Effects of Aromatherapy on Cancer Patients' Sleep and Fatigue: A Systematic Review and Meta-Analysis.

This study aims at investigating the effectiveness of aromatherapy in enhancing sleep quality and reducing fatigue among cancer patients based on randomized controlled trials (RCTs) with a high level of evidence. A systematic review and meta-analysis. Two reviewers screened and reviewed the full texts of search results obtained from six English databases and four Korean databases, and they extracted data from the selected studies independently. Risk of bias (RoB) was assessed using the revised Cochrane RoB tool for randomized trials. The review protocol was registered with the International Prospective Register of Systematic Reviews (CRD42021277515). Eleven RCTs were included in this study. Aromatherapy significantly improved sleep quality among cancer patients compared with those in the control groups (routine care, no intervention, and placebo) (standardized mean difference [SMD] = -0.92, 95% confidence interval [CI]: -1.39 to -0.46;  < 0.001,  = 89%). However, aromatherapy did not significantly reduce fatigue among such patients (SMD = -0.40, 95% CI: -0.81 to 0.01). The results of the meta-regression confirmed that increased intervention sessions resulted in the enhanced effectiveness of aromatherapy in improving sleep quality among cancer patients ( = -3.86,  < 0.001). This study showed that aromatherapy significantly improves sleep quality among cancer patients. However, aromatherapy does not significantly reduce fatigue among cancer patients. It is possible that the statistical power of the meta-analysis was weak due to the small number of included studies. Therefore, in future studies, the effects of aromatherapy on fatigue among cancer patients should be assessed further using a larger number of included studies. Further, the effects of aromatherapy should be evaluated with a focus on specific subsets of patients, such as specific cancer diagnoses and specific modalities for cancer treatment.