From the Department of Surgery (M.R.P., M.Y.N., A.L., L.A., K.M.K., T.D.), Boston Medical Center, Boston University School of Medicine, Boston, Massachusetts; and Institute for Cancer Outcomes and Survivorship (K.M.K.), University of Alabama-Birmingham, Birmingham, Alabama.
J Trauma Acute Care Surg. 2023 Feb 1;94(2):312-319. doi: 10.1097/TA.0000000000003757. Epub 2022 Aug 5.
Much of the recorded medical literature focuses on individual-level factors that contribute to firearm violence. Recently, studies have highlighted higher incidence of firearm violence in historically redlined and marginalized areas, but few have gone on to study the downstream associations causing these differences. This study aims to understand the effects of historic redlining and current income mobility on firearm violence.
Using a retrospective cross-sectional design, shooting incidents were spatially joined with redlining vector files and linked to income mobility data (how much a child makes in adulthood). Participants included all assault and homicide incidents involving a firearm in the city of Boston, between 2016 and 2019. The exposure of interest was redlining designation as outlined by the Home Owner's Loan Corporation (HOLC) in the 1930s and income mobility, stratified by race, defined as the income of a child in their 30s compared with where they grew up (census tract level). The outcome measured was shooting rate per census block.
We find that increases in Black income mobility (BIM) and White income mobility (WIM) are associated with significant decreases in rates of firearm incidents in all HOLC designations; however, there is a larger decrease with increasing BIM (relative risk, 0.47 per unit increase in BIM [95% confidence interval, 0.35-0.64]; relative risk, 0.81 per unit increase in WIM [95% confidence interval, 0.71-0.93]). Plotting predicted rates of firearm violence in each HOLC designation at different levels of BIM, there were no significant differences in shooting rates between historically harmful and beneficial classifications above $50,000 of BIM. Despite level of WIM, there were continued disparities between harmful and beneficial HOLC classification.
These findings highlight the importance of structural racism in the form of redlining and discriminatory housing policies, and the preclusion from economic mobility therein, on the incidence of firearm violence today.
Prognostic and Epidemiological; Level IV.
大量已发表的医学文献主要关注导致枪支暴力的个体因素。最近，研究强调了枪支暴力在历史上被红线划定和边缘化的地区发生率更高，但很少有人进一步研究导致这些差异的下游关联。本研究旨在了解历史红线划定和当前收入流动性对枪支暴力的影响。
使用回顾性横断面设计，将枪击事件与红线矢量文件进行空间连接，并与收入流动性数据（儿童在成年期的收入）相关联。参与者包括 2016 年至 2019 年期间在波士顿市发生的所有涉及枪支的袭击和凶杀事件。感兴趣的暴露因素是由房主贷款公司（HOLC）在 20 世纪 30 年代制定的红线指定，按种族分层的收入流动性，定义为儿童在 30 多岁时的收入与其成长的地方（普查区）相比。测量的结果是每个普查块的枪击率。
我们发现，黑人和白人收入流动性（BIM）的增加与所有 HOLC 分类中枪支事件发生率的显著下降有关；然而，BIM 的增加与 WIM 的增加相比，下降幅度更大（相对风险，BIM 每增加一个单位，下降 0.47[95%置信区间，0.35-0.64]；相对风险，WIM 每增加一个单位，下降 0.81[95%置信区间，0.71-0.93]）。在不同 BIM 水平的每个 HOLC 分类中绘制枪支暴力的预测率，在 BIM 超过 50,000 美元的历史上有害和有益分类之间，枪击率没有显著差异。尽管 WIM 水平不同，但有害和有益的 HOLC 分类之间仍存在差异。
这些发现强调了以红线和歧视性住房政策形式存在的结构性种族主义以及由此产生的经济流动性障碍对当今枪支暴力发生率的重要性。
预后和流行病学；IV 级。
