The implications of acute rejection and reduced allograft function on health care expenditures in contemporary US kidney transplantation.

Background: The economic ramifications of acute rejection (AR) are not well characterized in a contemporary population of kidney transplant recipients.

Methods: Data for Medicare-insured transplant recipients in 2000 to 2007 (n=45,250) were drawn from the United States Renal Data System. AR events were ascertained from the Organ Procurement and Transplantation Network reports covering months 0 to 12 (yr1), 13 to 24 (yr2), and 25 to 36 (yr3) after transplantation. AR was subclassified as antibody (Ab)-treated AR or other management (non-Ab-treated AR). The marginal cost impact of AR events during and before a period of interest was quantified by multivariate linear regression including covariates for recipient, donor, and transplant factors.

Results: Among recipients of standard criteria donor allografts, both Ab-treated AR events (yr1, $22,407; yr 2, $18,803; yr3, $13,909) and non-Ab-treated AR events (yr1, $14,122; yr2, $7852; yr3, $8234) were associated with significant increases in the cost of care. Patterns were similar among recipients of living donor and expanded criteria donor transplants. After weighting by population frequency, AR accounted for 2.3% to 3.8% of total costs incurred during 1 year of posttransplantation care. Subanalysis of recipients with yr1 estimated glomerular filtration rate (eGFR) information demonstrated markedly stronger cost variation across eGFR levels. For example, among those with non-Ab-treated AR, adjusted total yr2 costs were $22,747 with eGFR of 60 mL/min/1.73 m or higher but $43,881 with eGFR of 30 mL/min/1.73 m or lower.

Conclusions: AR is a significant contributor to individual posttransplantation costs. However, because of its low frequency, AR accounts for a small proportion of posttransplantation costs in the population. Healthcare costs in patients with AR are markedly higher among those with reduced compared with preserved allograft function.