The Effects of Aromatherapy on Sleep Improvement: A Systematic Literature Review and Meta-Analysis

OBJECTIVES: To evaluate the existing data on aromatherapy interventions for improvement of sleep quality. DESIGN: Systematic literature review and meta-analysis on the effects of aromatherapy. Study Sources: Electronic databases, including the Korea Education and Research Information Service (KERIS), Korean studies Information Service System (KISS), National Assembly Library, and eight academies within the Korean Society of Nursing Science, were searched to identify studies published between 2000 and August 2013. STUDY SELECTION: Randomized controlled and quasi-experimental trials that included aromatherapy for the improvement of sleep quality. Of the 245 publications identified, 13 studies met the inclusion and exclusion criteria, and 12 studies were used in the meta-analysis. RESULTS: Meta-analysis of the 12 studies using a random-effects model revealed that the use of aromatherapy was effective in improving sleep quality (95% confidence interval [CI], 0.540-1.745; Z=3.716). Subgroup analysis revealed that inhalation aromatherapy (95% CI, 0.792-1.541; Z=6.107) was more effective than massage therapy (95% CI, 0.128-2.166; Z=2.205) in unhealthy (95% CI, 0.248-1.100; Z=3.100) and healthy (95% CI, 0.393-5.104; Z=2.287) participants, respectively. CONCLUSION: Readily available aromatherapy treatments appear to be effective and promote sleep. Thus, it is essential to develop specific guidelines for the efficient use of aromatherapy.