Paired t-test of mean percentage of positive coefficients in pre-RECALL and RECALL periods for wEM and woEM groups.

Paired t-test of mean percentage of positive coefficients in pre-RECALL and RECALL periods for wEM and woEM groups.对wEM（with EM）组与woEM（without EM）组在召回前（pre-RECALL）及召回（RECALL）阶段的阳性系数平均占比进行配对t检验（Paired t-test）。