4–6. Who improved and who did not?
As mentioned in section 4–3, not all participants in the treatment group improved their sleep health through the sleep improvement program. According to previous studies, the effects and dropouts of RCTs vary according to individual characteristics, personality traits and level of education (see, for example, Bagby et al. [We use two dependent variables that specify those whose sleep has improved. The first is a binary variable in which one is assigned to those whose The estimation results are presented in 