Comparison of preschool-age children (n = 1017), who after randomization, were lost to follow-up or were retained in the study with regard to age, sex and infection intensity.

Comparison of preschool-age children (n = 1017), who after randomization, were lost to follow-up or were retained in the study with regard to age, sex and infection intensity.本研究就年龄、性别及感染强度，对1017名经随机分组后存在失访或仍保留在研究中的学龄前儿童进行对比分析。