Clinical effectiveness of internet-based cognitive behavioral therapy for insomnia in routine secondary care: results of a randomized controlled trial.

Introduction: Delivering cognitive behavioral therapy for insomnia over the internet bears the advantage of accessibility and uptake to many patients suffering from chronic insomnia. In the current study, we aimed to investigate the effectiveness of internet-based cognitive behavioral therapy for insomnia (iCBT-I) in routine care. Materials and methods: We conducted a two-arm non-blinded randomized controlled trial with care as usual (CAU) as a control condition. Participants were recruited in a specialized outpatient sleep medicine department. Both arms had access to other healthcare resources, and the intervention group had access to the iCBT-I program for 2 months. The primary outcome was insomnia severity, measured by the Insomnia Severity Index (ISI). Secondary outcomes were fatigue severity, daytime sleepiness, affective symptoms, dysfunctional beliefs and attitudes about sleep, sleep locus of control, sleep hygiene, sleep efficiency (SE), sleep onset latency, wake time after sleep onset (WASO), and total sleep time (TST). Linear mixed models for repeated measures were used to analyze the longitudinal data at baseline, post-treatment, and after 3 months of follow-up. The trial was registered at www.clinicaltrials.gov (NCT04300218 21.04.2020). Results: The results showed a significant time*group interaction effect ( Conclusion: Our findings suggest that iCBT-I has a significant effect on insomnia severity at post-treatment compared to CAU. iCBT-I further improved dysfunctional beliefs about sleep and improved subjective sleep characteristics, such as SE, WASO, and TST during 3 months after treatment. Clinical trial registration: www.clinicaltrials.gov, identifier (NCT04300218).