Background: Sleep restriction therapy (SRT) is an effective and brief behavioral treatment for insomnia and could serve as a valuable complement to insomnia care. This study explores patients' experiences of being offered and attending group-SRT at their primary care centers, including experiences of feasibility and mechanisms of impact.

Methods: This qualitative study was undertaken alongside a randomized controlled trial on nurse-led group-SRT in Swedish primary care, involving adults with insomnia disorder. Semi-structured interviews were conducted within three months post-intervention with fourteen patients. Verbatim transcripts were analyzed using qualitative content analysis before trial results were examined. The study was guided by the Medical Research Council framework for process evaluation of complex interventions.

Results: The result is presented in two themes: Increased knowledge, motivation, and flexibility in enhancing adherence to group-SRT and Struggles, solutions, and group dynamics: A path to empowerment. Patients found that understanding sleep reinforced their commitment to group-SRT by providing a rationale for participation. Adherence was influenced by treatment flexibility, personal motivation, and group dynamics. Patients experienced that while group-SRT was challenging, it also offered solutions for better sleep. However, life circumstances and depressive symptoms hindered compliance.

Conclusions: Patients' experience of group-SRT were influenced by the patient-provider relationship, motivation, and comorbid depression, all which impacted engagement. This study provides valuable insights into how patients perceive group-SRT, contributing to the refinement of future insomnia treatments. Further research should explore healthcare providers' perspectives on both the challenges and opportunities for implementing group-SRT in primary care.