Underutilization of Needle Biopsy Before Breast Surgery: A Measure of Low-Value Care

Background: Breast core needle biopsy (CNB) can obviate the need for breast surgery in patients with an unknown breast lesion; however, variation in compliance with this guideline may represent a disparity in health care and a surrogate measure of unnecessary surgery. We evaluated variation in breast CNB rates prior to initial breast cancer surgery. Methods: We performed a retrospective analysis using Medicare claims from 2015 to 2017 to evaluate the proportion of patients who received a CNB within 6 months prior to initial breast cancer surgery. Outlier practice pattern was defined as a preoperative CNB rate ≤ 70%. Logistic regression was used to evaluate surgeon characteristics associated with outlier practice pattern. Results: We identified 108,935 female patients who underwent initial breast cancer surgery performed by 3229 surgeons from July 2015 to June 2017. The mean CNB rate was 86.7%. A total of 7.7% of surgeons had a CNB performed prior to initial breast surgery ≤ 70% of the time, and 2.0% had a CNB performed ≤ 50% of the time. Outlier breast surgeons were associated with practicing in a micropolitan area (odds ratio [OR] 1.88, 95% confidence interval [CI] 1.29–2.73), in the South (OR 1.84, 95% CI 1.20–2.84) or West region (OR 1.78, 95% CI 1.11–2.86), > 20 years in practice (OR 1.52, 95% CI 1.09–2.11), and low breast cancer surgery volume (< 30 cases in the study period; OR 4.03, 95% CI 2.75–5.90). Conclusions: Marked variation exists in whether a breast core biopsy is performed prior to initial breast surgery, which may represent unnecessary surgery on individual patients. Providing surgeon-specific feedback on guideline compliance may reduce unwarranted variation.