Presentation Authors: Douglas Cheung*, Toronto, Canada, Patrick Richard, Sherbrooke, Canada, Diana Magee, Toronto, Canada, Luke Lavallée, Ottawa, Canada, Frédéric Pouliot, Quebec City, Canada, Maria Komisarenko, Lisa Martin, Toronto, Canada, Jean-Baptiste Lattouf, Montreal, Canada, Shabbir Alibhai, Murray Krahn, Antonio Finelli, Toronto, Canada
Introduction: Despite strong safety and accuracy data, renal biopsy utilization remains low. Proponents of no-biopsy argue that &[Prime]it would not change management&[Prime] since biopsy cohorts used in existing studies may not be representative of those progressing to treatment._x000D_
In a multi-institutional nephrectomy (treatment) cohort, we performed a cost-effectiveness analysis of renal biopsy to alter management and save costs in patients who have (would have) undergone intervention.
Methods: We completed a decision analysis (Figure 1) populated by a multi-institutional, multi-provincial Canadian cohort from 2013 to 2015. Outcomes and costing data were compared against reference literature values for generalizability to other jurisdictions._x000D_
We completed probabilistic (Monte Carlo simulation, normal distributions) and deterministic sensitivity analyses for all model inputs across min-max published literature values. Non-diagnostic biopsies were re-biopsied once. Given our low event rate and risk of bias, literature rates were used for false negative and false positive rates within the model. TreeAgePro software was used.
Results: 542 patients were included: 192 (35%) received pre-operative biopsy and 58 (10.7%) had benign disease on nephrectomy pathology. 14 (7.3%) had discordant pathology between biopsy and nephrectomy; however, most of these would not have altered management (i.e. malignant disease misclassified between clear cell, papillary, chromophobe or oncocytic neoplasm NOS). 7 (3.6%) were non-diagnostic biopsies. Using final pathology as a gold standard and correcting for biopsy accuracy, we found a number needed to biopsy (NNTB) of 10.4 biopsies per nephrectomy avoided._x000D_
Results were most sensitive to parameter uncertainty around probability of benign disease, cost of surgery ($12 425), and of biopsy ($1 137). After 50 000 simulations, biopsy was cost saving ($11 933 vs $12 416, threshold 6.9% likelihood of pre-operative benign disease). In sub-analysis of non-biopsy centres only (16% benign disease), cost savings increased (biopsy $11 385) and NNTB fell to 7.0 biopsies per nephrectomy avoided.
Conclusions: Even prior to incorporating quality of life benefit from avoiding unnecessary operation and the cost of surgical complications, we demonstrate clinical and cost effectiveness of incorporating renal biopsy as a useful tool in pre-operative planning.