Characteristics of the participants and baseline differences between the groups
The sample consisted of 69 female nurses (93.2%) and 5 male nurses (6.8%), with a mean age of 31.7 years (SD = 5.4) and a mean duration of emergency practice of 10.1 years (SD = 5.8). Most of the nurses were married (n = 53, 71.6%), 64 (86.5%) had obtained a bachelor’s degree, and 54 (72.9%) held junior titles. There were no differences between the groups in demographic and clinical characteristics, as well as baseline outcome scores (see Table 1).
Effects of the intervention: Disparities between groups
The outcome data were consistent with homogeneity of variance and a normal distribution. Table 2 presents descriptive statistics of the mean scores of outcomes at baseline, post-intervention, and 1-month follow-up. It also includes group comparisons based on time, the main effect of the group, and the interaction effect of the time group in the MBSR and comparison group. We observed significant time effects for PTSD symptoms (F = 5.947, P= 0.003, partial η2 = 0.076), emotional exhaustion (F = 4.584, P = 0.012, partial η2 = 0.060), and mindfulness (F = 4.342, P = 0.019, partial η2 = 0.057). Additionally, we found significant time group interaction effects for PTSD symptoms (F = 4.174, P = 0.017, partial η2 = 0.055) and emotional exhaustion (F=3.152,P =0.046, partial η2=0.042). Regarding the difference between the groups, the results showed significant effects only on the post-intervention scores of PTSD symptoms (F=5.916,P =0.017, 95%CI =1.492~15.054). The time effect, the main effect of the group, and the interaction effect of the time and group for two coping styles were not significant.
Effects of the intervention: Pre-post disparities
Simple main effects tests with Bonferroni correction revealed significant changes in the main outcomes over time for both groups (see Table 3). There was a significant decrease in symptoms of PTSD (M (I-J) = -7.789,P <0.001, 95%CI =3.642~11.937) and emotional exhaustion (M(I-J)=4.763, P =0.004, 95%CI =1.274~8.253) and an increase in mindfulness (M(I-J)=-7.421, P <0.001, 95%CI =-12.349~2.493) from before to post-test in the MBSR group, while no significant changes were found in the comparison group. There were no significant differences in any outcomes between the post-test and the 1-month follow-up test in the MBSR group.