Melatonin effects on sleep quality of COVID-19 patients: a protocol for systematic review and meta-analysis of randomised controlled trials with trial sequential analysis

IntroductionSleep disturbance is one of the common complaints of patients with COVID-19 infection. Melatonin is a physiological indoleamine involved in circadian rhythm regulation and it is currently used for secondary sleep disorders caused by various diseases. Some clinical randomised controlled trials (RCTs) have obtained a small amount of evidence and controversial results in support of their therapeutic effect on sleep disorders, but no studies have summarised and evaluated RCTs in all current databases to obtain conclusive results. Therefore, the aim of this systematic review and meta-analysis was to determine the efficacy and safety of melatonin in the treatment of sleep disturbances in patients with COVID-19. Methods and analysisWe will search for RCT-type studies of melatonin in the treatment of sleep disturbances in patients with COVID-19. From inception to October 2022 will be available on PubMed/MEDLINE, Web of Science, Embase, CINAHL, PsycINFO, LILACS, SCOPUS, Cochrane Central Register of Controlled Trials, ICTRP, Wanfang Data, VIP database and CNKI, VIP database, China Biomedical Literature Database to search for eligible studies. There are no language and geographical restrictions. Two authors will independently screen and select eligible studies, assess methodological quality and perform data extraction. Two additional authors will independently extract data from each study. Then, meta-analysis will then be carried out using a fixed-effects or random-effects model, using the mean difference for continuous outcomes and the relative risk for dichotomous outcomes. Risk of bias assessment will be assessed using the Cochrane risk-of-bias tool. Heterogeneity between studies was assessed by Cochrane Q-test and I-2. The quality of evidence for each outcome will be assessed using the Grading of Recommendations Assessment, Development and Evaluation methodology. Funnel plots, Begg's test and Egger's test will be used to assess the risk of publication bias. Subgroup analysis, data synthesis, meta-analysis and overall incidence of adverse events will be performed using Review Manager V.5.4 software and Stata software. Trial sequential analysis will be performed if appropriate. Ethics and disseminationThis study is an extraction review of data from existing studies, and thus it is unnecessary to obtain ethical approval. The results of this systematic review will be published in a peer-reviewed journal. PROSPERO registration numberCRD42022359221.