The "SleepWell" intervention for patients with insomnia and persistent pain: a study protocol for a randomised waiting-list controlled trial of a cognitive behavioural group therapy programme.

Background: Patients with persistent pain and comorbid insomnia often experience a dual burden with significant day- and nighttime impairments. This comorbidity is associated with health problems like depression and a self-perpetuating vicious circle in which pain and insomnia symptoms mutually reinforce each other. Cognitive behavioural therapy for insomnia (CBT-i) has demonstrated efficacy in facilitating the behavioural and psychological changes necessary to improve sleep. However, its applicability to patients with the insomnia-pain comorbidity condition is underexplored. We will expand the knowledge base of CBT-i to this patient group by examining the effects on core insomnia symptoms, including sleep onset, the frequency and duration of nightly and early morning awakenings, sleep efficiency and daytime impairments at post-test and follow-up. Secondary outcomes include reductions in pain intensity and interference, depression and fatigue; improved pain acceptance and quality of life; and more adaptive sleep-related beliefs. This study also explores mediators of the expected effects, patient experiences of the feasibility and acceptability of the intervention and how these experiences relate to individual differences in treatment benefits.

Methods: The study includes hospital patients with a chronic pain condition according to the criteria from the International Association for the Study of Pain and a DSM-5 diagnosis of insomnia. The study will recruit 106 patients based on a power analysis that accounts for 20% dropout, and block-randomise them to a group-based CBT-i intervention or treatment as usual (TAU). The latter consists of consultations and potential pain- and sleep medication. The participant timeline includes a baseline registration, seven sessions of the CBT-i within a 10-week period, a post-test and two follow-up measurements at 4 and 12 months, respectively. The statistical analyses will be intention-to-treat and include random factors to adjust for data dependencies. Patients' experiences of feasibility and acceptability will be analysed using a reflexive thematic approach.

Discussion: This study addresses a knowledge gap by evaluating the effectiveness of CBT-i adapted for patients with insomnia and non-malignant, persistent pain. Given positive findings, the study may support clinical recommendations by providing empirical evidence for implementing psychological sleep interventions for somatic hospital patients having comorbid sleep issues.

Trial Registration: Clinical Trials.gov ID NCT06351839. Registered 08 April 2024.