Characteristics of the study cohort.

For census tract-level data, the mean and standard deviation across all US census tracts is calculated weighted by the populations in the census tracts. For county-level data, the mean and standard deviation across all US counties is calculated. For individual-level categorical data, the percent of individuals in each category is calculated. For individual-level continuous data, the mean and standard deviation across all individuals in the Public Use Microdata Sample is calculated, using accompanying sampling weights provided by American Community Survey (ACS). Other race denotes races other than White and Black.

针对普查小区（census tract）层级的数据，将以各美国普查小区的人口数为权重，加权计算全美所有普查小区的均值与标准差；针对县（county）层级的数据，将计算全美所有县的均值与标准差；针对个体层级的分类数据，将统计每个分类项下的个体占比；针对个体层级的连续数据，将采用美国社区调查（American Community Survey，ACS）提供的配套抽样权重，计算公共使用微数据样本（Public Use Microdata Sample）中所有个体的均值与标准差。“其他种族”（Other race）指除白人（White）与黑人（Black）之外的种族。