Ten-year cost effectiveness of alternative immunosuppression regimens in cadaveric renal transplantation

Changing treatment protocol from azathioprine to mycophenolate mofetil: decrease in renal dysfunction, increase in infections

INTRODUCTION

Immunosuppression for renal transplantation has shifted from azathioprine (AZA) regimens to those containing mycophenolate mofetil (MMF). This study investigated the impact of this change on the causes for rehospitalization as well as on graft and patient survival.

METHODS

In this retrospective cohort study, we reviewed long-term patient and graft survivals as well as the causes of posttransplant admissions for 893 kidney recipients. Data on survival and readmissions were available for 811 subjects, who were divided to into the AZA cohort (n=289, transplantation between 1998 and 1999) and the MMF cohort (n=567, transplantation between 2000 and 2001). Survival, the cause for readmission, time interval between transplantation and readmission, intensive care unit (ICU) admission, mortality, and graft loss were compared between the two cohorts.

RESULTS

Five-year patient and graft survival rates were 85% and 67% for the AZA cohort and 91% and 68% for the MMF cohort (P=.013). There were 202 (71%) and 371 (72%) readmissions registered for the AZA and MMF groups, respectively. In comparison with the AZA cohort, while readmissions secondary to graft rejection showed a significant decrease in the MMF cohort (62% vs 35%, P=.000), readmissions secondary to infections exhibited a significant increase (37% vs 50%, P=.002). A marginally significant increased mortality rate (2% vs 5%, P=.087) and ICU admission rate (3% vs 6%, P=.062) were also observed in the MMF cohort by comparison with the AZA cohort.

CONCLUSION

The shift in the immunosuppression protocol from AZA to MMF, albeit advantageous in many instances, can sometimes undermine the outcome by giving rise to such complications as high infection rates.

Effect of New Immunosuppressive Regimens on Cost of Renal Transplant Maintenance Immunosuppression

Although newer immunosuppressive drugs control acute rejection better and have short-term economic advantages, their long-term cost-effectiveness is unknown. We studied the frequency with which different maintenance immunosuppression regimens were used in 3 renal transplantation cohorts treated in 1990, 1994, and 1998 (total number, 3279). We calculated the mean annual immunosuppressive costs based on the true costs in a medium-sized hospital. Cyclosporine, with or without azathioprine, was used almost exclusively as the initial maintenance immunosuppressive therapy in 1990-1994. In 1998, 65% of patients received mycophenolate mofetil (MMF), and 20% received tacrolimus (Tac). A growing number of patients from 1990-1994 were converted to MMF (12%-17%) and Tac (4%-8%), while treatment of those from the 1998 cohort remained stable. According to year 2000 costs, the mean immunosuppressive cost at 1 year in 1998 (5380 euros) was almost twice that of 1994 (2902 euros) or 1990 (2855 euros). In these 2 groups the mean cost was stable until 1996, then increased faster in the 1994 cohort (24.8%) than in the 1990 cohort (17.3%), although it remained significantly lower than that in 1998. Correction of the evolution of drug prices and the purchasing value of the peseta greatly absorbed these changes. The MMF and Tac regimens showed greater mean graft life, but without reaching statistical significance in a multivariate study. The introduction of new immunosuppressive drugs has had an important economic effect since 1996; its cost-effectiveness is still pending confirmation in Spain.

Lack of economic benefit with basiliximab induction in living related donor adult renal transplant recipients

STUDY OBJECTIVE

To assess the effect of basiliximab (BAS) induction therapy on acute rejection rates and overall costs in adult living related donor (LRD) renal transplant recipients. Design. Retrospective chart review and cost-effectiveness analysis of the first 12 months after transplantation.

SETTING

University hospital and outpatient renal transplant clinic.

PATIENTS

Sixty consecutive adult LRD renal transplant recipients.

INTERVENTION

The treatment group received BAS 20 mg intravenously on postoperative days 0 and 4. The control group received no induction agents. Both groups received cyclosporine microemulsion, azathioprine, and corticosteroids for maintenance immunosuppression.

MEASUREMENTS AND MAIN RESULTS

Six patients (three in each group) were excluded; three had received muromonab-CD3 as an induction agent and three were lost to follow-up. At 12-months, the frequency of acute rejection episodes was 15% (4/27) in the control group and 22% (6/27) in the BAS group (NS). Renal function, as measured by average serum creatinine level, was similar at months 1, 2, 3, 6, and 12 for both groups. The frequency of infectious complications was similar in both groups. No adverse effects were associated with BAS. Mean initial hospitalization charges were dollar 51,970.01 and dollar 68,093.90 in the control and BAS groups, respectively (p < 0.05). The control group had more readmissions (18 vs 14 in the BAS group), but the average charge/readmission was lower (dollar 10,148.50 vs dollar 21,952.58 in the BAS group; NS). All costs were adjusted to 2000 dollars (US).

CONCLUSION

Basiliximab induction therapy did not provide clear clinical efficacy benefit or prove to be cost-effective compared with no induction in LRD recipients.

Pharmacoeconomics of therapeutic drug monitoring in transplantation

Immunosuppressive drugs have contributed significantly to the success of organ transplantation. Therapeutic drug monitoring is an integral part of transplant protocols. However, there is little information concerning its positive contribution to pharmacoeconomics. Before developing studies to demonstrate the potential benefits of TDM, consideration must be given to the type of TDM to be evaluated. It is argued that, given that the lymphocyte in the central compartment is the target for immunosuppressants, Area-Under-the-Curve monitoring may be a better reflection of control and toxicity than traditional trough monitoring.