Purpose: Variability in dialysis facility-level kidney transplant (KTx) rates have been reported, but little is known about KTx referral rates by dialysis facilities. No studies have been able to accurately measure regional KTx referral rates at the dialysis facility level, since either participation of all dialysis facilities or coordination with all transplant centers in a region is needed for an accurate referral count. The purpose of this abstract is to describe a new quality measure — the standardized referral ratio (SRR) — to estimate KTx referral rates among dialysis facilities in a region.

Methods: A two-stage Cox model stratified by facility and adjusting for relevant covariates can be used to calculate SRRs for each dialysis facility in a region. Stage one allows baseline KTx referral rates to vary between facilities. The stage two Cox model uses the linear value of the predictor variables in stage one for each patient to calculate a baseline referral rate. Martingale residuals in the second stage of the Cox model can be used to obtain the difference between observed and expected events for each subject. The SRR is calculated as a ratio of the sum of all expected referrals in a facility to the total number of observed referrals in a facility. In addition to SRRs, 95% Confidence Intervals can be calculated for each dialysis facility to account for the variability in the SRR estimates.

Results: The interpretation of the SRR is that for SRRs of 1.0, the observed KTx referral rate at the dialysis facility is equal to the expected transplant referral rate. SRRs < 1.0 indicate that the observed KTx referral rate is less than expected and SRRs > 1.0 indicate that the observed KTx referral rate is greater than expected, based on the regional average. Mathematical computation of this metric requires participation of all Ktx centers within a region for valid calculations of referral; multivariable adjustment may vary depending on region.

Conclusion: In collaboration with ESRD Network 6 and all KTx centers in Georgia, patient-level KTx referral data is currently underway. ESRD Network 6 plans to use SRRs as a quality indicator to identify poorly performing dialysis facilities in need of quality improvement interventions to improve KTx referral. Establishing the feasibility of measuring this novel health indicator may help launch a surveillance systems to regularly measure KTx referral.

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