From the Department of Radiology, Division of Breast Imaging, Duke University Medical Center, Box 3808, Erwin Rd, Durham, NC 27710 (M. Bahl, J.A.B., S.V.G.); and American College of Radiology, Reston, Va (M. Bhargavan-Chatfield, E.K.B.).
Radiology. 2016 Sep;280(3):701-6. doi: 10.1148/radiol.2016152457. Epub 2016 Mar 28.
Purpose To evaluate the impact of breast density notification legislation on breast density reporting by radiologists nationally. Materials and Methods The institutional review board exempted this HIPAA-compliant retrospective study from the requirement for informed consent. State-level data over a 5-year period on breast density categorization and breast cancer detection rate were collected from the National Mammography Database (NMD). Z tests were used to calculate differences in proportions. Results Facilities in 13 of 17 states that had breast density notification legislation as of 2014 submitted data to the NMD before and after law enactment. A total of 1 333 541 mammographic studies (hereafter called "mammograms") over a 30-month period, beginning 20 months before and continuing 10 months after law enactment, were included in the analysis. There was a small but statistically significant decrease in the percentage of mammograms reported as showing dense breast tissue (hereafter called "dense mammograms") in the month before law enactment compared with the month after (43.0% [22 338 of 52 000] vs 40.0% [18 604 of 46 464], P < .001). There was no statistically significant difference in the percentage of mammograms reported as dense in the month before law enactment compared with the 10th month after (43.0% [22 338 of 52 000] vs 42.8% [15 835 of 36 991], P = .65). There were no significant differences in the breast cancer detection rate between the month before and the month after law enactment (3.9 vs 3.8 cancers per 1000 mammograms, P = .79) or between the month before law enactment and the 10th month after (3.9 vs 4.2 cancers per 1000 mammograms, P = .55). In 21 analyzed states without breast density notification legislation, the percentage of mammograms reported as dense did not decrease below 42.8% (43 363 of 101 394) from 2010 to 2014, in contrast to 13 analyzed states with breast density notification legislation, which reached a nadir of 39.3% (20 965 of 53 360) (P < .001). Conclusion The percentage of mammograms reported as dense slightly decreased immediately after enactment of breast density notification legislation but then returned to prelegislation percentages within 10 months. (©) RSNA, 2016.
目的 评估乳腺密度通知立法对全国放射科医生乳腺密度报告的影响。
材料与方法 本 HIPAA 合规性回顾性研究经机构审查委员会豁免知情同意书要求。在国家乳腺摄影数据库（NMD）中收集了 5 年期间关于乳腺密度分类和乳腺癌检出率的州级数据。使用 Z 检验计算比例差异。
结果 在截至 2014 年已有乳腺密度通知立法的 17 个州中的 13 个州，在该法颁布前后向 NMD 提交了数据。共纳入了 30 个月期间（从立法前 20 个月开始，持续 10 个月）的 1333541 例乳腺 X 线摄影研究（以下简称“乳腺 X 线摄影”）。与立法后相比，在立法前一个月，报告显示致密乳腺组织的乳腺 X 线摄影（以下简称“致密乳腺 X 线摄影”）百分比略有但具有统计学意义的下降（43.0%[22/52000]比 40.0%[18/46464]，P<.001）。与立法前 10 个月相比，立法前一个月报告的致密乳腺 X 线摄影百分比无统计学差异（43.0%[22/52000]比 42.8%[15/36991]，P=0.65）。在立法前后一个月（每 1000 例乳腺 X 线摄影 3.9 例与 3.8 例癌症，P=0.79）或立法前一个月与立法后 10 个月（每 1000 例乳腺 X 线摄影 3.9 例与 4.2 例癌症，P=0.55）之间，乳腺癌检出率无显著差异。在没有乳腺密度通知立法的 21 个分析州，从 2010 年到 2014 年，报告的致密乳腺 X 线摄影百分比未降至 42.8%（101394 例中的 43363 例）以下，而在有乳腺密度通知立法的 13 个分析州，这一比例降至 39.3%（53360 例中的 20965 例）（P<.001）。
结论 乳腺密度通知立法颁布后，报告的致密乳腺 X 线摄影百分比略有下降，但在 10 个月内恢复到立法前的百分比。
