We expected that the most recent extension of Medicare immunosuppressant coverage would increase waitlisting among older/disabled beneficiaries who would always have insurance coverage for immunosuppressants, but would decrease waitlisting among younger/non-disabled beneficiaries who might not be able to afford their medications when Medicare eligibility ended at 3
years post transplant. After accounting for existing secular trends in waitlisting in a large national database, we found that the policy change did not appear to affect the already increasing access to the kidney transplant waitlist for the older/disabled beneficiaries, but did appear to decrease access for the younger/non-disabled beneficiaries.
While there is no absolute limit to the number of candidates who can be placed on the kidney transplant waitlist, the waitlist is restricted to those candidates transplant centers deem appropriate to receive the limited supply of transplantable organs. Historically, older kidney transplant candidates and those with extra-renal co-morbidities have been considered less ideal transplantation candidates, due to presumed reduced post-transplant functioning and survival [11
]. Because transplant recipients who are unable to afford their medications are at increased risk of medication noncompliance and subsequent graft loss [6
], it is conceivable that the extension of lifetime immunosuppressant coverage to ≥65/disabled Medicare beneficiaries would improve this group’s transplant candidacy appeal but would lessen that of younger/non-disabled patients with limited drug coverage, despite generally better overall health status. In other words, in anticipation of which patients will best care for the limited pool of deceased donor kidneys, transplant programs may be more inclined to waitlist older/disabled Medicare beneficiaries since the implementation of lifetime immunosuppressant coverage, but less inclined to waitlist the younger/non-disabled candidates who would lose Medicare coverage 3
years after transplant. Our findings of decreased waitlisting among the younger/non-disabled group after the policy change and increasingly lower likelihood of waitlisting with lower area income category support this assertion. This assertion is further supported by a recent study finding that most (67.3%) U.S. transplant programs report that they frequently or occasionally do not waitlist patients who are perceived to be unable to afford their immunosuppressant medications [30
Historically, the explicit rationale for differentiating between those with and without existing Medicare eligibility was that those under age 65 and disabled only because of ESRD were expected to return to work because successful transplant was considered ‘rehabilitation’ [31
]. However, return to work is uncommon post-transplant, especially among recipients not working prior to transplant, due to functional limitations and poor health status [32
]; and finding work that provides private insurance is even less common [34
Further, legislation for immunosuppressant coverage was established when post-transplant drugs were considered by some to be experimental, and 1-year graft survival was only 40% [35
]. Now that renal transplant 5-year survival is upward of 80% and is associated with better quality of life than dialysis, transplantation has become the preferred treatment for ESRD [36
]. Several studies have shown that, despite the significant cost of transplantation itself, post-transplant care and immunosuppressants, transplantation is more cost-effective than dialysis [5
]. While Medicare spends a total of $73,008 and $53,446 per patient year of hemodialysis and peritoneal dialysis, respectively, only $24,572 per patient year is spent on kidney transplant [37
]. Because Medicare resumes dialysis payments after transplant graft failure---which may be precipitated by limited coverage for immunosuppressant medications---current policy may be creating greater expense for the Medicare program through excess return to dialysis among <65/non-disabled patients. Our findings should be considered within the context of cost-effectiveness for the Medicare program, the primary payer for dialysis and transplantation in this country, and as part of the ongoing health care reform debate.
Because racial/ethnic minority ESRD patients are disproportionately younger and non-disabled than non-Hispanic whites, minorities may more often suffer decreased access under current policy. We found that non-Hispanic blacks in particular (but not other minorities) were less likely to be waitlisted than non-Hispanic whites. As evidenced in our study, racial/ethnic minorities are more likely to develop ESRD at a younger age than their non-Hispanic white counterparts [38
] and are therefore further from aging into Medicare eligibility.
Our study is not without limitations. Disability status was determined from the employment status variable. Information regarding underlying cause of disability was not available. Therefore, we were not able to differentiate between disability status due to ESRD and disability for another reason, which may have significantly inflated proportions truly eligible for unlimited immunosuppressant coverage fulfilled by the criterion disability not due to ESRD. This misclassification may have been most pronounced among minority patients given their younger age at ESRD onset, increasing the likelihood that their disability was ESRD-related. However, the likely effect of this misclassification would be to attenuate the observed relationship between policy change and the likelihood of waitlisting among ≥65/disabled versus <65/non-disabled patients. Thus, the true impact of the policy on access to transplantation may be underestimated. Additionally, some patients may have obtained private insurance after 90
days of initiating dialysis (when we defined insurance status); however, we expect this is very low in our 12-month observation period given the “pre-existing condition” of end-stage renal disease, which likely excluded many patients at that time from affordable private insurance plans.
It is also possible that factors other than the policy change are also contributing to the observed trends in waitlisting of the ≥65/disabled population compared to the <65/non-disabled population. For example, provider attitudes regarding an upper age limit for transplantation could have changed over time in favor of older applicants, independent of the availability of lifetime immunosuppressant coverage. Also, the implementation of policy for acceptance of expanded criteria donor (ECD) kidneys in late 2002 may have also played a partial role in observed rates [41
]; however, there was only a 15% increase in the number of ECD transplants [42
] during this study period, and not all ECD kidneys go to the ≥65/disabled population [43
]. Anticipation of the policy change could also be contributing to the steady increase over time in likelihood of waitlisting for the ≥65/disabled group---a finding that may reflect increasing patient and provider awareness of the policy and its ramifications. Such possibilities could not be examined here, given the limitations of the data, but future studies examining more recent trends in waitlisting, as well as reasons for waitlisting or not waitlisting potential transplant candidates, may help elucidate underlying causes.
Lastly, we recognize that waitlisting is but one step in access to kidney transplantation. Many factors, such as blood type and pre-formed antibodies, are important determinants of receiving a kidney transplant. Because these factors are only routinely measured in waitlisted candidates, they were largely missing in our dataset, rendering us unable to test our hypothesis in the entire ESRD population.