Lack of Economic Benefit With Basiliximab Induction in Living Related Donor Adult Renal Transplant Recipients

Jason A. Crompton, Pharm.D., Troy Somerville, Pharm.D., Lonnie Smith, Pharm.D., Jacke Corbett, FNP-C, Edward Nelson, M.D., John Holman, M.D., Fuad S. Shihab, M.D.

Disclosures

Pharmacotherapy. 2003;23(4) 

In This Article

Methods

The study was approved by the institutional review board. We conducted a retrospective review of all LRD renal transplantations performed at our hospital from January 1997-May 2000. Due to perceived increases in acute rejection rates in our adult LRD renal transplant program, BAS induction was incorporated into our center's protocols in early 1999. The dosage was 20 mg intravenously on postoperative days 0 and 4. The treatment group consisted of patients receiving BAS; the historical control group consisted of patients from the period immediately before we began administering BAS. Both groups received triple-drug maintenance immunosuppression.

Six patients (three in each group) were excluded: three were lost to follow-up and three had received an induction agent other than BAS, muromonab-CD3. This left 27 patients in each group. Patients also were excluded if they had previously undergone two or more organ transplantations.

All patients received immunosuppressive therapy consisting of cyclosporine microemulsion and azathioprine beginning 3 days before scheduled transplantation. They also received intravenous methylprednisolone 500 mg intraoperatively, followed by 125 mg every 6 hours for three doses postoperatively. Post-transplantation therapy consisted of oral prednisone tapered over 18 months to a final dosage of 5 mg/day. Target cyclosporine whole blood trough levels (Abbott TDx; Abbott Laboratories, Abbott Park, IL) were 350-450 ng/ml at 0-3 months and 125-250 ng/ml at more than 3 months. Azathioprine was dosed at 2 mg/kg/day. Two haplotype matches did not receive azathioprine.

The primary end point of the study was acute cellular rejection at 12 months. Biopsies were graded using the Banff 97 working classification of renal allograft pathology.[19] Treatment for acute rejection consisted of high-dose corticosteroids ( > 500 mg of intravenous methylprednisolone) or rabbit antithymocyte globulin 1.5 mg/kg/day intravenously for 7-10 days for steroid-resistant rejections.

Secondary end points were graft and patient survival at 12 months, time to first rejection episode, steroid-resistant rejection, graft function as measured by serum creatinine level, delayed graft function, length and cost of initial hospitalization, types and frequencies of infections, cost of infection treatment, numbers and costs of readmissions, and frequency of malignancies. Delayed graft function was defined as the need for dialysis after transplantation.

Due to the time span between the beginning and end of the study, charges for both groups were adjusted to 2000 dollars (US) using the annual consumer price index (CPI) adjustment for inflation in the western United States.[20] Initial hospitalization and readmission charges were obtained from the hospital billing system database. Charges were those billed to patients' insurance carriers. Diagnosis-related group (DRG) payment data were obtained for readmissions. Adjustments for inflation were calculated with the following formula:

Year 2000 charge = year 1997-1999 charge
(year 2000 CPI/year 1997-1999 CPI)

Cost-effectiveness was measured with incremental cost-effectiveness ratios, defined as:

Charge (BAS group) - charge (control group)
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Outcome measure (BAS - control)

For example:

Initial hospitalization charge (BAS) -
initial hospitalization charge (control)
____________________________________

length of stay (BAS) - length of stay (control)
= charge for BAS/hospital day saved or gained

Costs for infectious episodes were based on drug costs. Drug costs were determined from published average wholesale prices.[21]

Continuous variables were reported as means, medians, standard deviations, and 95% confidence intervals. Categorical variables were reported as numbers and/or percentages of patients with the reported characteristic. For continuous variables, the two groups were compared using the independent samples t test for comparisons among all patients and the Mann-Whitney U test for subgroup analysis. The 2 test was used to analyze categorical variables. Statistical significance was defined as a p value less than or equal to 0.05. Statistical analysis was performed with Microsoft Excel 97 spreadsheet (Microsoft Corp., Redmond, WA) with Analyse-it General statistics add-on software, version 1.62 ((Analyse-it Software, Ltd., Leeds, United Kingdom).

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