Is cognitive behavioral therapy for insomnia (CBTi) efficacious for treating insomnia symptoms in shift workers? A systematic review and meta-analysis.

Shift workers commonly report insomnia symptoms. Cognitive behavioral therapy for insomnia (CBTi) is the first line treatment for insomnia, however efficacy in shift workers is not well understood. This systematic review and meta-analysis evaluates existing trials of CBTi in shift working populations. A systematic literature search was conducted across seven electronic databases (n = 2120). Fifty-two full-text articles were reviewed and of these, nine studies (across ten publications with a total of 363 participants) were deemed suitable for inclusion. Heterogeneity was considerable between studies, with variability in study design, style and delivery of intervention, and follow-up times. Small sample sizes were common and attrition was high. Some studies modified aspects of CBTi for use in shift workers, while others were limited to psycho-education as part of larger intervention studies. Mean differences (MD) pre and post CBTi were modest for both the insomnia severity index (ISI; MD: -3.08, 95% CI: -4.39, -1.76) and the Pittsburgh sleep quality index (PSQI; MD: -2.38, 95% CI: -3.55, -1.21). Neither difference was of a magnitude considered to reflect a clinically significant improvement. Tailored approaches to CBTi are needed for shift workers to improve efficacy, ideally including co-production with workers to ensure interventions meet this population's needs.