The Sleep Course: An inclusive trial examining the feasibility, acceptability, and preliminary efficacy of a digital sleep intervention for adults with self-reported sleep difficulties.

Cognitive Behavioural Therapy for Insomnia (CBTi) is a well-established first-line treatment for insomnia and sleep difficulties, yet numerous barriers hinder its widespread adoption. One potential criticism of the existing evidence base for CBTi is that many trials exclude participants that would commonly be seen in in primary care, such as those aged over 65, with comorbid health conditions, or prescribed sleep medication. The current pilot study therefore aimed to assess the acceptability and efficacy of a brief, digitally delivered sleep intervention, the Sleep Course, using a broad range of participants. Participants ( = 74) completed the 6-week, 4-lesson intervention alongside measures of sleep disturbance, sleep-related impairment, depression, anxiety and sleep-wake patterns (via sleep diary). Generalized estimating equations analysis modelled change in participants' outcomes from pre- to post-treatment and 3-month follow-up, and subgroup analyses explored the role of possible moderators (e.g., age over 65, co-morbidities, and concurrent prescription medication use). The intervention was associated with good rates of satisfaction (79 %) and lesson completion (70 %). Results showed significant and large reductions in insomnia, sleep disturbance and associated symptoms (e.g.,  = 1.06-1.37 change in insomnia symptoms). Evidence of high acceptability and clinical improvement was found irrespective of age, physical comorbidity, and sleep medication use. However, there was evidence of less improvement among those taking medications or having tried psychological treatment in the past. These results provide strong preliminary evidence for the intervention as an acceptable, efficacious and scalable treatment for a broad range of participants with sleep difficulties. Larger randomised controlled trials are needed.