Data from: Disparities in influenza mortality and transmission related to sociodemographic factors within Chicago in the pandemic of 1918

Social factors have been shown to create differential burden of influenza across different geographic areas. We explored the relationship between potential aggregate-level social determinants and mortality during the 1918 influenza pandemic in Chicago using a historical dataset of 7,971 influenza and pneumonia deaths. Census tract-level social factors, including rates of illiteracy, homeownership, population, and unemployment, were assessed as predictors of pandemic mortality in Chicago. Poisson models fit with generalized estimating equations (GEEs) were used to estimate the association between social factors and the risk of influenza and pneumonia mortality. The Poisson model showed that influenza and pneumonia mortality increased, on average, by 32.2% for every 10% increase in illiteracy rate adjusted for population density, homeownership, unemployment, and age. We also found a significant association between transmissibility and population density, illiteracy, and unemployment but not homeownership. Lastly, analysis of the point locations of reported influenza and pneumonia deaths revealed fine-scale spatiotemporal clustering. This study shows that living in census tracts with higher illiteracy rates increased the risk of influenza and pneumonia mortality during the 1918 influenza pandemic in Chicago. Our observation that disparities in structural determinants of neighborhood-level health lead to disparities in influenza incidence in this pandemic suggests that disparities and their determinants should remain targets of research and control in future pandemics.

研究表明，社会因素会导致不同地理区域间流感疾病负担存在差异。本研究依托包含7971例流感与肺炎死亡病例的历史数据集，探究了1918年芝加哥流感大流行期间，潜在聚合层面社会决定因素与死亡率之间的关联。本研究将普查分区（census tract）层面的社会因素——包括文盲率、房屋自有率、人口规模与失业率——作为芝加哥流感大流行死亡率的预测因子进行评估。本研究采用结合广义估计方程（generalized estimating equations, GEE）的泊松模型（Poisson model），估算社会因素与流感及肺炎死亡风险之间的关联。泊松模型结果显示，在对人口密度、房屋自有率、失业率及年龄进行校正后，文盲率每升高10%，流感与肺炎死亡率平均上升32.2%。本研究同时发现，病毒传播能力与人口密度、文盲率及失业率存在显著关联，但与房屋自有率无显著关联。最后，对报告的流感与肺炎死亡病例的点位信息进行分析后，本研究发现了精细尺度的时空聚集现象。本研究证实，在1918年芝加哥流感大流行期间，居住在文盲率更高的普查分区会提升流感与肺炎的死亡风险。本研究观察到，社区层面健康的结构决定因素差异会导致本次大流行中流感发病情况的差异，这提示在未来的大流行应对中，社会差异及其决定因素仍应作为研究与防控的重点目标。