Breast Biopsy Rates and Market Dynamics: How Provider Environment Shaped Diagnostic Practice in 2023

Abstract Introduction Guidelines for breast cancer screening aim to increase early detection and survival. However diagnostic follow-up relies on provider discretion, leading to variability in subsequent care and total cost. We sought to identify factors correlated to market-level biopsy variability. Methods Commercial claims and physician data for 2023 were sourced from Definitive Healthcare databases. Utilization rates were regressed on and adjusted for demographics in each Hospital Referral Region (HRR). HRRs were then categorized along three distinct axes: (1) degree of risk-sharing, (2) commonality of in-house diagnostics and (3) degree of academic-influence. Results While demographic factors account for screening differences, there remained much geographic variance in demographics-adjusted biopsy utilization, even for similar breast resection rates (indicative of true-positives). However, markets dominated by risk-sharing practices had lower biopsy rates (-0.4%, p=0.01), while those where screening, biopsy, and resection occur within the same provider system had higher rates (+0.9%, p<0.01). Similarly, biopsy rates were elevated in markets with academic medical centers and NCI-designated cancer centers (+0.6%, p=0.02). Conclusion These findings suggest provider-environment—both financial and cultural—affects market-level biopsy rate. The variation found indicates biopsy-overutilization is a non-zero factor in the cost of breast-cancer detection, underscoring the importance of consistent standards in mammogram-reading.