Table 2.
Results of subgroup analysis
| Outcome | Source | Sub-categories | Number of studies | Effect size (SMD) | 95% CI | Z | P | I 2 |
|---|---|---|---|---|---|---|---|---|
| Pain | Scale | VAS | 5 | -1.89 | -3.11 to -0.67 | 3.04 | 0.002 | 93.6% |
| NRS | 3 | -1.19 | -1.93 to -0.45 | 3.15 | 0.002 | 79.1% | ||
| Intervention | Inhalation | 5 | -1.93 | -3.11 to -0.75 | 3.20 | 0.001 | 94.0% | |
| Topical | 3 | -1.09 | -1.65 to -0.53 | 1.39 | <0.001 | 56.2% | ||
| Lavender concentration | 100% lavender essential oil | 4 | -1.61 | -2.88 to -0.34 | 2.48 | 0.01 | 94.4% | |
| Diluted oil | 4 | -1.57 | -2.44 to -0.70 | 3.55 | <0.001 | 83.3% | ||
| Control | No intervention | 5 | -2.03 | -2.79 to -1.27 | 5.25 | <0.001 | 79.7% | |
| Placebo | 3 | -0.90 | -2.02 to 0.23 | 1.55 | 0.12 | 93.0% | ||
| Country | Turkey | 5 | -2.18 | -2.64 to -1.72 | 9.37 | <0.001 | 46.4% | |
| Iran | 3 | -0.52 | -1.09 to 0.05 | 1.80 | 0.07 | 70.3% | ||
| RLS | Session | < 9 sessions | 2 | -14.41 | -22.40 to -6.42 | 3.54 | <0.001 | 94.5% |
| ≥9 session | 3 | -12.40 | -18.14 to -6.67 | 4.24 | <0.001 | 93.3% | ||
| Duration | <15 min | 2 | -8.78 | -11.45 to -6.12 | 6.47 | <0.001 | 63.5% | |
| ≥15 min | 3 | -16.35 | -18.70 to -14.01 | 13.68 | <0.001 | 49.3% |
CI: confidence interval; VAS: visual analog scale; NRS: numeric Rating Scale; RLS: restless legs syndrome; SMD: standard mean difference.