Changes before and after the intervention.
(Notes) The graphs show the mean values of Sleep Health Scores 1 and 2 (SH1 and SH2) of 145 participants in the treatment group and 57 participants in the control group at each time point before and after the program. The larger the value on the vertical axis, the better the sleep health is ensured. The p values shown in the figure indicate the results of significance tests for the two groups before and after the program, indicating that although there was no statistically significant difference between the two groups before the intervention, the sleep improvement in the treatment group was statistically significant at the 1% level after the intervention.In the following, we rigorously examine these results by estimating the three models (ANCOVA and two 2SLS models through diligent participation and sleep improvement) explained in the previous section.