The cost of health care is rising, and this trend is also seen in transplantation. One particularly important complication of transplantation is rejection; however, the cost of rejection has not been quantified in a manner that is comprehensive, generalizable and based on standard of care. The purpose of this research project was to quantify the cost of processes of care (diagnosis and management), both inpatient and outpatient, of acute rejection events and associated complications in renal transplant recipients in a real-world US practice setting.
A retrospective matched case-control study was undertaken. A database of patients transplanted at The University Hospital, Cincinnati, Ohio, was analyzed to identify patients who had experienced a rejection episode. The same database was used to create a cohort of patients matched on age ± ten years, sex, ethnicity and type of transplant. There were 22 patients in each cohort. Data was collected for six months after the diagnosis of rejection, and the same time period post transplantation forward for six months in the matched controls. Costs were evaluated from the health-system perspective. Health-system costs were reported from the hospital cost accounting system and standardized to 2007 US dollars, outpatient medications were reported in average wholesale costs in 2009 dollars and outpatient clinic visit costs were derived from Medicare reimbursement, 2008 dollars.
The total costs were significantly different between the groups for six months of care. The mean cost of care for rejection patients was $51,765 ($14,291-137,021) versus no rejection patients $32,784 ($10,358-78,109), p = 0.004. Total health-system costs were also significantly different: $30,000 ($405-400,961) versus 11,460 ($260-84,954), rejection versus no rejection, respectively, (p = 0.029). It was expected that diagnostic costs would be higher in the rejection group, and this was consistent with the findings. Radiology costs were significantly higher in the case cohort: control $2,371 ($233-11,286) vs , $432 ($57-2,057) (p< 0.001). Pathology costs were also significantly higher in the rejection group: $822 ($124-3,264) vs $359 ($116-844), (p = 0.003). Additionally, monitoring was significantly higher over the six month period of time for rejection patients as compared to no rejection patients: $866 ($15-1,446) versus $264 ($27-6,633), (p = 0.006). Total medication costs were not significantly different between the two groups: rejection $28,517 ($4,437-118,291) vs no rejection $22,238 ($8,609-48,070), p=0.56.
In terms of resource utilization, more patients in the acute rejection group experienced hospitalization as compared to no rejection patients 19 (86%) versus 8 (35%), p=0.002. More rejection patients received care at the Transplant Ambulatory Care Unit as well. Additional monitoring also occurred in the rejection patients, laboratory monitoring, both inpatient and outpatient, as well as diagnostics including cultures, x-rays and ultrasounds.
As expected, there were significant differences in cost, as well as healthcare utilization, for patients who experienced an acute rejection event. The mean difference attributable to rejection is $18,981. This amount could be applied to future studies demonstrating rejection cost avoidance and cost- effectiveness analyses of new modalities that prevent, detect or treat rejection.