J Sleep Res. 2019;00:e12881. wileyonlinelibrary.com/journal/jsr | 1 of 9 https://doi.org/10.1111/jsr.12881 © 2019 European Sleep Research Society 1 | INTRODUCTION At least 6% of the adult population meet stringent criteria for in‐ somnia disorder (Calem et al., 2012) characterized by difficulties falling asleep at bedtime, waking up in the middle of the night or too early in the morning, combined with daytime symptoms (Edinger et al., 2004). Insomnia disorder is a highly stable condition over time (Buysse, 2008), and causes substantial individual and societal costs (Wickwire, Shaya, & Scharf, 2016). Longstanding insomnia is com‐ mon in patients seeking primary care, affecting 10%–19% (Bjorvatn, Meland, Flo, & Mildestvedt, 2017), and insomnia in primary‐care patients tends to be more serious than insomnia in the general Received: 26 March 2019 | Revised: 1 May 2019 | Accepted: 8 May 2019 DOI: 10.1111/jsr.12881 REGULAR RESEARCH PAPER An open‐ended primary‐care group intervention for insomnia based on a self‐help book – A randomized controlled trial and 4‐year follow‐up Viktor Kaldo 1,2 | Kristoffer Bothelius 3 | Kerstin Blom 1,4 | Maria Lindhe 5,6 | Matilda Larsson 5,6 | Kobra Karimi 5 | Susanne Melder 5 | Viveka Bondestam 3 | Charlotte Ulfsparre 3 | Klara Sternbrink 6 | Susanna Jernelöv 1,7 1 Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, & Stockholm Health Care Services, Stockholm County Council, M58, Karolinska University Hospital Huddinge, Stockholm, Sweden 2 Department of Psychology, Faculty of Health and Life Sciences, Linnaeus University, Växjö, Sweden 3 Department of Psychology, Uppsala University, Uppsala, Sweden 4 Division of Psychiatry, Haukeland University Hospital, Bergen, Norway 5 Department of Psychology, Stockholm University, Stockholm, Sweden 6 Gustavsbergs Primary Care Centre, Stockholm Health Care Services, Stockholm County Council, Stockholm, Sweden 7 Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden Correspondence Kristoffer Bothelius, Department of Psychology, Uppsala University, Box 1225, 751 42 Uppsala, Sweden. Email: kristoffer.bothelius@psyk.uu.se Funding information AFA Försäkring; Stiftelsen Professor Bror Gadelius Minnesfond Summary Chronic insomnia is a common and burdensome problem for patients seeking primary care. Cognitive behavioural therapy has been shown to be effective for insomnia, also when presented with co‐morbidities, but access to sleep therapists is limited. Group‐treatment and self‐administered treatment via self‐help books have both been shown to be efficacious treatment options, and the present study aimed to evalu‐ ate the effect of an open‐ended group intervention based on a self‐help book for insomnia, adapted to fit a primary‐care setting. Forty primary‐care patients with in‐ somnia (mean age 55years, 80% women) were randomized to the open‐ended group intervention based on a cognitive behavioural therapy for insomnia self‐help book or to a care as usual/wait‐list control condition. Results show high attendance to group sessions and high treatment satisfaction. Participants in the control group later re‐ ceived the self‐help book, but without the group intervention. The book‐based group treatment resulted in significantly improved insomnia severity, as well as shorter sleep‐onset latency, less wake time after sleep onset, and less use of sleep medi‐ cation compared with treatment as usual. The improvements were sustained at a 4‐year follow‐up assessment. A secondary analysis found a significant advantage of the combination of the book and the open‐ended group intervention compared with when the initial control group later used only the self‐help book. An open‐ended treatment group based on a self‐help book for insomnia thus seems to be an effective and feasible intervention for chronic insomnia in primary‐care settings. KEYWORDS cognitive behavioural therapy, sleep problems