Department of Radiology, University of California Davis Medical Center, Sacramento, California.
University of California Davis School of Medicine, Sacramento, California.
J Am Coll Radiol. 2018 Apr;15(4):594-600. doi: 10.1016/j.jacr.2017.12.001.
To assess the impact of California's Breast Density Law (BDL) on MRI utilization and clinician ordering practices.
Our institutional review board approved this study that retrospectively compared the ordering pattern for screening breast MRI examinations in the 30-month period before and after the BDL was enacted. Examinations were subcategorized into those with breast density mentioned as an examination indication. Patients were classified into (1) high risk; (2) above average risk, defined but not quantified; and (3) undefined or average risk. χ test or Fisher's exact test was used to compare MRI utilization, use of breast density as an indication, patient demographics, and provider characteristics.
Screening MRI examinations with breast density as the indication increased from 8.5% (32 of 376) to 21.1% (136 of 646, P < .0001) after BDL. When high-risk patients were excluded, the increase was from 8% to 17.2% (P < .0001). Patient demographics before and after BDL were, by race: white 71.8% versus 71.2%; Asian 6.4% versus 10.5%; black 3.7% versus 3.1%; American Indian 0.3% versus 1.4%; Native Hawaiian or Pacific Islander 1.6% versus 1.7%; by ethnicity: Hispanic or Latino 10.6% versus 7.9%. Before and after BDL, predominantly female providers (81.4% and 77.4%, P = not significant [NS]) and specialists (62.5% and 63.5%, P = NS) ordered the majority of breast MRI examinations compared with males (18.6% and 22.6%, P = NS).
Screening breast MRI utilization for non-high-risk women more than doubled after the California BDL went into effect. BDL has had an impact on MRI utilization, and its clinical value for changing outcomes deserves further study.
评估加利福尼亚州乳房密度法（BDL）对 MRI 利用率和临床医生订购实践的影响。
我们的机构审查委员会批准了这项研究，该研究回顾性比较了 BDL 颁布前后 30 个月内筛查性乳房 MRI 检查的订购模式。检查分为提到乳房密度作为检查指征的检查。患者分为（1）高风险；（2）高于平均风险，定义但未量化；和（3）未定义或平均风险。使用 χ 检验或 Fisher's 确切检验比较 MRI 利用率、使用乳房密度作为指征、患者人口统计学和提供者特征。
BDL 后，以乳房密度为指征的筛查性 MRI 检查从 8.5%（376 例中的 32 例）增加到 21.1%（646 例中的 136 例，P<.0001）。排除高风险患者后，增加了 8%至 17.2%（P<.0001）。BDL 前后的患者人口统计学数据为：白人 71.8%比 71.2%；亚洲人 6.4%比 10.5%；黑人 3.7%比 3.1%；美国印第安人 0.3%比 1.4%；夏威夷原住民或太平洋岛民 1.6%比 1.7%；按族裔：西班牙裔或拉丁裔 10.6%比 7.9%。BDL 前后，以女性为主的提供者（81.4%和 77.4%，P=无显著意义[NS]）和专家（62.5%和 63.5%，P=NS）比男性（18.6%和 22.6%，P=NS）更常订购大多数乳房 MRI 检查。
加利福尼亚州 BDL 生效后，非高风险女性的筛查性乳房 MRI 利用率增加了一倍多。BDL 对 MRI 利用率产生了影响，其对改变结果的临床价值值得进一步研究。
