From factory floors to dream doors: a systematic review of sleep interventions in industrial workers

In shift work, where sleeping and working is contrary to the usual circadian rhythm, poor sleep is often associated with observed higher risk for worse functioning, health, and well-being. Sleep-enhancing targeted promotion could be a promising work place health intervention to counteract these risk factors. The objective of this study was to systematically review to what extent and with what efficacy sleep interventions are already being used in shift work settings. We searched five databases (PubMed, Cochrane Library, Web of Science, Scopus, and EBSCO, until June 18th, 2024) for any controlled intervention study on shift workers adopting any sleep-enhancing interventions with any control/comparator and any outcome in the context of health, work ability, or sleep. The risk of bias tool II (for RCTs) and, for the non-randomized studies, the ROBINS-I-tool were used for risk of bias ratings. The search yielded 11,261 studies after duplicate removal. Six studies (3 randomized controlled studies (RCTs), 3 non-randomized interventions, 518 participants) could finally be included in this review. Three studies adopted behavioral interventions (cognitive behavioral therapy), one used a pharmacological treatment (melatonin), and two applied an environmental approach (light exposure). Some concerns for an overall risk of bias were given in the RCTs, whilst the non-randomized controlled studies were judged to have a serious overall risk of bias. The efficacy of the interventions was mixed with beneficial and non-beneficial effects regarding the sleep parameters observed. In terms of optimizing industrial workers’ health, well-being and productivity, sleep interventions seem promising. Such interventions can be offered on a low-threshold without interfering everyday (working) life. Future research is needed not only to further prove the efficacy of such interventions, but also to derive practical implications and recommendations for suitable interventions. This systematic review was pre-registered in PROSPERO (CRD42024559360).