The association between loss of Medicare, immunosuppressive medication use, and kidney transplant outcomes

Abstract

Kidney transplant recipients aged <65 years qualify for Medicare coverage, but coverage ends 3 years posttransplant. We determined the association between timing of Medicare loss and immunosuppressive medication fills and kidney allograft loss. Using data from the Scientific Registry of Transplant Recipients (SRTR), US Renal Data System, and Symphony pharmacy fill database, we analyzed 78 861 Medicare-covered, kidney-alone recipients aged <65 years, and assessed the timing of Medicare loss posttransplant: early (<3 years), on-time (at 3 years), or late (>3 years). Immunosuppressant use was measured as medication possession ratio (MPR). Allograft loss was assessed using SRTR data. MPR was lower for recipients with early or late Medicare loss compared with no coverage loss for all immunosuppressive medication types. For calcineurin inhibitors, early Medicare loss was associated with a 53% to 86% lower MPR. On-time Medicare loss was not associated with a lower MPR. When recipients were matched by age, posttransplant timing of Medicare loss, and donor risk, the hazard of allograft loss was 990% to 1630% higher after early Medicare loss, and 140% to 740% higher after late Medicare loss, with no difference in the hazard for on-time Medicare loss. Ensuring ongoing Medicare access before and after 3 years posttransplant could affect graft survival.

Keywords: Scientific Registry for Transplant Recipients (SRTR); clinical research/practice; insurance - public; kidney transplantation/nephrology.

FIGURE 1

Description of the analytic cohort

FIGURE 2

Cumulative incidences of potential outcomes after transplant. Only a recipient’s first event was included in the curves. The cohort included kidney-alone recipients on Medicare at transplant, aged younger than 65 years at transplant, who underwent transplant between January 1, 2008, and December 31, 2014

FIGURE 3

Association of the timing of Medicare loss and subsequent (A) calcineurin-inhibitor-specific and (B) antimetabolite-specific medication possession ratio in the Symphony database. The cohort included kidney-alone recipients with at least one fill in the Symphony database who were on Medicare at transplant, aged younger than 65 years at transplant, and who underwent transplant between January 1, 2008, and December 31, 2014