A systematic literature review and meta-analysis of the clinical effects of aroma inhalation therapy on sleep problems.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of clinical studies
PubMed 33655928 · doi:10.1097/MD.0000000000024652
What was done
Researchers performed a systematic review and meta-analysis across 10 databases (5 Korean domestic and 5 international) examining the clinical effects of aroma inhalation therapy for sleep problems such as insomnia. Risk of bias was evaluated using RevMan 5.0. A random-effects meta-analysis was conducted on numerical outcomes alongside meta-regression and subgroup analyses.
What was found
Across 34 studies, inhalation aromatherapy showed a significant positive effect on quantitative and qualitative sleep measures, reporting an effect size of 0.6491 (95% CI bounds not provided in the abstract). Secondary outcomes including stress, depression, anxiety, and fatigue were also significantly improved. Subgroup analysis showed single-oil inhalation was more effective than blended oils, with lavender demonstrating the largest individual effect.
Why it matters
This meta-analysis synthesizes regional and global evidence showing that single-agent inhalation aromatherapy, especially lavender, is an effective non-pharmacological strategy for improving sleep disturbances and associated mood symptoms.
Limits
The abstract does not state the total participant count, exact 95% confidence intervals, p-values, or between-study heterogeneity metrics (I²). It does not clarify whether all 34 studies were randomized controlled trials, and inhalation studies often suffer from difficulty in blinding participants to aromatic interventions.
Cited by
- supports The scent of lavender is moderately associated with helping people fall asleep.