Long-term evaluation of kidney biopsy outcomes to guide continuous quality improvement

Background Kidney biopsy is essential for diagnosis and management but carries bleeding risks. Efforts to reduce bleeding may compromise tissue adequacy, highlighting the need to systematically evaluate biopsy performance. Understanding factors that influence both safety and adequacy can guide targeted quality improvement (QI) efforts. Methods We conducted a retrospective single-center study of native kidney biopsies (2014–2023) as part of a QI initiative to improve biopsy safety and adequacy. Multivariable logistic regression identified factors associated with major complications (need for angiography, embolization, or transfusion within seven days of biopsy) and biopsy adequacy (≥ 10 glomeruli for light microscopy and ≥ 1 glomerulus for indirect immunofluorescence and electron microscopy). Results A total of 796 biopsies were analyzed (56.2% female; median age 54.9 years; median BMI 28.9 kg/m²). An 18-gauge needle was used in 98% of biopsies. Major complications occurred in 10.3%, improving from 14.5% in 2014 to 2.8% in 2023 following prior QI interventions. Biopsy adequacy was achieved in 58.4%. Higher hemoglobin (adjusted odds ratio (aOR) 0.73, 95% CI 0.60–0.90) and platelet count (aOR 0.88, 95% CI 0.79-1.00) were associated with lower complications, whereas acute kidney injury (aOR 4.44 (95% CI 1.49–13.24), elevated INR (aOR 2.72 (95% CI 1.03–7.19) increased risk. Biopsy adequacy was higher with Radiologist #6 (aOR 2.59, 95% CI 1.47–4.55) and #4 (aOR 2.24, 95% CI 1.07–4.66), longer biopsy core length (aOR 2.13, 95% CI 1.53–2.98), and lower BMI (aOR 0.97, 95% CI 0.94–0.99). Conclusion This study will inform the design of multidisciplinary QI interventions to improve kidney biopsy adequacy and further reduce the complication rate. Planned interventions include peer discussions led by proceduralists with the best adequacy outcomes and a high-risk biopsy protocol. Though center-specific, these results emphasize the value of local data in improving biopsy safety and establishing benchmarks for future guidelines.