Variability in Partial Nephrectomy Outcomes: Does Your Surgeon Matter?

Background: Understanding physician-level discrepancies is increasingly a target of US healthcare reform for the delivery of quality-focused patient care. Objective: To estimate the relative contributions of patient and surgeon characteristics to the variability in key outcomes after partial nephrectomy (PN). Design, setting, and participants: Retrospective review of 1461 patients undergoing PN performed by 19 surgeons between 2011 and 2016 at a tertiary care referral center. Intervention: PN for a renal mass. Outcomes measurements and statistical analysis: Hierarchical linear and logistic regression models were built to determine the percentage variability contributed by fixed patient and surgeon factors on peri- and postoperative outcomes. Residual between- and within-surgeon variability was calculated while adjusting for fixed factors. Results and limitations: On null hierarchical models, there was significant betweensurgeon variability in operative time, estimated blood loss (EBL), ischemia time, excisional volume loss, length of stay, positive margins, Clavien complications, and 30-d readmission rate (all p < 0.001), but not chronic kidney disease upstaging (p = 0.47) or percentage preservation of glomerular filtration rate (p = 0.49). Patient factors explained 82% of the variability in excisional volume loss and 0-32% of the variability in the remainder of outcomes. Quantifiable surgeon factors explained modest amounts (10-40%) of variability in intraoperative outcomes, and noteworthy amounts of variability (90-100%) in margin rates and patient morbidity outcomes. Immeasurable surgeon factors explained the residual variability in operative time (27%), EBL (6%), and ischemia time (31%). Conclusions: There is significant between-surgeon variability in outcomes after PN, even after adjusting for patient characteristics. While renal functional outcomes are consistent across surgeons, measured and unmeasured surgeon factors account for 18100% of variability of the remaining peri- and postoperative variables. With the increasing utilization of value-based medicine, this has important implications for the goal of optimizing patient care. Patient summary: We reviewed our institutional database on partial nephrectomy performed for renal cancer. We found significant variability between surgeons for key outcomes after the intervention, even after adjusting for patient characteristics. (C) 2018 European Association of Urology. Published by Elsevier B.V. All rights reserved.