Cognitive-behavioral treatment for insomnia and mindfulness-based stress reduction in nurses with insomnia: a non-inferiority internet delivered randomized controlled trial

Background. Insomnia is a highly prevalent sleep disorder frequently comorbid with mental health conditions in nurses. Despite the effectiveness of evidence-based cognitive behavioral therapy for insomnia (CBT-I), there is a critical need for alternative approaches. This study investigated whether internet-delivered mindfulness-based stress reduction (IMBSR) for insomnia could be an alternative to internet-delivered CBT-I (ICBT-I). Objective. The hypothesis was that the IMBSR would be noninferior to the ICBT-I in reducing the severity of insomnia among nurses with insomnia. Additionally, it was expected that ICBT-I would produce a greater reduction in the severity of insomnia and depression than IMBSR. Method. Among 240 screened nurses, 134 with insomnia were randomly allocated (IMBSR, n = 67; ICBT-I, n = 67). The assessment protocol comprised clinical interviews and self-reported outcome measures, including the Insomnia Severity Index (ISI), Patient Health Questionnaire-9 (PHQ-9), the 15-item Five Facet Mindfulness Questionnaire (FFMQ), and the Client Satisfaction Questionnaire (CSQ-I). Results. The retention rate was 55% with 77.6% (n = 104) of participants completing the study. At post-intervention, the noninferiority analysis of the ISI score showed that the upper limit of the 95% confidence interval was 4.88 (P = 0.46), surpassing the pre-specified noninferiority margin of 4 points. Analysis of covariance revealed that the ICBT-I group had significantly lower ISI (Cohen's d = 1.37) and PHQ-9 (Cohen's d = 0.71) scores than did the IMBSR group. In contrast, the IMBSR group showed a statistically significant increase in the FFMQ-15 score (Cohen's d = 0.67). Withingroup differences showed that both the IMBSR and ICBT-I were effective at reducing insomnia severity and depression severity and improving mindfulness. Conclusion. Overall, nurses demonstrated high levels of satisfaction and adherence to both interventions. The IMBSR significantly reduced insomnia severity and depression, but the findings of this study do not provide strong evidence that the IMBSR is at least as effective as the ICBT-I in reducing insomnia symptoms among nurses with insomnia. The ICBT-I was found to be significantly superior to the IMBSR in reducing insomnia severity, making it a recommended treatment option for nurses with insomnia.