Income-Related Disparities in Kidney Transplant Graft Failures Are Eliminated by Medicare's Immunosuppression Coverage
- Presenter:
Chair: Carole Gresenz; Discussant: Will Dow Wed June 7, 2006 8:00-9:30 Room 235
RATIONALE: The maintenance immunosuppressive (IS) regimens required following kidney transplantation cost approximately $1,000 per month, a financial burden that is especially difficult for lower income transplant recipients. The changing durations of Medicare’s coverage of IS medications for kidney transplant recipients have provided opportunities to estimate the impact of that coverage on income-related disparities in the survival of the kidney graft. Previously published analyses of Medicare’s 1994 extension from 1 to 3 years IS coverage demonstrated that the extra two years eliminated a previously significant income-related disparity in the 2nd and 3rd years post-transplant. In 2000, Medicare extend the IS coverage to the life of the graft for the elderly and disabled.
OBJECTIVE: This study seeks to estimate the proportion of the annual graft losses in the fourth and fifth year post-transplant that may be correlated with the loss of Medicare’s Immunosuppression coverage at the end of three years post-transplant.
METHODOLOGY: The most recent USRDS data allow up to a five year follow-up for patients transplanted between January of 1997 and December of 1999. Among this cohort, income-related differences in graft survival among individuals eligible for only three years of IS coverage were compared with income-related difference among individuals eligible for life-time IS coverage. Of the 13,491first kidney transplanted from cadaveric donors whose transplant was primarily financed by Medicare, 3,943 had grafts that survived uncensored for 3 years and 90 days or more and who used Medicare’s IS coverage for 3 years. Median income of the ZIP code of the patient’s residence from the 2000 Census was used as a proxy patient income. Kaplan-Meier plots and multivariate Cox Proportional Hazard models were used to identify significant differences income-related disparities between the graft survival of patients who then did use and did not use Medicare’s IS coverage in the first 3 months of the 4th year.
RESULTS: Kaplan-Meier model estimates indicated that: i) loss of Medicare’s Insurance Coverage increased graft failures by 56.3% (P<0.01) among low income individuals with incomes too high for Medicaid, and ii) 12.3% of all graft failures in years 4 and 5 after transplant may be attributed to the loss of Medicare’s insurance coverage.
CONCLUSION: Medicare’s extensions of IS coverage have consistently eliminated the previously existing income-related disparities in kidney graft survival. Unfortunately, individuals who received a transplanted kidney primarily financed by Medicare, who are not disabled, and who were under 62 at transplantation remain eligible for only 3 years of Medicare’s IS coverage.
