Krieger Nancy, Feldman Justin M, Kim Rockli, Waterman Pamela D
Department of Social and Behavioral Sciences, Harvard T.H. Chan School of Public Health, Boston, MA.
JNCI Cancer Spectr. 2018 Apr 25;2(1):pky009. doi: 10.1093/jncics/pky009. eCollection 2018 Jan.
The handful of studies (<30) on cancer and residential segregation have focused on racial segregation, primarily at the city/town level. We tested a priori hypotheses about choice of measure and level by extending use of the Index of Concentration at the Extremes (ICE) to quantify both economic and racial residential segregation, singly and combined, and conducted analyses for the total population and stratified by race/ethnicity.
Outcomes comprised Massachusetts incidence rates (2010-2014) for invasive breast, cervical, and lung cancer, analyzed in relation to census tract and city/town ICE measures for income, race/ethnicity, race/ethnicity + income, and the federal poverty line. Multilevel Poisson regression modeled observed counts of incident cases.
Both choice of metric and level mattered. As illustrated by cervical cancer, in models including both the census tract and city/town levels, the rate ratio for the worst to best quintile for the total population was greatest at the census tract level for the ICE for racialized economic segregation (3.0, 95% confidence interval [CI] = 2.1 to 4.3) and least for the poverty measure (1.9, 95% CI = 1.4 to 2.6), with null associations at the city/town level. In analogous models with both levels for lung cancer, however, for the non-Hispanic black and Hispanic populations, the rate ratios for, respectively, the ICE and poverty measures, were larger (and excluded 1) at the city/town compared with the census tract level.
Our study suggests that the ICE for racialized economic segregation, at multiple levels, can be used to improve monitoring and analysis of cancer inequities.
为数不多的关于癌症与居住隔离的研究（少于30项）聚焦于种族隔离，主要是在城市/城镇层面。我们通过扩展使用极端集中度指数（ICE）来检验关于测量方法和层面选择的先验假设，以单独和综合的方式量化经济和种族居住隔离，并对总人口以及按种族/族裔分层进行分析。
研究结果包括马萨诸塞州（2010 - 2014年）浸润性乳腺癌、宫颈癌和肺癌的发病率，分析时考虑了普查区以及城市/城镇层面关于收入、种族/族裔、种族/族裔 + 收入和联邦贫困线的ICE测量值。多水平泊松回归模型对观察到的发病病例数进行建模。
测量指标和层面的选择都很重要。以宫颈癌为例，在包含普查区和城市/城镇层面的模型中，对于总人口而言，从最差到最好五分位数的发病率比在普查区层面，种族化经济隔离的ICE最大（3.0，95%置信区间[CI] = 2.1至4.3），贫困测量指标最小（1.9，95% CI = 1.4至2.6），而在城市/城镇层面则无关联。然而，在肺癌的类似双层面模型中，对于非西班牙裔黑人和西班牙裔人群，城市/城镇层面的ICE和贫困测量指标的发病率比分别比普查区层面更大（且不包括1）。
我们的研究表明，多层面的种族化经济隔离ICE可用于改进对癌症不平等现象的监测和分析。
