Patients said group sleep restriction was hard, and the group is why it worked

Sleep restriction therapy is the component of cognitive behavioural therapy for insomnia that does most of the work and is hardest to tolerate: patients cut time in bed, often sharply, and feel worse before they feel better. The 2023 HABIT trial showed it can be delivered by nurses in primary care at low cost — 642 adults recruited from 35 general practices across England, with a mean insomnia severity index score at six months of 10.9 for sleep restriction therapy against 13.9 for sleep hygiene (adjusted mean difference −3.05, 95% CI −3.83 to −2.28; p < 0.0001; Cohen's d −0.74), and an incremental cost per quality-adjusted life year of £2,076 [s2].

That trial delivered the therapy one-to-one across four sessions [s2]. A qualitative study published in Sleep Medicine on September 23 examines what happens when it is delivered to groups, interviewing patients from a Swedish randomised trial of nurse-led group sleep restriction therapy in primary care [s1].

What was done

Semi-structured interviews were conducted with 14 adults with insomnia disorder within three months of finishing the intervention [s1]. Verbatim transcripts were analysed with qualitative content analysis, and — importantly for interpretation — the analysis was completed before the trial's outcome results were examined [s1]. The study was guided by the Medical Research Council framework for process evaluation of complex interventions [s1].

Doing the qualitative analysis blind to the trial result is a methodological choice worth noting. It removes the temptation to construct an explanation for a result already known.

What patients described

The findings were organised into two themes: increased knowledge, motivation, and flexibility enhancing adherence to group sleep restriction therapy; and struggles, solutions, and group dynamics as a path to empowerment [s1].

Patients found that understanding sleep reinforced their commitment, by giving them a rationale for participating [s1]. Adherence was influenced by treatment flexibility, personal motivation, and group dynamics [s1]. Patients experienced the therapy as challenging while also finding that it offered solutions for better sleep [s1].

Two things hindered compliance: life circumstances and depressive symptoms [s1].

The authors conclude that experiences were shaped by the patient–provider relationship, motivation, and comorbid depression, all of which affected engagement [s1].

Why the depression finding matters most

Depression and insomnia co-occur at high rates, and sleep restriction is the treatment component that asks most of a patient's capacity to follow through on something unpleasant. If depressive symptoms predict who cannot adhere, then the population most likely to be offered this therapy in primary care overlaps substantially with the population least likely to complete it [s1].

That is a scaling problem, not a therapy problem. It suggests screening or sequencing questions — whether to treat depression first, or to modify the protocol — that a qualitative study can raise but cannot answer.

What a qualitative study can and cannot tell you

Fourteen interviews cannot establish how common any experience was. They establish that the experiences exist and describe their texture, which is what process evaluation is for [s1].

Participants were interviewed within three months of the intervention [s1], so accounts reflect recent recall shaped by whether their sleep had improved. People whose insomnia resolved and people whose did not will narrate the same sessions differently.

The sample is patients who attended. Those who declined the offer or dropped out early are the group most informative about feasibility, and interviews conducted after the intervention will under-represent them.

Crucially, none of this tells you whether group delivery works. The efficacy question belongs to the parent randomised trial, whose results this analysis was deliberately blind to [s1]. Group delivery is attractive because it multiplies scarce nurse time, but a therapy that depends on individually titrated sleep windows may lose something in a group format, and only outcome data can show whether it does.

The context that makes it worth doing

The bottleneck for insomnia care is not evidence but delivery. HABIT's own framing was that access to cognitive behavioural therapy for insomnia is extremely limited, and that sleep restriction therapy has the potential to be widely implemented [s2]. Group delivery is the next step down the same cost curve. Whether it holds up is the open question, and understanding why patients stay or leave is part of answering it.

What to watch

Publication of the Swedish trial's outcome results; whether group delivery matches individual delivery on insomnia severity; and whether protocols adapted for patients with comorbid depressive symptoms improve completion rates.

This article describes qualitative research and a randomised trial, and is informational only. It is not medical advice and does not recommend any treatment.

Sources

• [s1] Bini C, Bäckström J, Årestedt K, Jansson-Fröjmark M, Sandlund C, Patients' experiences of group-delivered sleep restriction therapy in primary care: a qualitative study undertaken alongside a randomized controlled trial, Sleep Medicine, 2025;136:106822, published online 2025-09-23.
• [s2] Kyle SD, Siriwardena AN, Espie CA, et al., Clinical and cost-effectiveness of nurse-delivered sleep restriction therapy for insomnia in primary care (HABIT): a pragmatic, superiority, open-label, randomised controlled trial, The Lancet, 2023;402:975-987, published online 2023-08-10.