Center Volume and Kidney Transplant Outcomes in Pediatric Patients

Abstract

Rationale & objectives: Recent data demonstrate that center volume is not a factor in the outcomes of adult kidney transplant recipients. This study assessed whether center volume affects graft survival in pediatric patients who received a kidney transplant.

Study design: Case-cohort study.

Setting & participants: Kidney transplantation centers, recipients younger than 18 years.

Results: Data were retrieved from the Scientific Registry of Transplant Recipients for transplantations performed July 1, 2010, to June 30, 2015, and the Organ Procurement and Transplantation Network for transplantations performed January 1, 2010, to December 30, 2015. Center volume was divided into 3 groups: low (<4 per year), intermediate (4-8 per year), and high (>8 per year). The primary outcome was 3-year graft survival rate. Outcomes were reviewed in 115 centers that performed 3,762 transplantations. There were no substantive differences in sex, age, ethnicity, diagnosis, and kidney donor profile index score in the 3 transplantation center volume categories. During the 5-year period (July 1, 2010, to June 30, 2015), 3-year graft survival in centers with low, intermediate, and high volumes were 88.4%, 90.3%, and 92.1%, respectively; P = 0.02. Although outcomes for deceased donor kidney recipients were similar in the 3 volume categories, outcomes in patients who received a living kidney donation were better in the high-volume centers. Low household income was associated with poorer outcomes. However, 3-year graft survival was similar in the 3 center volume categories in high and low mean household income states.

Limitations: Lack of information for complications and individual family household income of recipients.

Conclusions: Transplantation outcomes are worse in pediatric patients treated at lower-volume centers. The difference was more pronounced for patients receiving living versus deceased donor kidneys. The distribution of household income in pediatric transplant recipients may also be a factor that contributes to lower 3-year graft survival in low-volume centers.

Keywords: Kidney transplant; center volume; deceased donation; household income; living donation; pediatric.

Graphical abstract

Figure 1

Graft survival for centers by volume for (A) period 1 (July 1, 2010, to December 31, 2012), (B) period 2 (January 1, 2013, to June 30, 2015), and (C) combined 5-year period (July 1, 2010, to June 30, 2015). Graphs illustrate graft survival at 1 month and 1 and 3 years after surgery in patients receiving a kidney transplant at low- (blue), intermediate- (orange), and high-volume (gray) centers. Numbers above columns indicate number of patients. (A) ∗P = 0.01; (C) ∗P = 0.02.

Figure 2

Graft survival for low- and high-volume center extremes. This graph illustrates graft survival at 1 month and 1 and 3 years after surgery in patients receiving a kidney transplant at extreme low- (blue) and high-volume (orange) centers. Numbers above columns indicate number of patients. ∗P = 0.003.

Figure 3

Living versus deceased donor graft survival. This graph illustrates graft survival at 1 month and 1 and 3 years after surgery in patients receiving a kidney transplant at low- (blue), intermediate- (orange), and high-volume (gray) centers. Solid bars represent graft survival from living donors, and striped bars represent graft survival from deceased donors. Numbers above columns indicate the number of patients. ∗P = 0.0002.

Figure 4

Graft survival in high- versus low-income states. This graph illustrates graft survival at 1 month and 1 and 3 years after surgery in patients receiving a kidney transplant at low- (blue) and high-income (orange) centers in states categorized by mean household income. Numbers above the columns indicate the number of patients. ∗P = 0.008; ∗∗P < 0.00001.

Figure 5

Graft survival in high- versus low-income states by center volume. This graph illustrates graft survival at 1 month and 1 and 3 years after surgery in patients receiving a kidney transplant at low- (blue), intermediate- (orange), and high-volume (grey) centers in states categorized by mean household income. Solid bars represent graft survival from high-income states, and striped bars represent graft survival from low-income states. Numbers above columns indicate number of patients.

Figure 6

Graft survival in high- and low-income states matched for state size. This graph illustrates graft survival at 1 month and 1 and 3 years after surgery in patients receiving a kidney transplant at low- (blue) and high-income (orange) centers in states categorized by mean household income but matched for area. Numbers above columns indicate number of patients. ∗P = 0.0035.

Figure 7

Graft survival in high- and low-income states matched for state size, by center volume. This graph illustrates graft survival at 1 month and 1 and 3 years after surgery in patients receiving a kidney transplant at low- (blue), intermediate- (orange), and high-volume (grey) centers in states categorized by mean household income but matched for area. Solid bars represent graft survival from high-income states, and striped bars represent graft survival from low-income states. Numbers above columns indicate number of patients.