Kidney transplant Medicare payments and length of stay: associations with comorbidities and organ quality

INTRODUCTION: We investigated associations between pre-transplant comorbidities, length of stay (LOS) and Medicare payments for transplant hospitalization. MATERIAL AND METHODS: We examined United States Renal Data System for 24,963 recipients of first deceased-donor kidney transplants in 1995-2002 for whom Medicare was the primary payer for at least a year pre-transplant. Pre-transplant ICD-9-CM codes from claims were classified with the Charlson and Elixhauser algorithms. Regression models for payments and LOS included: 1) baseline recipient, donor and transplant factors from the Organ Procurement and Transplant Network (OPTN), 2) OPTN variables and individual comorbidities and 3) OPTN variables and counts of Charlson or Elixhauser comorbidities. RESULTS: Factors most strongly associated with LOS were type I diabetes, cold ischemia time > 36 h, expanded criteria donor (ECD) and donation after cardiac death (DCD). Except for ECD, each was associated with increased payments. Upper respiratory disease, liver disease, peptic ulcer disease, diabetes, cancer and other diseases were also associated with increased LOS and payments. Each additional Charlson comorbidity increased LOS by 2.94% and payments by $471 (Elixhauser results: 1.71% for LOS, $277 for payments). Use of ECD or DCD organs were associated with 10-15% higher LOS and 5% increased Medicare payments for DCD. CONCLUSIONS: This methodology could be used to explore if Medicare reimbursement for transplantation of higher-risk recipients and using non-standard organs is financially adequate and to analyze related questions in other healthcare systems.