Female breast cancer (FBC) incidence rate (IR) varies greatly across counties in the United States (U.S.). Factors contributing to these geographic disparities have not been fully understood at the population level. In this study, we investigated the relationships between the county-level FBC IR and a diverse set of variables in demographics, socioeconomics, life style, health care accessibility, and environment. Our study included 1,277 counties in the U.S. where the female population was 10,000 or above for at least one race/ethnicity. After controlling for the racial/ethnic and other significant factors, percent of husband-wife family households (pHWFH) for a racial/ethnic group in a county is negatively associated with FBC IR (p < 0.001). A 10% increase in married family households may lower a county's IR by 5.2 cases per 100,000 females per year. We also found that PM2.5 (fine inhalable particles with a diameter of 2.5 micrometers or less) is positively associated with FBC IR (p < 0.001). Counties with the highest level of PM2.5 have approximately 4 additional FBC new cases per 100,000 females per year than counties with the lowest level of PM2.5. Furthermore, we found that the county-level factors contributing to FBC IR vary significantly for different racial groups using race-specific models. While confirming most of the previously known patient- and neighborhood-level risk factors (such as race/ethnicity, income, and health care accessibility), our study identified two significant county-level factors contributing to the spatial disparity of FBC IR across the U.S. The newly-identified beneficial factor (marriage) and risk factor (PM2.5), together with the verified known factors, may help provide insights to officials of health departments/organizations for them to make decisions on cancer intervention strategies.

中文翻译：

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通过大规模人口研究确定县级女性乳腺癌发病率因素

美国 (US) 各县的女性乳腺癌 (FBC) 发病率 (IR) 差异很大。造成这些地理差异的因素在人口层面尚未得到充分了解。在这项研究中，我们调查了县级 FBC IR 与人口统计、社会经济学、生活方式、医疗保健可及性和环境等多种变量之间的关系。我们的研究包括美国 1,277 个县，其中至少一个种族/族裔的女性人口达到 10,000 人或以上。在控制种族/民族和其他重要因素后，一个县内某个种族/民族群体的夫妻家庭家庭百分比 (pHWFH) 与 FBC IR 呈负相关 (p < 0.001)。已婚家庭数量增加 10% 可能会使一个县的 IR 每年每 100,000 名女性降低 5.2 例。我们还发现 PM2.5（直径为 2.5 微米或更小的可吸入细颗粒）与 FBC IR 呈正相关 (p < 0.001)。PM2.5 水平最高的县每年每 100,000 名女性中 FBC 新病例比 PM2.5 水平最低的县多大约 4 例。此外，我们使用特定种族模型发现，对于不同种族群体，影响 FBC IR 的县级因素存在显着差异。在确认大多数先前已知的患者和社区层面的风险因素（例如种族/民族、收入和医疗保健可及性）的同时，我们的研究确定了导致美国 FBC IR 空间差异的两个重要县级因素新发现的有益因素（婚姻）和风险因素（PM2.5），加上经过验证的已知因素，可能有助于为卫生部门/组织的官员提供有关癌症干预策略决策的见解。