEW UNOS STANDARDS FOR KIDNEY ALLOCATION:

DO THEY DISCRIMINATE AGAINST THE OLDER PATIENT?

BY JAMES MYERS

 

          A while back, I was sitting in my kidney transplant surgeons’ office at the University of Wisconsin, discussing kidney transplantation.  He drew 4 boxes on a sheet of paper.  Pointing from left to right, he said, “These boxes represent age divisions of potential donors from the youngest group to the oldest.” Then he drew an X through the far left- side box.  “Under the new rules, you will be no longer be eligible to receive a cadaver kidney from this group.”  This was my first exposure to the new UNOS kidney allocation rules that come into effect December 4, 2014.[i]  It is my belief that the new rules discriminate against the more mature kidney patient.

          According to UNOS, the new rules, are designed to create a significant increase in the life years of transplants. [ii] To do this, UNOS has designed a kidney allocation plan that, “would give more kidneys to younger, healthier patients in an effort to achieve greater survival time from each transplant.[iii]  It is my contention that the new standards favor the younger kidney patient and discriminate against the older kidney patient. [iv]

          The key to all of this is that UNOS has moved from a waiting time allocation standard to a risk quantification score; how long will the kidney last and how long will the recipient last. The longer lasting kidneys will go to the longer lasting recipients.[v]  In the eyes of UNOS, the current standards do not account for kidney longevity; will the person who receives a cadaver kidney live as long as the kidney is expected to last?[vi] The new system was allegedly put into place to alleviate this issue and in affect to make certain that people with longer life expectancies (younger persons) receive kidneys with a like longer life expectancies.[vii]  According to UNOS, 80% of us will be unaffected by the new kidney allocation rules[viii], and the rules have no effect over living donor donation or paired matched donation. [ix]

“The new system outlined by UNOS' Kidney Transplantation Committee would give the highest-quality kidneys to the 20% of recipients with the longest estimated post-transplant survival time. The other 80% of kidneys would be matched roughly by age, with recipients 15 years older or younger than the age of the deceased donor getting the highest priority.[x]

 

          The key to the new rules is that the effect the new kidney allocation rules have on the patient is based on his clinical circumstances.

“"The No. 1 reason we lose a kidney transplant is that the patient dies with a kidney working," said Dr. Formica, a nephrologist.  "We'd like for that to happen less often. If you have a kidney from an 18-year-old donor that is likely to last, say, 12 years, it would be much better to have that kidney in a 30-year-old and have that 30-year-old get the maximal life expected from that kidney than have that kidney in a 75-year-old where the person would likely die only having used five years of the expected life of that kidney. We'd rather take the kidney expected to last six years and give it to the 75-year-old.[xi]"

 

          The new system has been justified by the following statistics:

“The proportion of kidneys going to younger recipients has fallen steadily since 1990, while the percentage going to older patients has risen. In 1990, for example, 30% of kidneys went to recipients between ages 18 and 34 and 23% went to adults 50 to 64, according to the committee's paper. By 2009, just 13% of kidneys went to patients 18 to 34 years-old while 39% went to those between 50 and 64.

 

The life span of patients after receiving a kidney transplant has fallen by 18 months since 1995, according to estimates published March 16 in The New England Journal of Medicine by researchers at the University of Michigan Medical School and the Arbor Research Collaborative for Health, both in Ann Arbor, Mich.[xii]

 

          Some professionals are not so sure:

          “The new approach would hurt older patients, said Lainie Friedman Ross, MD, PhD, associate director of the University of Chicago MacLean Center for Clinical Medical Ethics. “One of my big concerns is given how it's structured, most kidneys go to younger people," Dr. Ross said. "I would argue that it's discrimination against people who are older. If the allocation plan were changed, more than 1,100 kidneys would go to patients 50 and younger instead of going to people older than 50, the committee estimates.[xiii]

 

Dr. Ross said she does not trust the simulations used by the committee to estimate the effect of potential changes because they were done on a national basis, whereas kidney allocation takes place on a regional basis and varies widely, depending on the number of candidates and donors in an area.  She said the committee did not take into account the potential effect of changes on living donors. If younger patients have greater and faster access to deceased donor kidneys, they may be less likely to ask loved ones to donate to them -- decreasing the total number of kidneys available to transplant.[xiv]

EARLY REFERRAL FOR A TRANSPLANT

WHEN IS THE BEST TIME TO BE REFERRED FOR A TRANSPLANT?

 

The new rules also change the basic philosophy on when is the best time to be referred for a transplant.  Under the new rules, the goals is that every patient be referred as soon as possible.[xv]  Patients can now be placed on the list before they start dialysis.[xvi]

While waiting time is now being calculated to include pre-registration dialysis time, the GFR value criteria remains the same and patients can accrue waiting time points based on this criteria alone.[xvii]

In addition, the new allocation system continues to prioritize for zero antigen mismatches, which often do not require significant waiting time in order to receive these offers.[xviii]

 

 

 

WAITING TIME-HOW LONG WILL A KIDNEY PATIENT WAIT FOR A TRANSPLANT

          While waiting time is still a factor in receiving a kidney, there is some good news here.  First, patients will receive time credits for time waiting before dialysis.[xix]  Second, your wait time will be wound back to the actual date you started dialysis.[xx]  This has been done because 85% of patients currently have less than 3 years of pre-transplant time, while only 7% of the patients have than 5 years.[xxi]  For adults, the waiting time starts when registered or date of first dialysis or GFR or CRCL is = or < 20 ml/min.

 The bottom line is in the new system, waiting time priority will remain a key factor in allocation.[xxii]  Adults will be assigned waiting time points for time on dialysis prior to registration, meaning that they receive a credit for time spent on dialysis prior to listing. This recognizes that prioritization for transplant is based on a patient’s medical need and time on dialysis is an indication of time spent with ESRD.[xxiii]

However, the policy that allows a patient to begin accruing waiting time points at/after registration for a GFR value equal to or less than 20 remains unchanged. In other words, patients will not receive backdated time for the GFR value criteria.[xxiv]

For pediatric patients, waiting time begins immediately at the time of registration.[xxv] 

 

THE IMPORTANCE OF THE KIDNEY DONOR PROFILE INDEX (KDPI)

          The Kidney Donor Profile Index (KDPI) is a new quantification system to determine the suitability of a particular kidney for a particular patient.[xxvi]  The old classifications for kidney allocation, “standard criteria" or "expanded criteria", without any distinction of donor kidneys within each group, have been discarded.[xxvii]  Now ever kidney offered will have a KDPI score.[xxviii] The key here is that the KDPI results in a percentage.  The lower the percentage, the better the organ is, at least in terms of how long they expect it to last. [xxix] The longer the kidney will last is an indicator of to whom the kidney will go to.  That kidney will go to the person who has the longer corresponding life expectancy, i.e. the younger patient. [xxx] KDPI summarizes 10 donor factors associated with the number of years a transplanted kidney is expected to function including:

                                                             i.      Age

                                                          ii.      Height & Weight

                                                       iii.      Ethnicity

                                                       iv.      History Of HBP

                                                          v.      History Of Diabetes

                                                       vi.      Stroke As A Cause Of Death

                                                    vii.      Serum Creatine

                                                 viii.      Exposure Hepatitis C Virus

                                                       ix.      Death Due To Loss Of Heart Or Brain Function

 

So what is considered a good score?  The KDPI ranges from 0-100%.[xxxi]  A lower score suggests the kidney will last longer, have a longer function time, while a higher KDPI score suggests a lower, lessor function time.[xxxii] For example, a kidney with a 0-20% score is expected to last 11.5 years after a transplant; a kidney with a 21-85% score will last over 5 years, while a score of over 85% lasts 5 ½ years.[xxxiii]

The pitch we’re getting from UNOS here is that if you are willing to accept a kidney with a KDPI score of over 85%, you may get your kidney sooner.[xxxiv] This to me on its face, appears to be a way to move older patients off of the list.  Although there is always a chance the >85% may last more than 5 years, it still seems relatively short to me, and maybe a ticket back to dialysis.  There is a chart to help you determine the amount of time you can expect a kidney to last that matches your KDPI[xxxv]:

 

View image on Twitter

 

What this means is that is you have a KDPI of 82%, the donor organs has a failure rate that is 82% higher than other donor kidneys.

 

 

 

 

WHAT IS THE DIFFERENCE FOR PEDIATRIC PATIENTS?

Pediatric patients under the age of 18 will maintain their current access to kidneys but will receive priority donors with KDPI of less than 35% instead of donors age 35 in the current system.[xxxvi]  The emphasis is clearly on the longer lasting kidneys to the longer lasting patients. There are other patient specific factors than KDPI that are taken into account.[xxxvii]

ESTIMATED POST TRANSPLANT SURVIVAL SCORE (EPTS)

The Estimated Post Transplant Survival Score (EPTS) also plays a role in the new kidney allocation.  The EPTS refers to your expected post-transplant survival rate as a patient. [xxxviii] The EPTS score is specific to each patient.[xxxix] Factors include:

                                                             i.            Age

                                                          ii.            Time On Dialysis

                                                       iii.            Current Diagnosis Of Diabetes

                                                       iv.            Prior Organ Transplant (Heart, Kidney, Liver, Pancreas, Etc.[xl]

 

Again, it is a score that ranges from 0-100%.[xli]  Every adult candidate registered for a transplant, will now receive an EPTS score.[xlii] An EPTS score will be calculated, but not used for a transplant candidate under the age of 18.[xliii] The groups of patients are broken down into 2 groups for EPTS scores:

i.                   Candidates with a score of 20% or less;

ii.                Candidates with a score of more than 20%

A lower EPTS score means that you are expected to have more years of function from the donor kidney compared to patients with higher EPTS scores.[xliv]  A higher EPTS score means the patient is expected to have less years of function needed. [xlv] If patient is in the first group, he is likely to need a kidney longer; they are likely to need a kidney longer than 80% of the people listed for a transplant.[xlvi] This gives them increased priority for a kidney that is expected to function the longest.[xlvii]  Patients registered before they start dialysis are more likely to have an EPTS score under 20%.[xlviii]

If the patient is in the 2d group, with an EPTS over 20%, say a score of 60%, they are likely to need a kidney that lasts longer than 40% of other listed patients.[xlix] In general patients with lower EPTS scores tend to be younger in age[l], and those with diabetes tend to have higher EPTS scores.[li] Patients who have had prior transplants or been on dialysis for a number of years tend to have higher EPTS scores.[lii] Patients in the < 20% group therefore have a higher priority to receive the longer lasting kidneys in the KDPI group.[liii] Patients in the > 20% group receive no distinguished status.[liv]

UNOS Simulation/Projections Under the New Standards

According to the Journal of the American Association of Nephrology,[lv] when a simulation was done to determine how kidneys would be allocated under the new policy, the group found that with the new policy, candidates with a CPRA>20%, with blood type B, and aged 18–49 years were more likely to undergo transplant, but transplants declined in candidates aged 50–64 years (4.1% decline) and ≥65 years (2.7% declined)[lvi].

 

 

Conclusion

In my opinion, the new standards favor the younger kidney patient.  I have questions.  First, if we are implanting the best kidneys in the youngest patients, are we still not looking at multiple potential transplants in their lifetime?  Second, are we still not looking at multiple transplants in the lifetime of a more mature patient? Third, is there an issue with compliance?  You have to be religious about your medications on a post-transplant course, are the younger patients or the more mature patient more compliant in these circumstances?  These are questions that remain to be seen and can only be answered by experience.

One last thing, I am not opposed to younger patients getting their opportunity for transplant.  I am concerned about the potential effect on the mature patient.  I think some difficult choices lie ahead.

 

 

ENDNOTE




[i] Kidney Allocation System (KAS), http://transplantpro.org/kidney-allocation-system/ (Accessed 2014).
 
[ii] Video, The Kidney Allocation System, What Candidates Need to Know, http://vimeo.com/107481347 (Accessed 2014).
 
 
[iii] O’Reilly, Kidney Transplant Plan Would Give Preference to Younger Patients, http://www.amednews.com/article/20110328/profession/303289943/7/ (March 28, 2011); Neurology on Demand, The New Kidney Allocation System, https://storify.com/nephondemand/the-new-kidney-transplant-allocation-system (Accessed 2014); Video, The Kidney Allocation System, What Candidates Need to Know, http://vimeo.com/107481347 (Accessed 2014).
 
 
[iv] O’Reilly, Kidney transplant plan would give preference to younger patients, http://www.amednews.com/article/20110328/profession/303289943/7/ (March 28, 2011).
 
 
[v] Benjamin E. Hippen, M.D., J. Richard Thistlethwaite, Jr., M.D., Ph.D., and Lainie Friedman Ross, M.D., Ph.D., Risk, Prognosis, and Unintended Consequences in Kidney Allocation (April 7, 2011). (“the proposal makes
clear that allocating top-quintile organs to top-quintile candidates will come at the expense of the
overall opportunities for older candidates on the waiting list to be offered a kidney from a deceased
donor.”)
 
[vi] The New Kidney Transplant Allocation System, https://storify.com/nephondemand/the-new-kidney-transplant-allocation-system, (Accessed 2014).
 
 
[vii] O’Reilly, Kidney Transplant Plan Would Give Preference to Younger Patients, http://www.amednews.com/article/20110328/profession/303289943/7/ (March 28, 2011); Neurology on Demand, The New Kidney Allocation System, https://storify.com/nephondemand/the-new-kidney-transplant-allocation-system (Accessed 2014); Video, The Kidney Allocation System, What Candidates Need to Know, http://vimeo.com/107481347 (Accessed 2014).
 
 
[viii] Talking About Transplantation, Question And Answers for Kidney Transplant Candidates About Kidney Allocation, http://www.unos.org/docs/Kidney_Brochure.pdf (Accessed 2014).
 
 
[ix] O’Reilly, Kidney Transplant Plan Would Give Preference to Younger Patients, http://www.amednews.com/article/20110328/profession/303289943/7/ (March 28, 2011); Neurology on Demand, The New Kidney Allocation System, https://storify.com/nephondemand/the-new-kidney-transplant-allocation-system (Accessed 2014); Video, The Kidney Allocation System, What Candidates Need to Know, http://vimeo.com/107481347 (Accessed 2014).
 
 
[x] O’Reilly, Kidney transplant plan would give preference to younger patients, http://www.amednews.com/article/20110328/profession/303289943/7/ (March 28, 2011).
 
[xi] Id. 
 
[xii] Id.
 
[xiii] Id. 
 
[xiv] Id.  See Also: Benjamin E. Hippen, M.D., J. Richard Thistlethwaite, Jr., M.D., Ph.D., and Lainie Friedman Ross, M.D., Ph.D., Risk, Prognosis, and Unintended Consequences in Kidney Allocation (April 7, 2011)(“ The intuitive appeal of a proposal to maximize the overall survival of patients after kidney transplantation is obvious. However,
a significant change in allocation policy must be based on good data and sound methods of data analysis. As Ware has pointed out, the use of risk factors as prognostic tools for the purpose of prospective individual risk stratification often yields disappointing results.2 This is because much depends on how various risk factors in donors and recipients are distributed across sample populations that do or do not have graft loss. If a single
risk factor — or an elaborate combination of donor and recipient factors such as those captured in the KDPI and EPTS score is distributed substantially similarly in the population of patients whose grafts survive and in the population of those who experience graft loss, then a model that uses it to distinguish graft survival from early graft failure will have low sensitivity in making predictions regarding individual donor kidneys (in the
case of the KDPI) or individual candidates (in the case of the EPTS score). Any attempt to increase
sensitivity in the model will yield an unacceptably high frequency of false positives.3”)(“ To ensure a fair allocation system, the goal of maximizing benefit must be balanced by concerns about equity (fair opportunity
for everyone with end-stage renal disease). In the absence of reliable and reproducible prognostic tools for estimating graft survival, and without a clear understanding of the unintended consequences of a substantial change in allocation policy on trends in living donation, discussing what a fair allocation policy should look
like is putting the cart before the horse.”).
 
 
[xv] Video, The Kidney Allocation System, What Candidates Need to Know, http://vimeo.com/107481347 (Accessed 2014).
 
 
[xvi] Id. 
 
[xvii] Neurology on Demand, The New Kidney Allocation System, https://storify.com/nephondemand/the-new-kidney-transplant-allocation-system (Accessed 2014).
 
 
[xviii] Id.
 
 
[xix] Video, The Kidney Allocation System, What Candidates Need to Know, http://vimeo.com/107481347 (Accessed 2014).
 
 
[xx] Id.
 
 
[xxi] Id.
 
[xxii] Talking About Transplantation, Question And Answers for Kidney Transplant Candidates About Kidney Allocation, http://www.unos.org/docs/Kidney_Brochure.pdf (Accessed 2014).
 
[xxiii] Id.
 
 
[xxiv] Id.
 
 
[xxv] Video, The Kidney Allocation System, What Candidates Need to Know, http://vimeo.com/107481347 (Accessed 2014).
 
 
[xxvi] Neurology on Demand, The New Kidney Allocation System, https://storify.com/nephondemand/the-new-kidney-transplant-allocation-system (Accessed 2014).
 
 
[xxvii] Neurology on Demand, The New Kidney Allocation System, https://storify.com/nephondemand/the-new-kidney-transplant-allocation-system (Accessed 2014); Video, The Kidney Allocation System, What Candidates Need to Know, http://vimeo.com/107481347 (Accessed 2014).
 
 
 
 
 
[xxix] Id.  Neurology on Demand, The New Kidney Allocation System, https://storify.com/nephondemand/the-new-kidney-transplant-allocation-system (Accessed 2014)
 
 
[xxx] http://optn.transplant.hrsa.gov/converge/resources/allocationcalculators.asp?index=81 (Accessed 2014).  (This is a KDPI calculator so you can calculate you KDPI.  According to Indiana University, my KDPI is 44.
 
[xxxi] Video, The Kidney Allocation System, What Candidates Need to Know, http://vimeo.com/107481347 (Accessed 2014).
 
 
[xxxii] Id.
 
 
[xxxiii]  Video, The Kidney Allocation System, What Candidates Need to Know, http://vimeo.com/107481347 (Accessed 2014).
 
 
 
[xxxiv] Id.  See letter dated November 3, 2014 from Indiana University Health offering a consent to an 85% KDPI kidney.
 
 
 
 
 
 
 
[xxxvi] Video, The Kidney Allocation System, What Candidates Need to Know, http://vimeo.com/107481347 (Accessed 2014).
 
 
[xxxvii] Id. (“The actual graft survival for any donor kidney is dependent on patient-specific factors:
 
I.              Age
Ii.             Diagnosis
Iii.            HLA mismatching(http://www.uptodate.com/contents/hla-matching-and-graft-survival-in-kidney-transplantation)
(hemophagocytic lymphohistiocytosis (HLH) is an aggressive and life-threatening syndrome of excessive immune activation, http://www.uptodate.com/contents/clinical-features-and-diagnosis-of-hemophagocytic-lymphohistiocytosis)
 
Iv.            Compliance with treatment protocols
V.             Other factors
Vi.            The transplant team can determine the best options for the patient.”).
 
 
[xxxviii] Video, The Kidney Allocation System, What Candidates Need to Know, http://vimeo.com/107481347 (Accessed 2014).
 
 
[xxxix] Id.
 
 
[xl] Id.
 
 
[xli] Id.
 
 
[xlii] Id.
 
 
[xliii] Id.
 
 
[xliv] Id.
 
 
[xlv] Id.
 
 
[xlvi] Id.
 
[xlvii] Id.
 
 
 
 
[xlix] Id.
 
 
[l] Id.
 
 
[li] Id.
 
 
[lii] Id.
 
 
[liii] Id.
 
 
[liv] Id.
 
[lv] Ajay K. Israni,  Nicholas Salkowski,  Sally Gustafson,  Jon J. Snyder,  John J. Friedewald,  Richard N. Formica‖, Xinyue Wang, Eugene Shteyn,  Wida Cherikh,  Darren Stewart,  Ciara J. Samana,  Adrine Chung, Allyson Hart and
 Bertram L. Kasiske, New National Allocation Policy for Deceased Donor Kidneys in the United States and Possible Effect on Patient Outcomes, http://jasn.asnjournals.org/content/early/2014/05/14/ASN.2013070784.abstract (December 19, 2013).
 
[lvi] Id.

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