Effectiveness of sound and darkness interventions for critically ill patients' sleep quality: A systematic review and component network meta-analysis

Background: Noise and lighting are prime factors of poor sleep quality in critically ill patients, which impair recovery and increase the risk of delirium or complications. Aims: To identify and rank the effectiveness of sound and darkness interventions on the sleep quality of critically ill patients. Methods: This systematic review and component network meta-analysis was based on the Preferred Reporting Items for Systematic Reviews incorporating the Network Meta-Analyses (PRISMA-NMA) Statement. The Embase, MEDLINE, Cochrane CENTRAL, CINAHL, Airiti Library, and Google Scholar databases were searched from inception to August 10, 2021, for randomized controlled trials (RCTs) on sound and darkness interventions targeting critically ill patients' sleep quality. We applied standard and component NMA to determine the effects of interventions. The certainty of evidence was evaluated using the Cochrane risk-of-bias tool (V.2.0) and the online Confidence in Network Meta-Analysis (CINeMA) application. Results: Twenty-four RCTs with 1507 participants who used combined interventions constituting seven competing interventions were included in the standard NMA. The combination of earplugs, eye masks, and music; eye masks alone; earplugs combined with eye masks; and music alone had beneficial intervention effects. The combination of earplugs, eye masks, and music was the best intervention, and these components had no interaction effect. An eye mask had the best relative effect, followed by music, quiet time, and earplugs. Conclusions: This study provides clinical evidence of the effectiveness of using eye masks, music, and earplugs to improve sleep quality in critically ill patients. We also recommend future research using bedtime music, nocturnal eye masks, and quiet time, which had the best relative effects on sleep quality. Relevance to clinical practice: This study provides recommendations for interventions that nurses can use to improve critically ill patients' sleep quality.