深圳市学龄儿童接种流感疫苗对缺课预防效果的实证研究

目的 评估深圳市采用入校接种方式以及学龄儿童流感疫苗接种率高低对缺课的影响。方法 以深圳市小学学龄儿童为研究对象，利用2017年12月至2020年6月深圳市286所小学缺课数据以及学龄儿童流感疫苗接种政策实施后深圳市9个区疫苗接种率和组织方式（入校接种与非入校接种）数据，以缺课人数作为被解释变量，分别以组织方式和区接种率作为分组变量，构建双重差分模型，采用泊松回归进行分析，并对回归结果进行稳健性检验。结果 相比于非入校接种和低接种率，入校接种和高接种率可有效降低缺课的发生风险，对缺课的预防效果分别为32.6%（95%CI： 17.0%~45.3%，P<0.01）和53.0%（95%CI：42.1%~61.8%，P<0.01）。结论 深圳市实施学龄儿童流感疫苗免费接种政策并优先采用入校接种的方式，可有效降低学生缺课的发生风险。

Effectiveness of influenza vaccination for school-age children in preventing school absenteeism in Shenzhen: an empirical study

Objective To assess the impact of vaccination at school and influenza vaccination rates among school-age children on school absenteeism in Shenzhen. Methods The study subjects were primary school students in Shenzhen. School absenteeism panel database from December 2017 to June 2020 of 286 primary schools in Shenzhen was merged with vaccination rates and organizational patterns (i.e., vaccination at school vs. non-school) data of 9 districts in Shenzhen after influenza vaccination for children. The outcome was the number of school absenteeism. The treatment and control groups were distinguished by organizational patterns and district vaccination rates. Difference-in-Difference (DiD) Poisson regressions were used to analyze the effectiveness of vaccination at school and higher vaccination rates. Besides, a robustness test was performed on the regression results. Results Poisson regression analysis and robustness test of regression results showed that vaccination at school and higher vaccination rates effectively reduced the risk of school absenteeism, with effectiveness against absenteeism of 32.6% (95%CI:17.0%-45.3%, P<0.01) and 53.0% (95%CI:42.1%-61.8%, P<0.01), respectively. Conclusion A free influenza vaccination program for school-age children in Shenzhen and prioritizing school-based vaccination may be an effective measure to reduce the risk of school absenteeism.