The coronavirus disease (COVID-19) has become a global public health threaten. A series of strict prevention and control measures were implemented in China, contributing to the improvement of air quality. In this study, we described the trend of air pollutant concentrations and the incidence of COVID-19 during the epidemic and applied generalized additive models (GAMs) to assess the association between short-term exposure to air pollution and daily confirmed cases of COVID-19 in 235 Chinese cities. Disease progression based on both onset and report dates as well as control measures as potential confounding were considered in the analyses. We found that stringent prevention and control measures intending to mitigate the spread of COVID-19, contributed to a significant decline in the concentrations of air pollutants except ozone (O 3 ). Significant positive associations of short-term exposure to air pollutants, including particulate matter with diameters ≤2.5μm (PM 2.5 ), particulate matter with diameters ≤10μm (PM 10 ), and nitrogen dioxide (NO 2 ) with daily new confirmed cases were observed during the epidemic. Per interquartile range (IQR) increase in PM 2.5 (lag0-15), PM 10 (lag0-15), and NO 2 (lag0-20) were associated with a 7% [95% confidence interval (CI): (4 - 9)], 6% [95% CI: (3 - 8)], and 19% [95% CI: (13 - 24)] increase in the counts of daily onset cases, respectively. Our results suggest that there is a statistically significant association between ambient air pollution and the spread of COVID-19. Thus, the quarantine measures can not only cut off the transmission of virus, but also retard the spread by improving ambient air quality, which might provide implications for the prevention and control of COVID-19.

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概要 住院患者的红细胞输注量相关研究中, 医院层面和患者层面的因素未得到充分认识. 本研究从医院层面和患者层面这两个角度出发, 将血液中心的供给量纳入考虑范畴, 探讨影响患者红细胞输注数量的因素. 我们从浙江大学医学院附属第一医院的医院信息系统中收集了从 2013 年 1 月至 2020 年 12 月期间病人红细胞的每日使用单位和相应的患者临床信息, 基于每周红细胞总使用单位采用三重指数平滑法进行时间序列分析, 并且以二元逻辑回归方法来追溯影响红细胞输注量的患者相关因素. 研究结果表明, 红细胞的给予单位数量与医院血液库存的季节性趋势和患者的整体状态有关.