Open Access Research article

Medicare immunosuppressant coverage and access to kidney transplantation: a retrospective national cohort study

Vanessa Grubbs1*, Laura C Plantinga2, Eric Vittinghoff3, Ann M O’Hare4 and R Adams Dudley5

Author Affiliations

1 Division of Nephrology, University of California San Francisco, San Francisco General Hospital, San Francisco, CA, USA

2 Department of Epidemiology, Emory University Rollins School of Public Health, Atlanta, GA, USA

3 Department of Epidemiology & Biostatistics, University of California San Francisco, San Francisco, CA, USA

4 University of Washington, Nephrology and Veterans Administration Puget Sound Healthcare System, Seattle, WA, USA

5 Pulmonary and Philip R. Lee Institute for Health Policy Studies, University of California San Francisco, San Francisco, CA, USA

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BMC Health Services Research 2012, 12:254  doi:10.1186/1472-6963-12-254

Published: 16 August 2012



In December 2000, Medicare eliminated time limitations in immunosuppressant coverage after kidney transplant for beneficiaries age ≥65 and those who were disabled. This change did not apply to younger non-disabled beneficiaries who qualified for Medicare only because of their end-stage renal disease (ESRD). We sought to examine access to waitlisting for kidney transplantation in a cohort spanning this policy change.


This was a retrospective cohort analysis of 241,150 Medicare beneficiaries in the United States Renal Data System who initiated chronic dialysis between 1/1/96 and 11/30/03. We fit interrupted time series Cox proportional hazard models to compare access to kidney transplant waitlist within 12 months of initiating chronic dialysis by age/disability status, accounting for secular trends.


Beneficiaries age <65 who were not disabled were less likely to be waitlisted after the policy change (hazard ratio (HR) for the later vs. earlier period, 0.93, p = 0.002), after adjusting for sociodemographic factors, co-morbid conditions, income, and ESRD network. There was no evidence of secular trend in this group (HR per year, 1.00, p = 0.989). Likelihood of being waitlisted among those age ≥65 or disabled increased steadily throughout the study period (HR per year, 1.04, p < 0.001), but was not clearly affected by the policy change (HR for the immediate effect of policy change, 0.93, p = 0.135).


The most recent extension in Medicare immunosuppressant coverage appears to have had little impact on the already increasing access to waitlisting among ≥65/ disabled beneficiaries eligible for the benefit but may have decreased access for younger, non-disabled beneficiaries who were not. The potential ramifications of policies on candidacy appeal for access to kidney transplantation should be considered.