Efficacy Study: Comparison of an Insomnia Therapy Developed for Shift Workers with the Standard Treatment (Cognitive Behavioral Therapy for Insomnia) in an Online Group Setting: RCT with an Active Control Group, Completer Analysis

Background. Shift workers are at increased risk for insomnia or shift work disorder. The standard treatment (cognitive behavioral therapy for insomnia) is challenging for this group. Although there are new promising approaches, they are still considered inadequate. Aims and objectives. For the present study, a customized treatment was developed in which interventions on regularity were replaced by methods to treat anxiety or depression, for example. This approach also aims to shift the focus away from disturbed sleep. Methods. Linear mixed models were used (RCT, completer analysis) to compare two active conditions (standard vs. tailored therapy) at three measurement points (pre-, post-treatment, 3-month follow-up). Primary outcomes are sleep quality, insomnia severity, sleep onset latency, and total sleep time. Secondary outcomes are anxiety, depression, tension, concern, emotional instability. Non-inferiority or equivalence tests were also performed. Results. The newly developed treatment is equivalent to standard care. Both resulted in significant and stable improvements in all variables. Thus, only the main effect across measurement points is significant, not the condition or the interaction. Outlook. Future studies should consider attrition and compliance. The treatment should be revised based on these results. The approach of improving sleep with implicit interventions should be pursued further, as it seems well suited to shift workers.